bluuebunny/crossref_metadata_2025 huggingface dataset:
Wear characteristics of styrene butadiene rubber/natural rubber blends with varying carbon blacks by DIN abrader and mining rock surfaces
Authors: Pal Kaushik , Das Tanya , Rajasekar R. , Pal Samir K. , Das Chapal K.
Published: October 2008

In this study, nine rubber compounds were produced by varying the proportions of natural rubber (NR), styrene butadiene rubber (SBR), and four different carbon blacks. Tensile and tear properties are enhanced by the addition of intermediate super abrasion furnace (ISAF) N231, and modulus increases for the compounds containing N234 carbon blacks. The wear behavior of the prepared rubber vulcanizates against various rocks, such as, granite, shale, schist, sandstone, coal, and concrete, at 4.4 N normal load and 0.8 m/s relative sliding speed were studied in a specially fabricated experimental setup. The DIN abrasion testing results show good abrasion resistant properties of 70 phr NR and 30 phr SBR with N231 grade ISAF type carbon black. Also, moderate abrasion resistance is found in rubber compound containing 80 phr NR and 20 phr SBR with N234 grade ISAF type of carbon black. Out of the various rock types, the schist and sandstone are observed to be highly abrasive against the prepared rubber compounds. The microscopic examination of the abraded rubber surfaces has indicated the formation of longitudinal grooves against harder rocks and transverse ridges against softer rocks. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
New relations between similarity measures for vectors based on vector norms
Authors: Egghe Leo
Published: October 2008

The well‐known similarity measures Jaccard, Salton's cosine, Dice, and several related overlap measures for vectors are compared. While general relations are not possible to prove, we study these measures on the “trajectories” of the form $||\overrightarrow X || = a||\overrightarrow Y ||$, where a > 0 is a constant and ||·|| denotes the Euclidean norm of a vector. In this case, direct functional relations between these measures are proved. For Jaccard, we prove that it is a convexly increasing function of Salton's cosine measure, but always smaller than or equal to the latter, hereby explaining a curve, experimentally found by Leydesdorff. All the other measures have a linear relation with Salton's cosine, reducing even to equality, in case a = 1. Hence, for equally normed vectors (e.g., for normalized vectors) we, essentially, only have Jaccard's measure and Salton's cosine measure since all the other measures are equal to the latter.
SpamED: A spam E‐mail detection approach based on phrase similarity
Authors: Pera Maria Soledad , Ng Yiu‐Kai
Published: October 2008

E‐mail messages are unquestionably one of the most popular communication media these days. Not only are they fast and reliable but also free in general. Unfortunately, a significant number of e‐mail messages received by e‐mail users on a daily basis are spam. This fact is annoying since spam messages translate into a waste of the user's time in reviewing and deleting them. In addition, spam messages consume resources such as storage, bandwidth, and computer‐processing time. Many attempts have been made in the past to eradicate spam; however, none has proven highly effective. In this article, we propose a spam e‐mail detection approach, called SpamED, which uses the similarity of phrases in messages to detect spam. Conducted experiments not only verify that SpamED using trigrams in e‐mail messages is capable of minimizing false positives and false negatives in spam detection but it also outperforms a number of existing e‐mail filtering approaches with a 96% accuracy rate.
A global map of science based on the ISI subject categories
Authors: Leydesdorff Loet , Rafols Ismael
Published: October 2008

The decomposition of scientific literature into disciplinary and subdisciplinary structures is one of the core goals of scientometrics. How can we achieve a good decomposition? The ISI subject categories classify journals included in the Science Citation Index (SCI). The aggregated journal‐journal citation matrix contained in the Journal Citation Reports can be aggregated on the basis of these categories. This leads to an asymmetrical matrix (citing versus cited) that is much more densely populated than the underlying matrix at the journal level. Exploratory factor analysis of the matrix of subject categories suggests a 14‐factor solution. This solution could be interpreted as the disciplinary structure of science. The nested maps of science (corresponding to 14 factors, 172 categories, and 6,164 journals) are online at http://www.leydesdorff.net/map06. Presumably, inaccuracies in the attribution of journals to the ISI subject categories average out so that the factor analysis reveals the main structures. The mapping of science could, therefore, be comprehensive and reliable on a large scale albeit imprecise in terms of the attribution of journals to the ISI subject categories.
Shifting of the distribution of aromatic monomer‐units in polyhydroxyalkanoic acid to longer units by salicylic acid in Pseudomonas fluorescens BM07 grown with mixtures of fructose and 11‐phenoxyundecanoic acid
Authors: Choi Mun Hwan , Xu Ju , Rho Jong Kook , Shim Ji Hoon , Yoon Sung Chul
Published: October 2008

Medium‐chain‐length‐polyhydroxyalkanoic acids (MCL‐PHAs) formed in Pseudomonas spp. have a rather broad distribution of monomer‐units whose precursors are supplied via β‐oxidation degradation of MCL fatty acids fed as the carbon source and/or via PhaG enzyme catalyzing the acyl‐group transfer from 3‐hydroxyacyl‐ACPs derived from acetyl‐CoA to coenzyme A. It was found that salicylic acid (SA), in a concentration dependent manner, suppressed the accumulation of PHA in Pseudomonas fluorescens BM07 from fructose as well as shifted the distribution of monomer‐units derived from a MCL fatty acid co‐added as carbon source (e.g., 11‐phenoxyundecanoic acid (11‐POU)) to longer monomer‐units. Both SA and acrylic acid were found to induce high accumulations of 3‐ketohexanoic acid in BM07 wild‐type cells grown with n‐hexanoic acid as well as to inhibit the formation of acetyl‐CoA from acetoacetyl‐CoA by BM07 cell extract, suggesting that 3‐ketoacyl‐CoA thiolase is their common β‐oxidation target. The structural motif of acrylic acid present in the molecular structure of SA may self‐explain the similar actions of the two inhibitors. A comparison of monomer modulation between BM07 wild‐type and ΔphaG mutant cells grown on the mixtures of fructose and 11‐POU revealed that both PhaG and β‐oxidation inhibitor may play a critical role in the synthesis of PHA with longer side‐chain ω‐functional substitutions. Biotechnol. Bioeng. 2009;102: 1209–1221. © 2008 Wiley Periodicals, Inc.
Maintenance and growth requirements in the metabolism of Debaryomyces hansenii performing xylose‐to‐xylitol bioconversion in corncob hemicellulose hydrolyzate
Authors: Rivas Beatriz , Torre Paolo , Domínguez José Manuel , Converti Attilio
Published: October 2008

