bluuebunny/crossref_metadata_2025 huggingface dataset:
Graft copolymerization onto Tamarind Kernel Powder: Ceric(IV)‐initiated graft copolymerization of acrylonitrile
Authors: Goyal Puja , Kumar Vineet , Sharma Pradeep
Published: June 2009

Tamarind Kernel Powder (TKP) is derived from the seeds of Tamarindus indica Linn., a common and most important tree of India. It is extensively used in cotton sizing, as a wet‐end additive in the paper industry, as a thickening, stabilizing, and gelling agent in the food industry. However, because of its fast biodegradability there is a need to prepare graft copolymers of TKP. The graft copolymerization of acrylonitrile (AN) onto TKP with ceric ammonium nitrate as a redox initiator in an aqueous medium has been studied. The reaction conditions were optimized to afford maximum percent grafting and percentage grafting efficiency of AN onto TKP, which was found to be 86% and 64%, respectively. Fourier Transform Infrared Spectrum of the grafted products showed an additional sharp absorption band at 2244 cm−1 due to CN stretching, thereby confirming the grafting of AN onto TKP. Scanning electron microscopy studies indicated change in contour of the polysaccharide on grafting and the thick polymeric coating of AN on the surface alongwith grafting of AN such that all the gap between polysaccharide particles have been closed. Thermal studies using thermogravimetric and differential gravimetric analyses confirmed that TKP‐g‐AN has overall high thermal stability than pure TKP. Reaction mechanism of grafting of acrylnitrile onto TKP is also proposed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Photocatalytic properties of silicone polyesters using calcium phosphate/titanium dioxide
Authors: Chu Hawn‐Chung , Lin Li‐Huei , Liu Hsin‐Chi , Chen Ho‐Fu , Liu Hsin‐Jiant , Chen Keng‐Ming
Published: June 2009

This study uses titanium dioxide treated with calcium phosphate to prepare multilayer structure composites. These products are regarded as photocatalysts. Utilizing polyethylene glycol (PEG)–silicone polyester as an adhesive spread on matrix surfaces, this can provide these products with antifouling properties, good weather resistance, and antibacterial property. It has been observed that UV irradiation has caused changes in the film molecular structure of PEG–silicone polyesters, as well as changes in the surface morphology. These changes in molecular structure have been observed by FTIR and Raman analysis. PEG–silicone polyesters contain silicon atoms with both organic and inorganic characteristics. This makes fixation of photocatalysts possible and retards oxidation of organic materials in the polyesters. The results of FTIR and Raman spectrum analyses indicate films made of these polyesters effectively cover calcium phosphate–titanium dioxide photocatalysts, retard surface cracks, and slow down decomposition, caused by UV light. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of dodeca‐tungstophosphric acid on morphology and performance of polyvinyl alcohol membrane for gas separation
Authors: Madaeni S. S. , Rafiee E. , Seyedzadeh Z. , Barzin J.
Published: June 2009

