bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical properties of nanocomposites from sorbitol plasticized starch and tunicin whiskers
Authors: Mathew Aji P. , Thielemans W. , Dufresne Alain 
Published: June 2008

AbstractNanocomposite materials were obtained using sorbitol plasticized waxy maize starch as matrix and tunicin whiskers as the reinforcement. The effect of filler load (0–25 wt % whiskers) and the relative humidity levels (0–98%) on the mechanical behavior of the films are discussed for linear and nonlinear deformation. The performance of the films is explained, based on the morphology and structural behavior of the composite materials (Mathew and Dufresne, Biomacromolecules 2002, 3, 609). The nanocomposites exhibit good mechanical strength due to the strong interaction between tunicin whiskers, matrix, plasticizer (sorbitol), and water, and due to the ability of the cellulose filler to form a rigid three‐dimensional network. The evolution of Tg as a function of relative humidity level and filler load is studied in detail. A decrease in crystallinity of the amylopectin phase is observed at high filler loads, due to the resistance to chain rearrangement imposed by the whiskers. The mechanical strength increased proportionally with filler loads, showing an effective stress transfer from the matrix to the whiskers. An even distribution of whiskers (as determined by SEM) and plasticizer in the matrix contributes to the mechanical performance. The mechanical properties of the nanocomposites showed a strong dependence on relative humidity conditions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Communication and sensing trade‐offs in cooperative mobile networks
Authors: Mostofi Yasamin , Murray Richard M. 
Published: June 2008

AbstractIn this paper we consider the impact of communication noise on distributed sensing and estimation in mobile networks. We characterize when a node should rely on getting information from others and when it should rely on self exploration. In doing so, we explore the trade‐offs between sensing and communication by finding the optimum network configuration under communication constraints. We also show how to achieve the optimum configuration in a distributed manner. While our main results are presented in one dimension (1D), we provide insight into the two dimension (2D) setup and extend a number of key results to 2D. Copyright © 2008 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Paternal environmental exposures and gene expression during spermatogenesis: Research review to research framework
Authors: Hansen Deborah A. 
Published: June 2008

AbstractThe primary objective is to review Dioxin toxicity, the potential impact on spermatogenesis, what is known and unknown about paternal exposures, and the potential mechanisms whereby paternal preconception exposures result in neural tube defects (NTD). The secondary goal is to suggest a versatile research framework utilizing gene expression microarray to evaluate the impact of acute, intermittent, and chronic paternal exposures to environmental agents on gene expression during the stages of spermatogenesis. There are multiple barriers to establishing a paradigm whereby paternal environmental exposures result in adverse birth outcomes. Microarray expression studies are unique in their ability to detect transcription dysregulation, thereby facilitating the identification of molecular and developmental pathways through hierarchical and pathway analysis. To date there are no studies of gene expression during spermatogenesis following exposure to environmental agents. Birth Defects Research (Part C) 84:155–163, 2008. Published 2008 Wiley‐Liss, Inc.
Insights into the establishment of left–right asymmetries in vertebrates
Authors: Raya Ángel , Izpisúa Belmonte Juan Carlos 
Published: June 2008

AbstractThe body‐plan of vertebrates, while exteriorly essentially symmetric along its medio‐lateral plane, displays numerous left‐right differences in the disposition and placement of internal organs. Such left–right asymmetries, established during embryogenesis, are controlled by complex epigenetic and genetic cascades that impart laterality information to the different embryo structures and organ primordia. A key and evolutionarily conserved feature of these information cascades among vertebrate embryos is the left‐sided transfer of information from the node to the lateral plate mesoderm during early somitogenesis stages. We review here recent evidence concerning the mechanisms that regulate the laterality of such transfer. Furthermore, we propose a model of left–right axis specification that underscores the role of the node as an integrator of laterality information and the evolutionary conservation of the mechanisms that convey such information to and from the node. Birth Defects Research (Part C) 84:81–94, 2008. © 2008 Wiley‐Liss, Inc.
Hot‐spot residues at the E9/Im9 interface help binding via different mechanisms
Authors: Wong Sergio E. , Baron Riccardo , McCammon J. Andrew 
Published: June 2008