In order to improve the biotechnological production of xylitol, the metabolism of Debaryomyces hansenii NRRL Y‐7426 in corncob hemicellulose hydrolyzate has been investigated under different conditions, where either maintenance or growth requirements predominated. For this purpose, the experimental results of two sets of batch bioconversions carried out alternatively varying the starting xylose concentration in the hydrolyzate (65.6 ≤ S0 ≤ 154.7 g L−1) or the initial biomass level (3.0 ≤ X0 ≤ 54.6 gDM L−1) were used to fit a metabolic model consisting of carbon material and ATP balances based on five main activities, namely fermentative assimilation of pentoses, semi‐aerobic pentose‐to‐pentitol bioconversion, biomass growth on pentoses, catabolic oxidation of pentoses, and acetic acid and NADH regeneration by the electron transport system. Such an approach allowed separately evaluating the main bioenergetic constants of this microbial system, that is, the specific rates of ATP and xylose consumption due to maintenance (mATP = 21.0 mmolATP C−molDM−1h−1; mXyl = 6.5 C‐mmolXyl C−molDM−1h−1) and the true yields of biomass on ATP (YATPmax = 0.83 C‐molDM molATP−1) and on xylose (YXylmax = 0.93 C‐molDM C‐molXyl−1). The results of this study highlighted that the system, at very high S0 and X0 values, dramatically increased its energy requirements for cell maintenance, owing to the occurrence of stressing conditions. In particular, for S0 > 130 g L−1, these activities required an ATP consumption of about 2.1 molATP L−1, that is, a value about seven‐ to eightfold that observed at low substrate concentration. Such a condition led to an increase in the fraction of ATP addressed to cell maintenance from 47% to 81%. On the other hand, the very high percentage of ATP addressed to maintenance (>96%) at very high cell concentration (X0 ≥ 25 gDM L−1) was likely due to the insufficient substrate to sustain the growth. Biotechnol. Bioeng. 2009;102: 1062–1073. © 2008 Wiley Periodicals, Inc.
High‐level bacterial cellulase accumulation in chloroplast‐transformed tobacco mediated by downstream box fusions
Authors: Gray Benjamin N. , Ahner Beth A. , Hanson Maureen R.
Published: October 2008

The Thermobifida fusca cel6A gene encoding an endoglucanase was fused to three different downstream box (DB) regions to generate cel6A genes with 14 amino acid fusions. The DB‐Cel6A fusions were inserted into the tobacco (Nicotiana tabacum cv. Samsun) chloroplast genome for protein expression. Accumulation of Cel6A protein in transformed tobacco leaves varied over approximately two orders of magnitude, dependent on the identity of the DB region fused to the cel6A open reading frame (ORF). Additionally, the DB region fused to the cel6A ORF affected the accumulation of Cel6A protein in aging leaves, with the most effective DB regions allowing for high level accumulation of Cel6A protein in young, mature, and old leaves, while Cel6A protein accumulation decreased with leaf age when less effective DB regions were fused to the cel6A ORF. In the most highly expressed DB‐Cel6A construct, enzymatically active Cel6A protein accumulated at up to 10.7% of total soluble leaf protein (%TSP). The strategy used for high‐level endoglucanase expression may be useful for expression of other cellulolytic enzymes in chloroplasts, ultimately leading to cost‐effective heterologous enzyme production for cellulosic ethanol using transplastomic plants. Biotechnol. Bioeng. 2009;102: 1045–1054. © 2008 Wiley Periodicals, Inc.
Tricalcium phosphate nanoparticles enable rapid purification, increase transduction kinetics, and modify the tropism of mammalian viruses
Authors: Dreesen Imke A.J. , Lüchinger Norman A. , Stark Wendelin J. , Fussenegger Martin
Published: October 2008

Adenoviral, adeno‐associated viral, and retroviral particles are chosen as gene delivery shuttles in more than 50% of all gene therapy clinical trials. Bulk availability of clinical‐grade viral particles and their efficiency to transduce the therapeutic cargo into specific target cells remain the most critical bottlenecks in gene therapy applications to date. Capitalizing on the flame‐spray technology for the reproducible economic large‐scale production of amorphous tricalcium phosphate nanoparticulate powders (ATCP), we designed a scalable ready‐to‐use gravity‐flow column set‐up for the straightforward concentration and purification of transgenic adenoviral, adeno‐associated viral, and lentiviral particles. Specific elution buffers enabled rapid release of viral particles from the ATCP matrix of the column and provided high‐titer virus preparations in an unsurpassed period of time. The interaction of ATCP with adenoviral, adeno‐associated viral, and lentiviral particles in solution increased the transduction kinetics of several mammalian cell lines in culture. The nanoparticles were also able to modify the tropism of murine leukemia virus (MLV) towards transduction of human cells. Based on these findings, we believe that the use of flame‐spray tricalcium phosphate nanoparticles will lead to important progress in the development of future gene therapy initiatives. Biotechnol. Bioeng. 2009;102: 1197–1208. © 2008 Wiley Periodicals, Inc.
A study of monoclonal antibody‐producing CHO cell lines: What makes a stable high producer?
Authors: Chusainow Janet , Yang Yuan Sheng , Yeo Jessna H.M. , Toh Poh Choo , Asvadi Parisa , Wong Niki S.C. , Yap Miranda G.S.
Published: October 2008