In this article, organic/inorganic membrane was prepared for gas separation by incorporating dodeca‐tungstophosphric acid (PWA) into the base polymer. Flat‐sheet composite membranes were produced via dry‐phase inversion method. In the first stage, the effects of PWA concentration on morphology and performance of polyvinyl alcohol (PVA) membranes were elucidated. For this stage, the preparation of membranes was carried out at constant temperature of 40°C. The porosity of the prepared membrane was slightly increased with addition of PWA. By increasing the PWA concentration up to 6 wt % in the membrane recipe, the permeability of N2, O and air was improved from 50,000 (for no addition of PWA) to around 160,000, 140,000, and 80,000 L m−2 h−1, respectively. For H this was enhanced from 110,000 to 230,000 L m−2 h−1. The ideal selectivity of the membrane was slightly improved for N2/air (from 1 to 1.2). For N2/O2 pair, the initial drop (from 2.5 to 1.5) was followed by a slight increase (1.5–1.9). Moreover, the selectivity was decreased for H2/air (from 2.8 to 1.8) and H2/N2 (from 2.2 to 1.7) by increasing the PWA concentration. The 10 wt % PVA membrane with 6 wt % PWA demonstrated superior performance compared with the other compositions. In summary, the presence of PWA in the casting solution results in lower flux for O2 and higher selectivity for H2/O2 pair. In the second stage, the effects of solvent evaporation temperature (10, 27, 40, and 80°C) on morphology and performance of the membranes were studied. By increasing the temperature, the number and size of voids were increased. The permeation of gases was improved from 100,000 L m−2 h−1 (at 10°C) to 150,000 (O2), 250,000 (air), 380,000 (N2), and 600,000 L m−2 h−1 (H2) by increasing the temperature up to 80°C. This increment resulted in selectivity alteration either increment or diminishment. The selectivity was changed from 1.3 to 3.2 (H2/O2), 0.8–2.5 (N2/O2), 1.2–2.4 (H2/air), 0.6–1.5 (N2/air) and 2.0–1.5 (H2/N2). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Mechanistic study of Sn(Oct)2‐catalyzed ε‐caprolactone polymerization using Sn(Oct)2/BF3 dual catalyst
Authors: Jiang G. , Jones I. A. , Rudd C. D. , Walker G. S.
Published: June 2009

A novel method was used to investigate the mechanism of Sn(Oct)2‐catalyzed ε‐caprolactone polymerization by using Sn(Oct)2/BF3 dual catalyst. The bulk polymerization was conducted at 110 and 130°C with different Sn(Oct)2/BF3 ratios. The polymerization kinetics was followed using gel permeation chromatography, and the molecular structures of the low‐molecular weight polymers were examined using 1H‐nuclear magnetic resonance (NMR). A polymerization induction period was observed in polymerizations containing the Sn(Oct)2 catalyst, but it was not observed in the system containing only BF3. After the induction period, BF3 and Sn(Oct)2 initiated the polymerization separately. For Sn(Oct)2 catalyst with no purposely added alcohol, the actual initiation species is a tin hydroxide species formed in situ by the reaction of Sn(Oct)2 and adventitious water. For BF3 catalyst, the active species is the protonic acid formed by the reaction of BF3 with the adventitious water. When mixed, the Sn(Oct)2 reacts with the adventitious water faster than the BF3, preventing the BF3 catalyzing any polymerizations during the induction period. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A new method to prepare porous silk fibroin membranes suitable for tissue scaffolding applications
Authors: Nogueira Grínia M. , Weska Raquel F. , Vieira Wellington C. , Polakiewicz Bronislaw , Rodas Andrea C. D. , Higa Olga Z. , Beppu Marisa M.
Published: June 2009

A new method to prepare porous silk fibroin (SF) membranes without dialysis is proposed. Silk fibers were degummed to remove sericin and the resultant fibroin was dissolved in a CaCl2‐CH3CH2OH‐H2O ternary solvent. Rather than undergoing dialysis, a fibroin salty solution was diluted in water and then submitted to a mechanical agitation that led to a phase separation through foam formation on the solution surface. This foam was continually collected and then compacted between plates to remove the excess of water. The membranes presented large pores with diameters of greater than 100 μm (as shown by scanning electron microscopy ‐ SEM), porosity of 68% and water content of 91% w/w. X‐ray diffraction (XRD) and infrared spectroscopy (FTIR‐ATR) indicated that the membranes present SF in a β‐sheet structure even before the ethanol treatment. A typical elastic deformation profile and degradation under temperature were observed using calorimetric analysis (DSC), thermal gravimetric analysis (TGA) and mechanical tests. As indicated by the in vitro cytotoxicity tests, these membranes present potential for use as scaffolds. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A rationale for the Hirsch‐index rank‐order distribution and a comparison with the impact factor rank‐order distribution
Authors: Egghe Leo
Published: June 2009

