bluuebunny/crossref_metadata_2025 huggingface dataset:
Annotated Bibliography on the Teaching of Psychology: 2002
Authors: Johnson David E. , Schroder Simone I.
Published: January 2004

This bibliography is a continuation of those previously published in Teaching of Psychology (e.g., Berry & Daniel, 1984; Fulkerson & Wise, 1987; Johnson & Schroder, 1997; Wise & Fulkerson, 1996). We maintained similar search methods and criteria for inclusion that were used in previous bibliographies. We also continued the cumulative numbering of the items.

To help the reader locate relevant articles, we arranged items into a small number of subject categories. Generally, if fewer than three items fell into a specific subject category they were relegated to a category labeled miscellaneous.
Laser Flash Photolysis Study of Dialkylphenacylsulfonium Salts
Authors: Kawamura Koichi , Kodama Kunihiko , Hirai Katsuyuki , Tomioka Hideo
Published: January 2004

Laser flash photolysis of the title compound in degassed acetonitrile at room temperature revealed the presence of transient species showing the absorption at 480 nm, regardless of the structure of the precursors. The transient bands are assigned to phenacyl radical presumably formed as a result of the carbon-sulfur bond rather than 1,4-biradicals or cationic species proposed to be formed as a result of Norrish Type II process.
Visualization of Chemical Modification of Pore Internal Surfaces Using Fluorescence Microscopy
Authors: Maekawa Yasunari , Suzuki Yasuyuki , Maeyama Katsuya , Yonezawa Noriyuki , Yoshida Masaru
Published: January 2004

Chemical modification of pore internal surfaces with 0.31 and 0.54 μm in diameter in poly(ethylene terephthalate) (PET) was examined using the alkylation reaction of the carboxylic acids on the surfaces. The chemical incorporation of the reagent on the surfaces was confirmed by the fluorescence microscope images of the membranes reacting with the alkylation reagent bearing a pyrene fluorophore.
Highly Stereoselective Aldol-type Reaction of 2-Bromo-2,3,3,3-tetrafluoropropanamide with Aldehydes Leading to erythro-α-Fluoro-α-(trifluoromethyl)-β-hydroxy Amides
Authors: Sato Kei , Sekiguchi Takashi , Ishihara Takashi , Konno Tsutomu , Yamanaka Hiroki
Published: January 2004

N-Methoxy-N-methyl-2-bromo-2,3,3,3-tetrafluoropropanamide underwent highly stereoselective aldol-type reaction with various aldehydes under the influence of triphenylphosphine—a catalytic amount of titanium(IV) isopropoxide at room temperature to give the erythro-isomers of α-fluoro-α-(trifluoromethyl)-β-hydroxy amides preferentially in good to excellent yields.
Amphoteric Quinone–azine–cyclopentadithiophene System
Authors: Kozaki Masatoshi , Igarashi Hiroaki , Okada Keiji
Published: January 2004

Various quinoid groups have been connected with the cyclopentadithiophene (CPDT) skeleton via azine linkage to form a new D–π–A system. These compounds revealed weak absorptions extending to 590–630 nm, corresponding to small HOMO–LUMO gaps of 1.97–2.10 eV. Their reduction potentials were strongly dependent on the quinone moieties, whereas the oxidation potentials were controlled by the CPDT moiety. Some of these compounds underwent oxidative polymerization under electrochemical conditions to yield polymers with a highly amphoteric character.
Fabrication and Characterization of Novel Mixed-valence Pentaamminechlororuthenium(III) Hexacyanoruthenate(II) Coordination Compound Self-assembled Film
Authors: Wei Tianxin , Tamada Kaoru , Yokokawa Shinobu , Ito Eisuke , Yase Kiyoshi , Hara Masahiko
Published: January 2004

Functional self-assembled film of a class II mixed-valence coordination compound, pentaamminechlororuthenium(III) hexacyanoruthenate(II) (Na[NH3]5Ru(III)-CN-Ru(II)(CN)5), was fabricated and characterized by surface plasmon resonance (SPR), X-ray photoelectron spectroscopy (XPS) and phase modulation infrared reflection–absorption spectroscopy (PMIRRAS).
Polyhedral Methods for Adaptive Choice-Based Conjoint Analysis
Authors: Toubia Olivier , Hauser John R. , Simester Duncan I.
Published: January 2004

The authors propose and test a new “polyhedral” choice-based conjoint analysis question-design method that adapts each respondent's choice sets on the basis of previous answers by that respondent. Polyhedral “interior-point” algorithms design questions that quickly reduce the sets of partworths that are consistent with the respondent's choices. To identify domains in which individual adaptation is promising (and domains in which it is not), the authors evaluate the performance of polyhedral choice-based conjoint analysis methods with Monte Carlo experiments. They vary magnitude (response accuracy), respondent heterogeneity estimation method, and question-design method in a 4 × 23 experiment. The estimation methods are hierarchical Bayes and analytic center. The latter is a new individual-level estimation procedure that is a by-product of polyhedral question design. The benchmarks for individual adaptation are random designs, orthogonal designs, and aggregate customization. The simulations suggest that polyhedral question design does well in many domains, particularly those in which heterogeneity and partworth magnitudes are relatively large. The authors test feasibility, test an important design criterion (choice balance), and obtain empirical data on convergence by describing an application to the design of executive education programs in which 354 Web-based respondents answered stated-choice tasks with four service profiles each.
Integration of Discrepant Sales Forecasts: The Influence of Plausibility Inferences Based on an Evoked Range
Authors: Roggeveen Anne L. , Johar Gita Venkataramani
Published: January 2004