Generating stable, high‐producing cell lines for recombinant protein production requires an understanding of the potential limitations in the cellular machinery for protein expression. In order to increase our understanding of what makes a stable high producer, we have generated a panel of 17 recombinant monoclonal antibody expressing Chinese hamster ovary subclones (CHO‐mAb) with specific productivities ranging between 3 and 75 pg cell−1 day−1 using the dihydrofolate reductase (dhfr) expression system and compared the molecular features of these high‐ and low‐producer clones. The relative heavy chain (HC) and light chain (LC) transgene copy numbers and mRNA levels were determined using real‐time quantitative PCR (RT qPCR). We observed that not only higher transgene copy numbers and mRNA levels of both HC and LC were characteristic for the high‐producer clones as compared to the low‐producer clones but also a more favorable HC to LC transgene copy numbers ratio. By studying the long‐term stability of the CHO‐mAb subclones in the absence of methotrexate (MTX) selective pressure over 36 passages we observed a 35–92% decrease in volumetric productivity, primarily caused by a significant decrease in HC and LC mRNA levels with little change in the transgene copy numbers. Using Southern blot hybridization we analyzed the HC and LC transgene integration patterns in the host chromosome and their changes in course of gene amplification and long‐term culturing. We observed that MTX‐induced gene amplification caused chromosomal rearrangements resulting in clonal variability in regards to growth, productivity, and stability. No further obvious DNA rearrangements occurred during long‐term culturing in the absence of MTX, indicating that other mechanisms were responsible for the decreased transcription efficiency. Our results implicate that the amplified transgene sequences were arranged in tandem repeats potentially triggering repeat‐induced gene silencing. We hypothesize that the decline in transgene mRNA levels upon long‐term culturing without MTX was mainly caused by transgene silencing consequently leading to a loss in mAb productivity. The exact molecular mechanisms causing production instability are not yet fully understood. The herein described extensive characterization studies could help understand the limitations to high‐level, stable recombinant protein production and find ways to improving and accelerating the process for high‐producer cell line generation and selection. Biotechnol. Bioeng. 2009;102: 1182–1196. © 2008 Wiley Periodicals, Inc.
Role of surfactant on the proteolysis of aqueous bovine serum albumin
Authors: Porcel E.M. Rodriguez , Foose L.L. , Svitova T.F. , Blanch H.W. , Prausnitz J.M. , Radke C.J.
Published: October 2008

Nonionic and ionic surfactants diminish the initial rate of proteolysis of aqueous bovine serum albumin (BSA) by subtilisin Carlsberg. Surfactants studied include: nonionic tetraethylene glycol monododecyl ether (C12E4); anionic sodium dodecyl sulfate (SDS), anionic sodium dodecylbenzenesulfonate (SDBS), and cationic dodecyltrimethylamonium bromide (DTAB). Kinetic data are obtained using fluorescence emission. Special attention is given to enzyme kinetic specificity determined by fitting initial‐rate data to the Michaelis–Menten model. All surfactants reduce the rate of proteolysis, most strongly at concentrations near and above the critical micelle concentration (CMC). Circular dichroism (CD), tryptophan/tyrosine fluorescence spectra, and tryptophan fluorescence thermograms indicate that BSA partially unfolds at ionic surfactant concentrations near and above the CMC. Changes in BSA conformation are less apparent at ionic surfactant concentrations below the CMC and for the nonionic surfactant C12E4. Subtilisin Carlsberg activity against the polypeptide, succinyl‐Ala‐Ala‐Pro‐Phe‐p‐nitroanilide, decreased due to enzyme–surfactant interaction. At the concentrations and time frames studied, there was no enzyme autolysis. Importantly, aqueous proteolysis rates are significantly reduced at high surfactant concentrations where protein–micellar–surfactant aggregates occur. To explain the negative effect of surfactant on subtilisin Carlsberg proteolytic activity against BSA, we propose that micelle/protein complexes hinder enzyme access. Biotechnol. Bioeng. 2009;102: 1330–1341. © 2008 Wiley Periodicals, Inc.
The kinetics of cellulose dissolution in sodium hydroxide solution at low temperatures
Authors: Wang Ying , Deng Yulin
Published: October 2008

The dissolution kinetics of cellulose in sodium hydroxide in the presence and absence of urea at low temperature was studied. High molecular weight cotton linter with degree of polymerization of 850 was used for dissolution study. The cotton linter was separated from the dissolution slurry at different dissolution times, and the change of the crystal structure of cotton linter was characterized by Powder X‐Ray Diffraction. The rate of decrystallization of cellulose was obtained and the activation energy for cellulose decrystallization in sodium hydroxide solution was derived using Eyring equation. The effect of urea additive was discussed. Biotechnol. Bioeng. 2009;102: 1398–1405. © 2008 Wiley Periodicals, Inc.
DBT degradation enhancement by decorating Rhodococcus erythropolis IGST8 with magnetic Fe3O4 nanoparticles
Authors: Ansari F. , Grigoriev P. , Libor S. , Tothill I.E. , Ramsden J.J.
Published: October 2008