We present a rationale for the Hirsch‐index rank‐order distribution and prove that it is a power law (hence a straight line in the log–log scale). This is confirmed by experimental data of Pyykkö and by data produced in this article on 206 mathematics journals. This distribution is of a completely different nature than the impact factor (IF) rank‐order distribution which (as proved in a previous article) is S‐shaped. This is also confirmed by our example. Only in the log–log scale of the h‐index distribution do we notice a concave deviation of the straight line for higher ranks. This phenomenon is discussed.
Der aktuelle Gebrauch der ‘longue durée’ in der Wissenschaftsgeschichte
Authors: Stoff Heiko
Published: June 2009

On the Contemporary Uses of ‘Long Durée’ in the History of Science. In the last years, Fernand Braudel's concept of ‘longue durée’ has been widely used in the German history of science. It thereby served as a historiographical tool for the problem of continuity and discontinuity with regard to the political ruptures of the years 1914, 1918, 1933, and 1945. In the context of historical innovation research, these political events seemed to have discontinued an otherwise ‘longue durée’ of a successful German innovation system, established in the German Empire. Critics of this narrative again stress the continuing functionality of a national innovation system also in the Third Reich. While the first group strengthens the negative impact of political events on a ‘longue durée’ of the German innovation system, thereby constructing a positive and politically charged interpretation of a scientific German ‘Sonderweg’, the latter emphasizes the catalytic role of these events, its function as a reorganizer of research. For this interpretation different methodologies like research ensembles and networks, based on Bruno Latour's non‐structural sociology of practices and interests, proved to be more adequate. Paul Rabinow's use of the term ‘assemblage’ as a contingent, temporal ensemble of practices, actors, structures, routines, value systems and self technologies again places the event at the basis of the historical analysis. While Hans‐Jörg Rheinberger's concept of experimental systems relates to this characterisation of assemblage, it also corresponds to Michel Foucault's reading of Braudel's concept of ‘longue durée’. Foucault fundamentally neglected the separation of event and structure in establishing a connection between series and events based on transformations, thereby avoiding both a totalizing macro history and an individualizing micro history. A future ‘longue durée’‐history, which transgresses the dichotomy of continuity and discontinuity, therefore can be conceptualized as a series of multi‐temporal non‐causal occurrences.
Gangarten des Rationalen. Zu den Zeitstrukturen der Quantenrevolution
Authors: Stöltzner Michael
Published: June 2009

Paces 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

Whole‐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

Adenosine 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

Adsorption 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

Tight 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

Every 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

General 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

Coming 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.

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In 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

Stable 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).

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In 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

Unraveling 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.

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A 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

This 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

Similarly 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

Study 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

The 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
Automated loop identification on DSL lines
Authors: Kerpez Kenneth J.
Published: June 2009

Regular ADSL and new FTTN VDSL2 deployments are strongly affected by the telephone loop, or channel, that they transmit over. Telephone companies keep records of the loop make‐up—all cable sections, gauges, lengths and bridged taps between the DSLAM and customer, and these records are vital for loop qualification and maintenance. However, loop records are often incomplete or inaccurate due to re‐work. New ADSL2, ADSL2 + and VDSL2 equipment can automatically report loop response estimates, and this paper shows how this response can be used to identify an estimate of the loop make‐up. The algorithm for loop identification here is shown to be more accurate than previous, simple, techniques. Copyright © 2009 John Wiley & Sons, Ltd.
Phosphate Ester Hydrolysis: Metal Complexes As Purple Acid Phosphatase and Phosphotriesterase Analogues
Authors: Gahan Lawrence R. , Smith Sarah J. , Neves Ademir , Schenk Gerhard
Published: June 2009