AbstractProtein–protein association involves many interface interactions, but they do not contribute equally. Ala scanning experiments reveal that only a few mutations significantly lower binding affinity. These key residues, which appear to drive protein–protein association, are called hot‐spot residues. Molecular dynamics simulations of the Colicin E9/Im9 complex show Im9 Glu41 and Im9 Ser50, both hot‐spots, bind via different mechanisms. The results suggest that Im9 Ser50 restricts Glu41 in a conformation auspicious for salt‐bridge formation across the interface. This type of model may be helpful in engineering hot‐spot clusters at protein–protein interfaces and, consequently, the design of specificity. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 916–920, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Späte Eltern. Welchen Risiken sind die Kinder ausgesetzt?
Authors: Rensing Ludger , Mohsenzadeh Saadat 
Published: June 2008

AbstractDie Fertilität von “späten Eltern” nimmt ab – auch der Erfolg einer künstlichen Befruchtung (IVF) – während die Rate der Fehlgeburten steigt. Bei Frauen nimmt vom 35. Lebensjahr an auch das Risiko zu, ein behindertes Kind aufgrund von Chromosomenanomalien, etwa von Trisomie 21 (Down Syndrom) zur Welt zu bringen. Die Zunahme dieser so genannten Aneuploidien liegt vor allem in der langen Ruhephase der Eizellen begründet: Während dieser Ruhephase kann oxidativer Stress Veränderungen in der Bindung der homologen Chromosomen aneinander bzw. an die Kernhülle bewirken und die korrekte Trennung bei der später fortgesetzten Reifeteilung stören. Außer den Aneuploidien können noch weitere Beeinträchtigungen wie Punktmutationen in Oocyten und Spermien auftreten.
2‐D‐Gelelektrophorese zur Trennung komplexer Proteingemische
Authors: Künnemann Eva 
Published: June 2008

AbstractDie 2‐D‐Gelelektrophorese ist eine Technik, um über zehntausend Proteine, die in einer Probe enthalten sind, aufzutrennen. Man kombiniert dabei zwei Trennverfahren: Zum einen werden durch eine isoelektrische Fokussierung die Proteine nach ihrem isoelektrischen Punkt aufgetrennt, zum anderen werden die Proteine senkrecht dazu nach ihrer Größe durch eine SDS‐Polyacrylamidgelelektrophorese separiert.
β‐adrenergic receptors are differentially expressed in distinct interneuron subtypes in the rat hippocampus
Authors: Cox David J. , Racca Claudia , Lebeau Fiona E.N. 
Published: June 2008

AbstractNoradrenaline (NA) acting via β‐adrenergic receptors (βARs) plays an important role in the modulation of memory in the hippocampus. βARs have been shown to be expressed in principal cells, but their distribution across different interneuron classes is unknown. We have used specific interneuron markers including calcium binding proteins (parvalbumin, calbindin, and calretinin) and neuropeptides (somatostatin, neuropeptide Y, and cholecystokinin) together with either β1AR or β2AR to determine the distribution of these receptors in all major subfields of the hippocampus. We found that β1AR‐expressing interneurons were more prevalent in the CA3 and CA1 regions of the hippocampus than in the dentate gyrus, where they were relatively sparse. β2AR‐expressing interneurons were more uniformly distributed between all three regions of the hippocampus. A high proportion of neuropeptide Y‐containing interneurons in the dentate gyrus co‐expressed β2AR. β1AR labeling was common in interneurons expressing somatostatin and parvalbumin in the CA3 and CA1 regions, particularly in the stratum oriens of these regions. β2AR labeling was more likely to be found than β1AR labeling in cholecystokinin‐expressing interneurons. In contrast, calretinin‐containing interneurons were virtually devoid of β1AR or β2AR labeling. These regional and interneuron type‐specific differences suggest functionally distinct roles for NA in modulating hippocampal activity via activation of βARs. J. Comp. Neurol. 509:551–565, 2008. © 2008 Wiley‐Liss, Inc.
Color difference formulas: An unsatisfactory state of affairs
Authors: Kuehni Rolf G. 
Published: June 2008