Biodesulfurization (BDS) of dibenzothiophene (DBT) was carried out by Rhodococcus erythropolis IGST8 decorated with magnetic Fe3O4 nanoparticles, synthesized in‐house by a chemical method, with an average size of 45–50 nm, in order to facilitate the post‐reaction separation of the bacteria from the reaction mixture. Scanning electron microscopy (SEM) showed that the magnetic nanoparticles substantially coated the surfaces of the bacteria. It was found that the decorated cells had a 56% higher DBT desulfurization activity in basic salt medium (BSM) compared to the nondecorated cells. We propose that this is due to permeabilization of the bacterial membrane, facilitating the entry and exit of reactant and product, respectively. Model experiments with black lipid membranes (BLM) demonstrated that the nanoparticles indeed enhance membrane permeability. Biotechnol. Bioeng. 2009;102: 1505–1512. © 2008 Wiley Periodicals, Inc.
Disulfide Bond Creates a Small Connecting Loop in Aminoxy Peptide Backbone
Authors: Yang Dan , Liu Guo‐Jun , Jiao Zhi‐Gang , Zhang Dan‐Wei , Luo Zheng , Song Ke‐Sheng , Chen Min‐Qin
Published: October 2008

Disulfide‐bond formation between the side chains of cysteine–cysteine pairs is often critical to the folding behavior, stability, and functionality of proteins. In this paper, we report that sulfur atoms can be introduced into the amide groups of aminoxy peptides to form a novel type of disulfide bridge, which creates a connecting loop in the peptide backbone.
Polymorphic Coordination Networks Responsive to CO2, Moisture, and Thermal Stimuli: Porous Cobalt(II) and Zinc(II) Fluoropyrimidinolates
Authors: Galli Simona , Masciocchi Norberto , Tagliabue Giulia , Sironi Angelo , Navarro Jorge A. R. , Salas Juan M. , Mendez‐Liñan Laura , Domingo Maria , Perez‐Mendoza Manuel , Barea Elisa
Published: October 2008

The novel porous [{M(F‐pymo)2}n]⋅2.5n H2O coordination networks (M=Co, Zn; F‐pymo=5‐fluoropyrimidin‐2‐olate), possessing sodalitic topology, have been synthesised and structurally characterised by means of powder diffraction methods. Thermodiffractometry demonstrated their plasticity: when heated up to 363 K, they reversibly transform into three‐dimensional dehydrated [{M(F‐pymo)2}n] species, with significantly different lattice parameters. Further heating induces irreversible polymorphic transformations into layered phases, in which the original MN4 coordination sphere changes into an MN3O one. A mixed‐metal phase, [{CoxZn1−x(F‐pymo)2}n]⋅2.5n H2O, was also prepared, showing that zinc is preferentially inserted, when starting from a Co/Zn reagent ratio of 1:1. The solid–gas adsorption properties of the anhydrous 3D frameworks have been explored towards N2, H2 (77 K) and CH4, CO2 (273 K). These results show that these materials permit the diffusion of CO2 molecules only. Remarkably, the CO2 adsorption process for the [{Co(F‐pymo)2}n] network proceeds in two steps: the first step takes place at low pressures (<600 kPa) and the second one above a threshold pressure of 600 kPa. By contrast, the [{Zn(F‐pymo)2}n] network only permits CO2 diffusion by applying pressures above 900 kPa. This type of behaviour is typical of porous networks with gated channels. The high CO2 selectivity of these systems over the rest of the essayed probe gases is explained in terms of flexibility and polarity of the porous network. Finally, the magnetic studies on the CoII systems reveal that the as synthesised [{Co(F‐pymo)2}n]⋅2.5n H2O material behaves as an antiferromagnet with a TN of about 29 K. At variance, the [{Co(F‐pymo)2}n] layered phase shows an unusually weak ferromagnetic ordering below 17 K, arising from a spin‐canting phenomenon.
Neuroarchitecture of the central complex of the desert locust: Intrinsic and columnar neurons
Authors: Heinze Stanley , Homberg Uwe
Published: October 2008

The central complex is a group of neuropils in the center of the insect brain. It consists of four major subunits: the upper and lower divisions of the central body (CBU, CBL), the protocerebral bridge (PB), and the paired noduli. A distinctive feature of the central complex is a modular architecture characterized by rows of 16 columns, intersected in the central body by stacks of layers. Evidence from locusts suggests that the central complex plays a major role in sky compass orientation. To understand signal processing in this brain area further, we have analyzed the morphologies of columnar neurons of the central complex of the locust Schistocerca gregaria. Intracellular dye fills revealed 21 types of columnar neurons that connect columns of different subunits, three types of pontine neurons linking pairs of columns within the CBU, and one amacrine cell. Most neurons appeared to be part of isomorphic sets with cell type‐specific heterolateral projection patterns. Evaluation of arborization areas and neuron polarity suggests that these neurons are either intrinsic to the central complex or provide output to the lateral accessory lobes (LALs) or anterior lip region. No direct connections were found between the CBU and CBL. Instead, neurons of either subdivision were connected with the PB, but projected to non‐overlapping regions in the LALs and to different layers of the noduli. This study provides novel insights into the functional organization of the central complex, especially with respect to its likely role in right‐left signal matching and decision making. J. Comp. Neurol. 511:454–478, 2008. © 2008 Wiley‐Liss, Inc.
Fluorescent labeling of proteins in living cells using the FKBP12 (F36V) tag
Authors: Robers Matt , Pinson Patrick , Leong Louis , Batchelor Robert H. , Gee Kyle R. , Machleidt Thomas
Published: October 2008