This microreview describes the structures and properties of a number of bimetallic complexes designed as both structural and functional mimics of the active sites of some specific metallohydrolase enzymes. The metalloenzymes in question include the predominantly monoesterase‐activity‐displaying purple acid phosphatase (PAP) and di‐ and triesterase enzymes, which have significant roles in the bioremedial hydrolysis of organophosphate pesticides and nerve gases. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Study on Sensitization from Reactive Oxygen Species for Electrochemiluminescence of Luminol in Neutral Medium
Authors: Chu Haihong , Guo Wenying , Di Junwei , Wu Ying , Tu Yifeng
Published: June 2009

In this paper, the sensitization on electrochemiluminescent (ECL) reaction of luminol from reactive oxygen species (ROSs) in neutral medium was studied. The powerful sensitization from ROSs even related with organics and organisms were examined under selected conditions which were suitable for biochemical analysis. The results indicated that whether the enhancers were dissolved in solutions or immobilized on the surface of conventional electrodes, stronger ECL intensity of luminol could be obtained. Enhanced ECL helped to provide groundwork for the detection of biomolecules for which would further enhance or quench the ECL signals. The technique may provide new means in a variety of fields such as clinical diagnostics, immunological analysis and environmental monitoring due to its simplicity and high efficiency.
One‐Step Electrochemically Deposited Nanocomposite Film of CS‐Fc/MWNTs/GOD for Glucose Biosensor Application
Authors: Liang Ru‐Ping , Fan Li‐Xia , Wang Rui , Qiu Jian‐Ding
Published: June 2009

A simple and controllable electrodeposition approach was proposed for one‐step construction of glucose biosensors by in situ co‐deposition of ferrocene‐branched chitosan derivatives (CS‐Fc), multiwalled carbon nanotubes (MWNTs), and glucose oxidase (GOD) onto electrode surface. The formation of CS‐Fc could not only effectively prevent the leakage of Fc and retain its electrochemical activity, but also provide a biocompatible microenvironment for retaining the native activity of the immobilized biomolecules. Further entrapment of MWNTs into the CS matrix improved electronic conductivity of the biocomposite significantly. The facile procedure of immobilizing GOD and the promising feature of biocomposite will offer a versatile platform to fabricate biosensors and bioelectronic devices.
Functionalized Gold Nanoparticles – Octadecylamine Hybrid Langmuir‐Blodgett Film for Enzyme Sensor
Authors: Matharu Zimple , Pandey Pratibha , Pandey M. K. , Gupta Vinay , Malhotra B. D.
Published: June 2009

Mediator free enzyme sensor has been fabricated by covalently immobilizing cholesterol oxidase (ChOx) onto 11‐mercaptoundecanoic acid functionalized gold nanoparticles (MUDA‐AuNPs) – octadecylamine (ODA) hybrid Langmuir–Blodgett film. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) studies reveal that MUDA‐AuNP/ODA LB film has good affinity for ChOx and provides favorable microenvironment for direct electron transfer between enzyme and electrode. Interference free estimation of cholesterol has been realized at 0.3 V with linear range from 25 to 500 mg/dL, detection limit of 23.38 mg/dL, sensitivity of 1.085 μA mM−1 and response time of 20 s at pH 7.0.
Real Time Electrochemical Monitoring of DNA/PNA Dissociation by Melting Curve Analysis
Authors: Luo Xiaoteng , Hsing I‐Ming
Published: June 2009

An immobilization‐free electrochemical method is reported for real‐time monitoring of the DNA hybrid dissociation between a ferrocene labeled peptide nucleic acid (PNA) and a fully‐complementary or single‐base‐mismatched DNA. This method takes advantages of electrostatic charge characteristics and interactions among the neutrally charged PNA, the negatively charged DNA and the negatively charged electrode surface made of indium tin oxide (ITO). When a ferrocene labeled PNA (Fc‐PNA) sequence is hybridized to a complementary DNA strand, electrostatic repulsion between the negatively charged PNA/DNA hybrid and the negative ITO surface retards the diffusion of the electroactive Fc to the electrode, resulting in a much reduced electrochemical signal. On the other hand, when the Fc‐PNA is dissociated from the hybrid at elevated temperatures, the neutrally charged Fc‐PNA easily diffuses to the electrode with an enhanced electrochemical signal. Therefore, an electrochemical melting curve of the Fc‐PNA/DNA hybrid can be obtained by measuring the Fc signal with the increasing temperature. This strategy allows monitoring of the dissociation of the DNA hybrid in real time, which might lead to a simple detection method for single nucleotide polymorphism (SNP) analysis.
Time horizons in evaluating environmental policies
Authors: Hildén Mikael
Published: June 2009