The authors hypothesize that when managers integrate two projections to form a sales estimate, they evoke and use a sales range to judge inappropriately the plausibility of each projection. This judged plausibility, as well as the “margin of error” (based on the market research company's typical accuracy), is used to assign weights to each projection. Five experiments find strong evidence for this process and demonstrate a resulting bias.
Recapturing Lost Customers
Authors: Thomas Jacquelyn S. , Blattberg Robert C. , Fox Edward J.
Published: January 2004

For both academics and practitioners, the dominant focus of customer relationship management has been customer retention. The authors assert that customer winback should also be an important part of a customer relationship management strategy. Customer winback focuses on the reinitiation and management of relationships with customers who have lapsed or defected from a firm. In some cases, firms engage in extensive efforts to reacquire lapsed customers or defectors, and a common tactic is lowering the price to reacquire a customer. This investigation goes beyond the reacquisition pricing strategy and also examines the optimal pricing strategy when the customer has decided to reinitiate the relationship. By simultaneously modeling reacquisition and duration of the second tenure with the firm, the authors determine that the optimal pricing strategy for their application involves a low reacquisition price and higher prices when customers have been reacquired. In addition to pricing strategy, they also discuss the implications of their findings for targeting lapsed customers for reacquisition.
Valenced Comparisons
Authors: Jain Shailendra Pratap , Posavac Steven S.
Published: January 2004

In this article, the authors show empirically that comparative advertisements can vary in terms of their valence, that is, whether respondents perceive them as positive (less derogatory) or negative (more derogatory) in their references to competition. In addition, the authors report findings from three studies that demonstrate that advertisements perceived as carrying more negative/derogatory references to competition result in more counterarguments, fewer support arguments, lower believability more associated perceived bias, and lower brand attitude scores than do advertisements perceived as more positive/nonderogatory in their competitive references. Tests of mediation suggest that the effectiveness of valenced comparisons is mediated by advertiser attributions that are more negative for negative comparisons. The authors discuss implications for designing more effective comparative advertisements.
Immunoblockage of 9-O-Acetyl GD3 Ganglioside Arrests theIn VivoMigration of Cerebellar Granule Neurons
Authors: Santiago Marcelo F. , Costa Marcos R. , Mendez-Otero Rosalia
Published: January 2004

During development of the cerebellum, radial glial cells guide the migration of granule cell precursors from the external granular cell layer toward the internal granular cell layer. The cellular membranes of migrating neurons and glial fibers organize a specialized migration junction at the site of contact between these cells, and several molecules have been implicated in the control of this glial-guided neuronal migration program. The monoclonal antibody Jones (mAb Jones) recognizes the ganglioside 9-O-acetyl GD3, which is expressed in migratory profiles in the developing and adult CNS. Recently, this ganglioside was suggested to play a role in neuronal migration in cerebellar cultures. In this report, we use antibody perturbation assays to investigate a possible role of 9-O-acetyl GD3 in the neuronal migration programin vivo. The results show that chronic intracerebroventricular administration of mAb Jones arrests neuronal migration in the developing cerebellum of live animals. Proliferating granule cell precursors were labeled with 5-bromo-2′-deoxyuridine (BrdU), and their migratory behavior was analyzed and compared with control groups. Immunoblockage of 9-O-acetyl GD3 arrests 43% of the BrdU-labeled granule precursors in the external granular cell layer. Together with our previous results, this report strongly suggests that the ganglioside 9-O-acetyl GD3 plays a crucial role in the migration of cerebellar granule cells along radial glial fibers in the developing rat cerebellum.
Monocular Enucleation Induces Nuclear Localization of Calcium/Calmodulin-Dependent Protein Kinase IV in Cortical Interneurons of Adult Monkey Area V1
Authors: Lalonde Jasmin , Lachance Pascal E. D. , Chaudhuri Avi
Published: January 2004