Over the past decade live cell imaging has become a key technology to monitor and understand the dynamic behavior of proteins in the physiological context of living cells. The visualization of a protein of interest is most commonly achieved by genetically fusing it to green fluorescent protein (GFP) or one of it variants. Considerable effort has been made to develop alternative methods of protein labeling to overcome the intrinsic limitations of fluorescent proteins. In this report we show the optimization of a live cell labeling technology based on the use of a mutant form of FKBP12 (FKBP12(F36V)) in combination with a synthetic high affinity ligand (SLF') that specifically binds to this mutant. It had been previously shown that the use of a fluorescein‐conjugated form of SLF' (5′‐fluorescein‐SLF') allowed the labeling of proteins genetically fused to FKBP‐F36V in living cells. Here we describe the identification of novel fluorescent SLF'dye conjugates that allow specific labeling of FKBP12(F36V) fusion proteins in living cells. To further increase the versatility of this technology we developed a number of technical improvements. We implemented the use of pluronics during the labeling process to facilitate the uptake of the SLF'‐dye conjugates and the use suppression dyes to reduce background signal. Furthermore, the time and dose dependency of labeling was investigated in order to determine optimal labeling conditions. Finally, the specificity of the FKBP12(F36V) labeling technology was extensively validated by morphological analysis using a diverse set of FKBP12(F36V) fusions proteins. In addition we show a number of different application examples, such as translocation assays, the generation of biosensors, and multiplex labeling in combination with different labeling technologies, such as FlAsH or GFP. In summary we show that the FKBP12(F36V)/SLF' labeling technology has a broad range of applications and should prove useful for the study of protein function in living cells. © 2008 International Society for Advancement of Cytometry
Policy profile: a framework for the classification, prioritization and analysis of research for European environmental regulators
Authors: Gardner M. J. , Hunt D. T. E. , Gardner S. , Shackell K.
Published: October 2008

The SKEP ERA‐NET (Scientific Knowledge for Environmental Protection) is a consortium of European public sector organizations funding environmental research. The network is funded by the European Commission's Sixth Framework Programme (FP6). The aim of the network is to facilitate the improvement of science‐into‐policy processes and to support evidence‐based regulation. This paper contains a description of the categorization and review of current environmental research within the network. It also illustrates how a comparison of current activities combined with perceptions of future needs can provide an analysis of research gaps. The importance of an assessment of relative research costs in such a gap analysis is emphasized. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.
“This story is right on”: The impact of regulatory fit on narrative engagement and persuasion
Authors: Vaughn Leigh Ann , Hesse Sarah J. , Petkova Zhivka , Trudeau Lindsay
Published: October 2008

When people read a story, feelings of rightness from regulatory fit (consistency between regulatory state and strategic means) could suggest that the story is “right on” relative to feelings of wrongness from regulatory nonfit. Under these conditions, individuals who are experiencing feelings of rightness should engage more with the narrative and be more persuaded by its implicit messages. Results from two experiments supported these hypotheses. Participants in Experiment 1 were more mentally engaged (transported) by the story when they experienced regulatory fit. We replicated this effect in Experiment 2 and extended it to endorsement of story‐consistent beliefs, an indicator of persuasion via narratives. Additionally, we found that drawing participants' attention to an earlier event as a source of feelings of rightness eliminated the regulatory fit effects on transportation and persuasion, suggesting attribution of feelings of regulatory fit/nonfit to the plausibility of the narrative world. Copyright © 2008 John Wiley & Sons, Ltd.
Interpersonal relationships moderate the effect of faces on person judgments
Authors: Tuk Mirjam A. , Verlegh Peeter W. J. , Smidts Ale , Wigboldus Daniel H. J.
Published: October 2008

Previous research suggests that people form impressions of others based on their facial appearance in a very fast and automatic manner, and this especially holds for trustworthiness. However, as yet, this process has been investigated mostly in a social vacuum without taking interpersonal factors into account. In the current research, we demonstrate that both the relationship context that is salient at the moment of an interaction and the performed behavior are important moderators of the impact of facial cues on impression formation. It is shown that, when the behavior of a person we encounter is ambiguous in terms of trustworthiness, the relationship most salient at that moment is of crucial impact on whether and how we incorporate facial cues communicating (un)trustworthiness in our final evaluations. Ironically, this can result in less positive evaluations of interaction partners with a trustworthy face compared to interaction partners with an untrustworthy face. Implications for research on facial characteristics, trust, and relationship theories are discussed. Copyright © 2008 John Wiley & Sons, Ltd.
European norms and equations for a two dimensional presentation of values as measured with Schwartz's 21‐item portrait values questionnaire
Authors: Verkasalo Markku , Lönnqvist Jan‐Erik , Lipsanen Jari , Helkama Klaus
Published: October 2008

The present study utilizes European Social Survey (ESS) data to introduce European norms and equations for computation of the Self‐Transcendence—Self‐Enhancement and Conservation—Openness to Change value dimensions, as measured with the 21‐item Portrait Values Questionnaire (PVQ). Our analysis of ESS round 1 and 2 data suggest that the two‐dimensional structure and the equations based on this structure are extremely robust. Presenting the two value dimensions besides the 10 basic values offers the advantages of (a) heightened reliability, (b) control of response tendency, and (c) possibility to present results in two‐dimensional space. Copyright © 2008 John Wiley & Sons, Ltd.
Comparative epigenomics of human and mouse mammary tumors
Authors: Demircan Berna , Dyer Lisa M. , Gerace Mallory , Lobenhofer Edward K. , Robertson Keith D. , Brown Kevin D.
Published: October 2008