Environmental policies have to deal with nonlinear changes, discontinuities, and thresholds that may unfold with the passing of time. A recursive and adaptive approach to policy evaluation can deal with these challenges. Key characteristics of adaptive evaluations are their recursive nature, systematic exploration of multiple intervention theories, and ability to probe into new issues in close interaction with the policy development itself. ©Wiley Periodicals, Inc.
Issues of scale and monitoring status and trends in biodiversity
Authors: Kennedy Elizabeth T. , Balasubramanian Hari , Crosse William E. M.
Published: June 2009

Designing a framework that can generate data to meet multiple audience objectives must consider interactions across levels and multiple scales of interest. One solution is to define targets using global criteria such that units are discrete. This aids identification of the types of data to collect in order to enable aggregation and reporting across relevant scales. By striving to standardize measurable targets and data requirements, we improve our ability to format monitoring information and tailor indicators for different reporting and decision‐making purposes. We outline the application of a nested approach presently used by Conservation International and describe some of its advantages and limitations. © Wiley Periodicals, Inc.
Reflections on the dilemmas of conducting environmental evaluations
Authors: Preskill Hallie
Published: June 2009

The chapters in this volume set a rich context for understanding the challenges that environmental evaluators face in their everyday work. In particular, the authors highlight the need for responsive, contextual, flexible, adaptive, multidisciplinary, and mixed‐methods evaluation approaches. In this chapter, I reinforce their call and further suggest that they (1) increase their attention to developing logic models based on their theories of change, (2) continue exploring the use of complexity theory to ground their evaluations, and (3) consider reframing some evaluations to being strength‐ and asset‐based, where vibrancy, resiliency, and rebirth can be studied. Finally, in response to the authors' concern for their own development, I comment on the possibilities for evaluation capacity building and the formation of networks and communities of practice. © Wiley Periodicals, Inc.
Selectivity as well as sensitivity loss characterizes the cortical spatial frequency deficit in amblyopia
Authors: Hess Robert F. , Li Xingfeng , Mansouri Behzad , Thompson Benjamin , Hansen Bruce C.
Published: June 2009

The processing deficit in amblyopia is not restricted to just high spatial frequencies but also involves low‐medium spatial frequency processing, for suprathreshold stimuli with a broad orientational bandwidth. This is the case in all three forms of amblyopia; strabismic, anisometropic, and deprivation. Here we use both a random block design and a phase‐encoded design to ascertain (1) the extent to which fMRI activation is reduced at low‐mid spatial frequencies in different visual areas, (2) how accurately spatial frequency is mapped across the amblyopic cortex. We report a loss of function to suprathreshold low‐medium spatial frequency stimuli that involves more than just area V1, suggesting a diffuse loss in spatial frequency processing in a number of different cortical areas. An analysis of the fidelity of the spatial frequency cortical map reveals that many voxels lose their spatial frequency preference when driven by the amblyopic eye, suggesting a broader tuning for spatial frequency for neurons driven by the amblyopic eye within this low‐mid spatial frequency range. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Protein kinase C alpha‐dependent signaling mediates endometrial cancer cell growth and tumorigenesis
Authors: Haughian James M. , Reno Elaine M. , Thorne Alicia M. , Bradford Andrew P.
Published: June 2009