AbstractColor difference formulas are of considerable importance in production control of colored materials, as they offer a kind of quantitative numerical method to predict perceived differences. Current formulas are based on various sets of empirical difference perception data established with different kinds of materials, under different evaluation conditions, and with different observer panels. The best current formulas predict the average of these perceptual data only with an accuracy of about 65%, a PF/3 value of about 35 (zero being optimal). This article argues that this is an unsatisfactory state of affairs and proposes the development of new uniformly established perceptual data and a new formula/system that predicts the visual results, statistically verified to represent the world‐average observer, with an accuracy of 95%, a PF/3 value (or appropriate improved measure) of 5 or lower. Such a multiyear effort requires a solid experimental plan and a consortium supported by Government and industry to achieve its goal. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 324–329, 2008.
Color‐person‐environment relationships
Authors: Smith Dianne 
Published: June 2008

AbstractAlthough the nature of color and the person environment relationship are both well‐documented, it is posited that both domains need to be integrated to understand the active role that color plays in the relationship between a person and the surrounding environment. The color person environment relationship (COL‐PE) introduced in this article is an important theoretical concept for designers, and as a consequence, for environmental‐color researchers to investigate. The potential of color to be an active agent in the relationship between people and environments is introduced by drawing upon what is known about color and the person environment relationship from other sources. The nature of transition spaces is used to emphasize how color affects the emotional connection and disconnection between people and spaces. As an example of COL‐PE, transition spaces highlight the nature of the person who is also psychologically in‐transition and color as a potentially important aspect of the transitory experience. In addition, the connections between color and the constructs that we hold of the people who visit, work, or live in particular environments will be discussed briefly. Designers often focus on the object or artifact which is being colored (whether a building or a chair) as an end in itself, without considering in any depth how the designed objects or places can influence how people experience their daily activities and each other. COL‐PE is introduced as a means to address this omission and broaden designers' understandings of the potential impact of their work. The discussion of the aspects of environmental design (with particular reference to architecture and interior design), introduces the foundation of the COL‐PE as a particular way of addressing color in the built environment. The principles of COL‐PE are relevant for a range of disciplines involved in environmental design including urban design, landscape architecture, interior design, industrial design, and architecture. The COL‐PE aims to make explicit what is often an unrecognized or tacit understanding of the role of environmental color, and thereby, the article highlights the need for research to understand the relationship more fully. © 2008 Wiley Periodicals, Inc. Col Res Appl, 33, 312–319, 2008.
Age‐related complexity and coupling of children's sitting posture
Authors: Hong S. Lee , James Eric G. , Newell Karl M. 
Published: June 2008

AbstractThis study tested the hypothesis that postural complexity increases as the coupling across the axes of motion decreases as children get older. Children aged 6 and 10 years and young adults (18–23 years) were seated on a wooden box placed atop a force platform that recorded their mediolateral and anteroposterior center of pressure (COP) motion with their feet supported and unsupported. The COP path length and complexity decreased with age, and this was paralleled by an increase in relative phase entropy across the axes of sway motion. The postural sway of the younger children was dominated by slower fluctuations that were more tightly coupled across the axes of motion than the adults. The findings support the postulation that the development of children's sitting posture is characterized by increased freedom in postural coordination that realizes a more loosely coupled but adaptive postural motion with a reduced amount of sway. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 502–510, 2008.
Electron transport properties in the Lucas–Saelee model
Authors: Takeda Akihide , Ikuta Nobuaki 
Published: June 2008