Gene silencing by aberrant epigenetic chromatin alteration is a well‐recognized event contributing to tumorigenesis. Although genetically engineered tumor‐prone mouse models have proven a powerful tool in understanding many aspects of carcinogenesis, to date few studies have focused on epigenetic alterations in mouse tumors. To uncover epigenetically silenced tumor suppressor genes (TSGs) in mouse mammary tumor cells, we conducted initial genome‐wide screening by combining the treatment of cultured cells with the DNA demethylating drug 5‐aza‐2′‐deoxycytidine (5‐azadC) and the histone deacetylase inhibitor trichostatin A (TSA) with expression microarray. By conducting this initial screen on EMT6 cells and applying protein function and genomic structure criteria to genes identified as upregulated in response to 5‐azadC/TSA, we were able to identify two characterized breast cancer TSGs (Timp3 and Rprm) and four putative TSGs (Atp1B2, Dusp2, FoxJ1 and Smpd3) silenced in this line. By testing a panel of 10 mouse mammary tumor lines, we determined that each of these genes is commonly hypermethylated, albeit with varying frequency. Furthermore, by examining a panel of human breast tumor lines and primary tumors we observed that the human orthologs of ATP1B2, FOXJ1 and SMPD3 are aberrantly hypermethylated in the human disease whereas DUSP2 was not hypermethylated in primary breast tumors. Finally, we examined hypermethylation of several genes targeted for epigenetic silencing in human breast tumors in our panel of 10 mouse mammary tumor lines. We observed that the orthologs of Cdh1, RarB, Gstp1, RassF1 genes were hypermethylated, whereas neither Dapk1 nor Wif1 were aberrantly methylated in this panel of mouse tumor lines. From this study, we conclude that there is significant, but not absolute, overlap in the epigenome of human and mouse mammary tumors. © 2008 Wiley‐Liss, Inc.
2‐Arachidonoylglycerol elicits neuroprotective effects on excitotoxically lesioned dentate gyrus granule cells via abnormal‐cannabidiol‐sensitive receptors on microglial cells
Authors: Kreutz Susanne , Koch Marco , Böttger Charlotte , Ghadban Chalid , Korf Horst‐Werner , Dehghani Faramarz
Published: October 2008

Endocannabinoids like 2‐arachidonoylglycerol (2‐AG) exert neuroprotective effects after brain injuries. According to current concepts, these neuroprotective effects are due to interactions between 2‐AG and cannabinoid (CB)1 receptors on neurons. Moreover, 2‐AG modulates migration and proliferation of microglial cells which are rapidly activated after brain lesion. This effect is mediated via CB2‐ and abnormal‐cannabidiol (abn‐CBD)‐sensitive receptors. In the present study, we investigated whether the abn‐CBD‐sensitive receptor on microglial cells contributes to 2‐AG‐mediated neuroprotection in organotypic hippocampal slice cultures (OHSCs) after excitotoxic lesion induced by NMDA (50 μM) application for 4 h. This lesion caused neuronal damage and accumulation of microglial cells within the granule cell layer. To analyze the role of abn‐CBD‐sensitive receptors for neuroprotection and microglial cell accumulation, two agonists of the abn‐CBD‐sensitive receptor, abn‐CBD or 2‐AG, two antagonists, 1,3‐dimethoxy‐5‐methyl‐2‐[(1R,6R)‐3‐methyl‐6‐(1‐methylethenyl)‐2‐cyclohexen1‐yl]‐benzene (O‐1918) or cannabidiol (CBD), and the CB1 receptor antagonist AM251, were applied to NMDA‐lesioned OHSC. Propidium iodide (PI) labeling was used as a marker of degenerating neurons and isolectin B4 (IB4) as a marker of microglial cells. Application of both, abn‐CBD or 2‐AG to lesioned OHSC significantly decreased the number of IB microglial cells and PI+ neurons in the dentate gyrus. In contrast to AM251, application of O‐1918 or CBD antagonized these effects. When microglial cells were depleted by preincubation of OHSC with the bisphosphonate clodronate (100 μg/mL) for 5 days before excitotoxic lesion, 2‐AG and abn‐CBD lost their neuroprotective effects. We therefore propose that the endocannabinoid 2‐AG exerts its neuroprotective effects via activation of abn‐CBD‐sensitive receptors on microglial cells. © 2008 Wiley‐Liss, Inc.
Depression of parallel and climbing fiber transmission to Bergmann glia is input specific and correlates with increased precision of synaptic transmission
Authors: Balakrishnan Saju , Bellamy Tomas C.
Published: October 2008

In the cerebellar cortex, Bergmann glia enclose the synapses of both parallel and climbing fiber inputs to the Purkinje neuron. The glia express Ca2+‐permeable AMPA receptors, and the GLAST and GLT‐1 classes of glutamate transporter, which are activated by glutamate released during synaptic transmission. We have previously reported that parallel fiber to Bergmann glial transmission in rat cerebellar slices exhibits a form of frequency‐dependent plasticity, namely long‐term depression, following repetitive stimulation at 0.1–1 Hz. Here, we report that this form of plasticity is also present at the climbing fiber input, that climbing and parallel fibers can be depressed independently, that discrete parallel fiber inputs can also be depressed independently, and that depression is maintained when a distributed array of parallel fibers are stimulated (in contrast to several forms of synaptic plasticity at the Purkinje neuron). Depression of glutamate transporter currents does not correlate with a decrease in the stringency with which Purkinje neuron synapses are isolated. Rather, postsynaptic currents in Purkinje neurons decay more rapidly and perisynaptic metabotropic glutamate receptors are activated less effectively after stimulation at 0.2 and 1 Hz, suggesting that depression arises from a decrease in extrasynaptic glutamate concentration and not from impairment of glutamate clearance in and around the synapse. These results indicate that neuron‐glial plasticity is activity dependent, input specific and does not require spillover between adjacent synapses to manifest. They also argue against a withdrawal of the glial sheath from synaptic regions as the putative mechanism of plasticity. © 2008 Wiley‐Liss, Inc.
Quantitative analysis of mitotic Olig2 cells in adult human brain and gliomas: Implications for glioma histogenesis and biology
Authors: Rhee Wootack , Ray Sutapa , Yokoo Hideaki , Hoane Megan E. , Lee Chong C. , Mikheev Andrei M. , Horner Philip J. , Rostomily Robert C.
Published: October 2008