Endometrial cancer is the most common invasive gynecologic malignancy, yet molecular mechanisms and signaling pathways underlying its etiology and pathophysiology remain poorly characterized. We sought to define a functional role for the protein kinase C (PKC) isoform, PKCα, in an established cell model of endometrial adenocarcinoma. Ishikawa cells depleted of PKCα protein grew slower, formed fewer colonies in anchorage‐independent growth assays and exhibited impaired xenograft tumor formation in nude mice. Consistent with impaired growth, PKCα knockdown increased levels of the cyclin‐dependent kinase (CDK) inhibitors p21Cip1/WAF1 (p21) and p27Kip1 (p27). Despite the absence of functional phosphatase and tensin homolog (PTEN) protein in Ishikawa cells, PKCα knockdown reduced Akt phosphorylation at serine 473 and concomitantly inhibited phosphorylation of the Akt target, glycogen synthase kinase‐3β (GSK‐3β). PKCα knockdown also resulted in decreased basal ERK phosphorylation and attenuated ERK activation following EGF stimulation. p21 and p27 expression was not increased by treatment of Ishikawa cells with ERK and Akt inhibitors, suggesting that PKCα regulates CDK expression independently of Akt and ERK. Immunohistochemical analysis of Grade 1 endometrioid adenocarcinoma revealed aberrant PKCα expression, with foci of elevated PKCα staining, not observed in normal endometrium. These studies demonstrate a critical role for PKCα signaling in endometrial tumorigenesis by regulating expression of CDK inhibitors p21 and p27 and activation of Akt and ERK‐dependent proliferative pathways. Thus, targeting PKCα may provide novel therapeutic options in endometrial tumors. © 2009 UICC
Verprolin: A cool set of actin‐binding sites and some very HOT prolines
Authors: Munn Alan L. , Thanabalu Thirumaran
Published: June 2009

Spatiotemporal organisation of eukaryotic cells is established and maintained by the cytoskeleton, a highly dynamic and complex network of structural and signalling proteins. Many components of the cytoskeleton are functionally and structurally conserved between humans and yeast. Among these are verprolin (Vrp1p) in yeast and its human ortholog Wiskott‐Aldrich syndrome protein (WASP)‐interacting protein (WIP). Much of our understanding of the function of these proteins has come from genetic analysis in yeast. Verprolin‐deficient yeast cells exhibit defects in cytokinesis, endocytosis, and actin cytoskeleton polarisation. Verprolin binds actin, the yeast ortholog of human WASP (Las17p or Bee1p), and the yeast ortholog of human PSTPIP1 (Hof1p or Cyk2p). We propose that verprolin acts as a chaperone that by transient bimolecular interactions maintains the proper function of its partners. Verprolin‐related proteins and partners are implicated in cancer, immunodeficiency, and neurodegeneration. Therefore, elucidating how verprolin functions will have major impacts in cell biology and medicine. © 2009 IUBMB IUBMB Life 61(7): 707–712, 2009
ER stress response, peroxisome proliferation, mitochondrial unfolded protein response and Golgi stress response
Authors: Yoshida Hiderou
Published: June 2009

The endoplasmic reticulum (ER) response has been thought a cytoprotective mechanism to cope with accumulation of unfolded proteins in the ER. Recent progress has made a quantum leap revealing that ER stress response can be regarded as an autoregulatory system adjusting the ER capacity to cellular demand. This Copernican change raised a novel fundamental question in cell biology: how do cells regulate the capacity of each organelle in accordance with cellular needs? Although this fundamental question has not been fully addressed yet, research about each organelle has been advancing. The proliferation of the peroxisome is regulated by the PPARα pathway, whereas the abundance of mitochondria appears to be regulated by mitochondrial retrograde signaling and the mitochondrial unfolded protein response. The functional capacity of the Golgi apparatus may be regulated by the mechanism of the Golgi stress response. These observations strongly suggest the existence of an elaborate network of organelle autoregulation in eukaryotic cells. © 2009 IUBMB IUBMB Life 61(9): 871–879, 2009