AbstractElectron transport properties for the Lucas–Saelee model in PT and SST conditions are investigated with attention to the effects of ionization. Energy dispersion probabilities through ionization and excitation are compared. A new definition of transverse diffusion coefficient DT′ in steady state with ionization generation of electrons in configuration space is proposed in a form similar to the drift velocity Wr′. Some discussion on the characters of Wr and Wr′ proposed by Tagashira and Ikuta are also given. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(4): 8–14, 2008; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/eej.20495
Principle and basic characteristics of linear synchronous motor with half‐wave rectified self excitation
Authors: Hirayama Tadashi , Oyama Jun , Higuchi Tsuyoshi , Abe Takashi 
Published: June 2008

AbstractThis paper presents the principle and basic characteristics of a novel linear synchronous motor based on “half‐wave rectified self excitation principle.” The field winding is short circuited through a diode and the armature winding consists of conventional three‐phase windings. If the amplitude of the balance three‐phase currents is modulated by an alternating wave with bias frequency, the produced magnetomotive force pulsates at the bias frequency and moves at the synchronous velocity. This pulsating magnetomotive force induces the electromotive force with a bias frequency in the field winding. The field excitation is obtained by rectifying the electromotive force with the diode in the field winding. In this paper, the authors design and build an experimental machine and confirm its basic characteristics. They also deduce the performance equations and investigate the thrust ripple reduction. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(1): 82–90, 2008; Published online in Wiley InterScience (www. interscience.wiley.com). DOI 10.1002/eej.20684
Maximum output power control system of variable‐speed small wind generators
Authors: Amano Yoko , Kajiwara Hiroyuki 
Published: June 2008

AbstractThis paper proposes a maximum output power control system for variable‐speed small wind generators. The proposed control system adjusts the rotational speed of a single‐phase AC generator to the optimum rotational speed, which yields the maximum output power according to the natural wind speed. Since this adjustment is performed on‐line in order to adapt to variations in wind speed, the rotational speed of the single‐phase AC generator is adjusted by controlling the generated current flowing in an FET (field‐effect transistor) device, serving as the generated power brake, which is linked directly to the single‐phase AC generator. In order to reduce heat loss from the FET device, a PWM (pulse width modulation) controller is introduced. An experimental model of the proposed control system was built and tested, and the validity and practicality of the proposed control system were confirmed by the experimental results. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(1): 9–17, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20692
Withholding iron as a cellular defence mechanism – friend or foe?
Authors: Collins Helen L. 
Published: June 2008

AbstractDuring infection one critical host defence strategy is an attempt to withhold iron from invading pathogens. This is achieved by by proinflammatory cytokines such as IL‐6 inducing hepcidin. The net result of this is the removal of iron from the circulation and its sequestration within cells, including cells of the immune system such as macrophages. As macrophages are central cells for controlling infections with intracellular bacteria such as Salmonella and Mycobacteria, modulation of iron by hepcidin can lead to the provision of an ideal cellular iron source for these pathogens. Here we discuss how activation of macrophages with IFN‐γ not only up‐regulates antimicrobial effector mechanisms but also modulates iron regulatory proteins such as ferroportin to reduce intracellular iron availability.See accompanying article: http://dx.doi.org/10.1002/eji.200738056
IL‐21 and autoimmune disease – hypothesis and reality?
Authors: Holmdahl Rikard 
Published: June 2008

AbstractPrevious data have indicated that IL‐21 and/or IL‐21R are crucial for the differentiation of naïve T cells into Th17 cells and also play a key role in the development of autoimmune disease. Given this, IL‐21 and/or IL‐21R are potential targets for therapy of such diseases; however, a study in this issue of the European Journal of Immunology, provides a new twist in the story as it is now shown that IL‐21 and/or IL‐21R play no role in Th17 development or autoimmune inflammatory disease. The reasons for these contradictory data are discussed in this Commentary.See accompanying article: http://dx.doi.org/10.1002/eji.200838511
Neutral and Monocationic Half‐Sandwich Methyl Rare‐Earth Metal Complexes: Synthesis, Structure, and 1,3‐Butadiene Polymerization Catalysis (Eur. J. Inorg. Chem. 18/2008)
Authors: Robert Dominique , Spaniol Thomas P. , Okuda Jun 
Published: June 2008