The capacity of adult human glial progenitor cells (AGPs), to proliferate and undergo multipotent differentiation, positions them as ideal candidate cells of origin for human gliomas. To investigate this potential role we identified AGPs as mitotically active Olig2 cells in nonneoplastic adult human brain and gliomas. We conservatively estimated that one in 5,000 human temporal lobe neocortical gray or subcortical white matter cells is mitotic. Extrapolating from a mean Olig2/Mib‐1 labeling index (LI) of 52% and total cell number of 100 billion, we estimated the overall prevalence of mitotic Olig2 AGPs in nonneoplastic human brain parenchyma at 10 million. These data identify a large reservoir of Olig2 AGPs which could be potential targets for human gliomagenesis. The vast majority of mitotic cells in Grade II and Grade III gliomas of all histologic subtypes expressed Olig2 (mean LI 75%) but rarely S100B (LI 0.6%), identifying the Olig2 cell as a distinct contributor to the proliferating cell population of human gliomas of both oligodendroglial and astrocytic lineages. In the most malignant Grade IV glioma, or glioblastoma multiforme (GBM), the prevalence of Olig2/Mib‐1 cells was significantly decreased (24.5%). The significantly lower Olig2/Mib‐1 LI in GBMs suggests that a decrease in the prevalence of Olig2 cells to the total mitotic cell pool accompanies increasing malignancy. The novel framework provided by this quantitative and comparative analysis supports future studies to examine the histogenetic role of Olig2 AGPs in adult gliomas, their potential contribution to the tumor stroma and the molecular role of Olig2 in glioma pathogenesis. © 2008 Wiley‐Liss, Inc.
The giant protein AHNAK involved in morphogenesis and laminin substrate adhesion of myelinating Schwann cells
Authors: Salim Claudio , Boxberg Ysander V. , Alterio Jeanine , Féréol Sophie , Nothias Fatiha
Published: October 2008

Within the nervous system, expression of the intriguing giant protein AHNAK had been reported so far only for blood–brain barrier forming vascular endothelium. In a screen for genes upregulated after spinal cord injury, we recently identified ahnak as being highly expressed by non‐neuronal cells invading the lesion, delimiting the interior surface of cystic cavities in front of barrier‐forming astrocytes. Here, we show for the first time that AHNAK is constitutively expressed in peripheral nervous system, notably by myelinating Schwann cells (SCs), in which we investigated its function. During sciatic nerve development, AHNAK is redistributed from adaxonal toward abaxonal SC compartments in contact with basement membrane. AHNAK labeling on myelinated fibers from adult nerve delineates the so‐called “Cajal bands,” constituting the residual peripheral SC cytoplasm. Its distribution pattern is complementary to that of periaxin, known to be involved in the myelination process. In vitro, nonconfluent cultured primary SCs seeded on laminin express high levels of AHNAK concentrated in their processes, whereas at confluence, AHNAK is downregulated together with laminin receptor dystroglycan. AHNAK silencing by siRNA interference affects SC morphology and laminin‐substrate attachment, as well as expression and distribution of dystroglycan. Thus, our results clearly show the implication of AHNAK in SC adhesion to laminin, probably via targeting of the dystroglycan‐associated receptor complex. These findings are of high interest regarding the importance of SC‐basal lamina interactions for myelination and myelin maintenance, and open up new perspectives for investigations of the molecular mechanisms underlying demyelinating neuropathies. © 2008 Wiley‐Liss, Inc.
Oligodendrocytes and myelination: The role of iron
Authors: Todorich Bozho , Pasquini Juana M. , Garcia Corina I. , Paez Pablo M. , Connor James R.
Published: October 2008

Iron is an essential trophic factor that is required for oxygen consumption and ATP production. Thus it plays a key role in vital cell functions. Although the brain has a relatively high rate of oxygen consumption compared to other organs, oligodendrocytes are the principal cells in the CNS that stain for iron under normal conditions. The importance of iron in myelin production has been demonstrated by studies showing that decreased availability of iron in the diet is associated with hypomyelination. The timing of iron delivery to oligodendrocytes during development is also important because hypomyelination and the associated neurological sequelae persist long after the systemic iron deficiency has been corrected. Therefore, identifying the molecular roles of iron in oligodendrocyte development and myelin production, and the mechanisms and timing of iron acquisitions are important prerequisites to developing effective therapies for dysmyelinating disorders. It is the purpose of this review to give a comprehensive overview of the existing literature on role of iron in oligodendrocytes and the mechanisms of iron acquisition and intracellular handling. © 2008 Wiley‐Liss, Inc.
ATP induces long‐term potentiation of C‐fiber‐evoked field potentials in spinal dorsal horn: The roles of P2X4 receptors and p38 MAPK in microglia
Authors: Gong Qing‐Juan , Li Yu‐Ying , Xin Wen‐Jun , Zang Ying , Ren Wen‐Jie , Wei Xu‐Hong , Li Yong‐Yong , Zhang Tong , Liu Xian‐Guo
Published: October 2008

Many studies have shown that adenosine triphosphate (ATP), as a neurotransmitter, is involved in plastic changes of synaptic transmission in central nervous system. In the present study, we tested whether extracellular ATP can induce long‐term potentiation (LTP) of C‐fiber‐evoked field potentials in spinal dorsal horn. The results showed the following: (1) ATP at a concentration of 0.3 mM induced spinal LTP of C‐fiber‐evoked field potentials, lasting for at least 5 h; (2) spinal application of 2′,3′‐O‐(2,4,6‐trinitrophenyl)adenosine‐5‐triphosphate (TNP‐ATP; an antagonist of P2X1–4 receptors), but not pyridoxal‐phosphate‐6‐azophenyl‐2′,4′‐disulphonic acid (PPADS; an antagonist of P2X1,2,3,5,7 receptors), 30 min before ATP blocked ATP‐induced LTP, indicating that ATP may induce spinal LTP by activation of P2X4 receptors; (3) at 60 min after LTP induction the level of phospho‐p38 mitogen‐activated protein kinase (p‐p38 MAPK) was significantly elevated and at 180 min after LTP the number of P2X4 receptors increased significantly; both p‐p38 and P2X4 receptors were exclusively co‐located with the microglia marker, but not with neuronal or astrocyte marker; (4) spinal application of TNP‐ATP but not PPADS prevented p38 activation; (5) spinal application of SB203580, a p38 MAPK inhibitor, prevented both spinal LTP and the upregulation of P2X4 receptors. The results suggested that ATP may activate p38 MAPK by binding to intrinsic P2X4 receptors in microglia, and subsequently enhance the expression of P2X4 receptors, contributing to spinal LTP. © 2008 Wiley‐Liss, Inc.
Flow cytometric isolation and clonal identification of self-renewing bipotent hepatic progenitor cells in adult mouse liver
Authors: Suzuki Atsushi , Sekiya Sayaka , Onishi Makiko , Oshima Naoko , Kiyonari Hiroshi , Nakauchi Hiromitsu , Taniguchi Hideki
Published: October 2008

The adult liver progenitor cells appear in response to several types of pathological liver injury, especially when hepatocyte replication is blocked. These cells are histologically identified as cells that express cholangiocyte markers and proliferate in the portal area of the hepatic lobule. Although these cells play an important role in liver regeneration, the precise characterization that determines these cells as self-renewing bipotent primitive hepatic cells remains to be shown. Here we attempted to isolate cells that express a cholangiocyte marker from the adult mouse liver and perform single cell-based analysis to examine precisely bilineage differentiation potential and self-renewing capability of these cells. Based on the results of microarray analysis and immunohistochemistry, we used an antibody against CD133 and isolate CD133+ cells via flow cytometry. We then cultured and propagated isolated cells in a single cell culture condition and examined their potential for proliferation and differentiation

in vitro

and

in vivo

. Isolated cells that could form large colonies (LCs) in culture gave rise to both hepatocytes and cholangiocytes as descendants, while maintaining undifferentiated cells by self-renewing cell divisions. The clonogenic progeny of an LC-forming cell is capable of reconstituting hepatic tissues

in vivo

by differentiating into fully functional hepatocytes. Moreover, the deletion of

p53

in isolated LC-forming cells resulted in the formation of tumors with some characteristics of hepatocellular carcinoma and cholangiocarcinoma upon subcutaneous injection into immunodeficient mutant mice. These data provide evidence for the stem cell-like capacity of isolated and clonally cultured CD133+ LC-forming cells.

Conclusion:

Our method for prospectively isolating hepatic progenitor cells from the adult mouse liver will facilitate study of their roles in liver regeneration and carcinogenesis. (Hepatology 2008;48:1964-1978.)
Great toe transplant versus thumb replant for isolated thumb amputation: Critical analysis of functional outcome
Authors: Rosson Gedge D. , Buncke Gregory M. , Buncke Harry J.
Published: October 2008

Background: Thumb replantation following thumb amputation is the standard of care. When replantation is impossible, microneurovascular great toe transplantation is a well‐established option. Methods: A retrospective review was conducted to evaluate functional outcome following isolated thumb replantation or great toe transplantation for thumb reconstruction. From 1974 to 1993, 384 thumb amputations were treated and 110 great toe‐to‐thumb transplantations were performed. Results: Ninety‐one patients with isolated thumb amputation had an 85% survival rate. Failed replants usually resulted from crushing or avulsing injuries. Function of replanted thumbs was better in sharp compared with crush/avulsion injuries. Forty‐three isolated thumb reconstructions had a 93% success rate. Function was comparable with thumb replants from sharp injuries. Interphalangeal motion was significantly better in great toe transplants than in replanted thumbs of the crush/avulsion type. Conclusions: Amputated thumbs should be replanted. When replantation is not possible or unsuccessful, a transplanted great toe functions as well as, or better than, a replanted thumb. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
The timing of microsurgical reconstruction in lower extremity trauma
Authors: Karanas Yvonne L. , Nigriny John , Chang James
Published: October 2008

The timing of post traumatic microsurgical lower extremity reconstruction was defined by Godina in 1986, with recommendations for flap coverage of Gustillo grade IIIb/c fractures within 72 hours of injury. Godina's study showed the highest risk of infection and flap loss in the delayed period (72 hours–90 days). Subsequent authors have also cited lower rates of flap loss and infection when repair was performed “early”. However, the definition of “early” remains ambiguous. We hypothesized that definitive debridement with optimal dressing care, meticulous microsurgical treatment planning, and vessel anastomoses outside of the zone of injury would allow for delayed reconstruction with high success rates. A retrospective review of 14 lower extremity reconstructions with free flaps was undertaken over a 4‐year period. All patients underwent reconstruction in the delayed (>72 hours) period. There were no flap losses and one case of late osteomyelitis. We conclude that lower extremity reconstruction can be performed safely and effectively in the “delayed” period to allow for wound debridement, stabilization of other injuries, and transfer to a microsurgical facility. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.