AbstractThe cover picture shows the reactivity of half‐sandwich bis(aluminate) complexes of the rare‐earth metals that can be converted either into cationic methyl species by protonolysis or into dimeric dimethyl species by donor‐induced cleavage of the aluminate moieties. Details are discussed in the article by J. Okuda et al. on p. 2801 ff.
Polymers from renewable resources: Bulk ATRP of fatty alcohol‐derived methacrylates
Authors: Çayli Gökhan , Meier Michael A. R. 
Published: June 2008

AbstractCopper‐mediated atom transfer radical polymerization (ATRP) of lauryl methacrylate (LMA) and other long‐chain methacrylates was investigated in bulk at 35 °C by using CuCl/N,N,N′,N′,N′′‐pentamethyldiethylenetriamine (PMDETA)/tricaprylylmethylammonium chloride (Aliquat®336) as the catalyst system and ethyl 2‐bromoisobutyrate (EBIB) as the initiator. The investigated monomers can be derived from fatty alcohols and are therefore an important renewable resource for a sustainable development of our future. The amounts of ligand, Aliquat®336 and CuCl were optimized and the effect of their concentrations on the control of the polymerization and the observed conversions were investigated. It was found that a molar ratio of EBIB/CuCl/Ligand/Aliquat®336 of 1 : 1 : 3 : 1 provided the highest conversions of LMA and the best controlled polymerizations. These optimized conditions allowed for the synthesis of poly(lauryl methcarylate)s with different targeted DP (25, 50, 75, 100, 120, 240, and 500), including high‐molecular‐weight polymers with narrow molecular weight distributions. In addition, methacrylate monomers were prepared from fatty alcohols (capric, myristic, palmitic, stearic) and polymerized using the developed procedure to obtain polymers with the same DP and different chain lengths (C10, C12, C14, C16, and C18) of pending alkyl groups. Finally, the thermal properties of these polymers were examined by differential scanning calorimetry and thermogravimetric analysis.
Exploring Nitrone Chemistry: Towards the Enantiodivergent Synthesis of 6‐Substituted 4‐Hydroxypipecolic Acid Derivatives
Authors: Merino Pedro , Mannucci Vanni , Tejero Tomás 
Published: June 2008

AbstractA methodology for the stereoselective preparation of all‐cis 6‐substituted 4‐hydroxypipecolic acid derivatives using nitrone chemistry, involving both nucleophilic additions and cycloadditions, is presented. The N‐benzyl nitrone derived from 1,2‐di‐O‐isopropylidene‐D‐glyceraldehyde was shown to undergo stereocontrolled allylation reactions to provide enantiomerically pure homoallyl hydroxylamines. Further transformation of these substrates into N‐alkenyl nitrones was achieved in high yields and regioselectivities by oxidation with manganese(IV) oxide. The oxidation reaction is thermodynamically controlled and directed by a phenyl group which became the 6‐substituent. A transoximation reaction of the intermediate N‐alkenyl‐C‐phenyl nitrone was needed to add versatility to the methodology by varying the substituent at the 6‐position. The resulting N‐alkenyl nitrones underwent stereoselective intramolecular 1,3‐dipolar cycloaddition reactions to provide the immediate precursors of the target compounds. The selectivity observed in the intramolecular cycloaddition was dictated by both the steric preference and the electronic nature of the substrate, which promoted a hitherto unknown aza‐Cope rearrangement of the N‐alkenyl nitrone. The chiral induction exerted by the dioxolane moiety as well as its synthetic equivalence with the carboxy group provided the basis for the enantiodivergency achieved in the synthesis of 6‐substituted (2R,4S,6R)‐4‐hydroxypipecolic acids and their enantiomers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)