Elevation of intracellular Ca2+levels activates calcium/calmodulin-dependent protein kinase (CaMK) IV, which in turn plays an important role in neuroprotection and neuroplasticity. The possibility that CaMKIV is similarly involved in neocortical tissue has not been examined previously, especially with regard to the plastic nature of ocular dominance features in the primary visual cortex (area V1). We addressed this question by way of monocular enucleation (ME) to disrupt sensory input and examine CaMKIV expression changes in monkey area V1. Immunohistochemical staining of area V1 in normal infants showed a nuclear presence of CaMKIV, which did not changed after ME. However, a striking set of layer- and time-dependent changes in nuclear CaMKIV expression was observed in adult area V1 after ME. A strong increase in nuclear CaMKIV levels was evident in cortical layers II/III and VI after 1 d of ME and in layer IVC after 5 d of ME. These specific laminar changes persisted after 30 d of ME and, most notably, showed a columnar profile in which CaMKIV expression was linked to open-eye columns. Real-time quantitative reverse transcription-PCR and Western blot analysis showed that total amounts of CaMKIV mRNA and protein remained unchanged after ME, suggesting that a nuclear translocation may occur from the cytoplasm. Finally, double-label immunohistochemical staining with a pyramidal cell marker (SMI-32) showed that CaMKIV was absent in this subtype, whereas coincidental expression with GABA, parvalbumin, and calretinin, but not calbindin, showed its clear presence in a subset of interneurons. We propose that CaMKIV activity within diverse groups of cortical interneurons may play an important role in adaptive plastic reorganization of adult neocortical tissue.
Keratan Sulfate Proteoglycan Phosphacan Regulates Mossy Fiber Outgrowth and Regeneration
Authors: Butler Christy D. , Schnetz Stephanie A. , Yu Eric Y. , Davis Joseph B. , Temple Katherine , Silver Jerry , Malouf Alfred T.
Published: January 2004

We have examined the role of chondroitin sulfate proteoglycans (CSPGs) and keratan sulfate proteoglycans (KSPGs) in directing mossy fiber (MF) outgrowth and regeneration in rat hippocampal slice cultures. MFs normally exhibit a very specific innervation pattern that is restricted to the stratum lucidum (SL). In addition, MFs in hippocampal slice cultures will regenerate this specific innervation pattern after transection. CSPGs are one of the best characterized inhibitory axon guidance molecules in the CNS and are widely expressed in all areas of the hippocampus except SL. KSPGs are also widely expressed in the hippocampus, but their role in axon outgrowth has not been extensively studied in the CNS where phosphacan is the only protein that appears to contain KS-GAGs. Cultured hippocampal slices were treated with either chondroitin ABC lyase or keratanases to reduce the inhibitory axon guidance properties of CS and KS proteoglycans, respectively. The ability of transected MFs to regenerate their normal innervation pattern after digestion of CS and KS-GAGS sugars with these enzymes was examined. Only keratanase treatment resulted in misrouting of MFs. Identifying the mechanism by which keratanase produced MF misrouting is complicated by the presence of splice variants of the phosphacan gene that include the extracellular form of phosphacan and the transmembrane receptor protein tyrosine phosphatase β/ζ (RPTPβ/ζ). Both forms of phosphacan are made by astrocytes, suggesting that keratanase alters MF outgrowth by modifying astrocyte function.
Locking the Dimeric GABABG-Protein-Coupled Receptor in Its Active State
Authors: Kniazeff Julie , Saintot Pierre-Philippe , Goudet Cyril , Liu Jianfeng , Charnet Annie , Guillon Gilles , Pin Jean-Philippe
Published: January 2004

G-protein-coupled receptors (GPCRs) play a major role in cell-cell communication in the CNS. These proteins oscillate between various inactive and active conformations, the latter being stabilized by agonists. Although mutations can lead to constitutive activity, most of these destabilize inactive conformations, and none lock the receptor in an active state. Moreover, GPCRs are known to form dimers, but the role of each protomer in the activation process remains unclear. Here, we show that the heterodimeric GPCR for the main inhibitory neurotransmitter, the GABABreceptor, can be locked in its active state by introducing two cysteines expected to form a disulphide bridge to maintain the binding domain of the GABAB1subunit in a closed form. This constitutively active receptor cannot be inhibited by antagonists, but its normal functioning, activation by agonists, and inhibition by antagonists can be restored after reduction with dithiothreitol. These data show that the closed state of the binding domain of GABAB1is sufficient to turn ON this heterodimeric receptor and illustrate for the first time that a GPCR can be locked in an active conformation.
The Central Fragment of Reelin, Generated by Proteolytic ProcessingIn Vivo, Is Critical to Its Function during Cortical Plate Development
Authors: Jossin Yves , Ignatova Nina , Hiesberger Thomas , Herz Joachim , Lambert de Rouvroit Catherine , Goffinet André M.
Published: January 2004

Reelin is a large extracellular protein that controls cortical development. It binds to lipoprotein receptors very-low-density lipoprotein receptor and apolipoprotein-E receptor type 2, thereby inducing phosphorylation of the adapter Dab1.In vivo, Reelin is cleaved into three fragments, but their respective function is unknown. Here we show the following: (1) the central fragment is necessary and sufficient for receptor bindingin vitroand for Dab1 phosphorylation in neuronal cultures; (2) Reelin does not bind the protocadherin cadherin-related neuronal receptor (CNR1) as reported previously; (3) Reelin and its central fragment are equally able to rescue thereelerphenotype in a slice culture assay; and (4) anti-receptor antibodies can induce Dab1 phosphorylation but do not correct thereelerphenotype in slices. These observations show that the function of Reelin is critically dependent on the central fragment generated by processing but primarily independent of interactions with CNR1 and on the N-terminal region. They also indicate that events acting in parallel to Dab1 phosphorylation might be required for full activity.
Brain-Derived Neurotrophic Factor Modulates Fast Synaptic Inhibition by Regulating GABAAReceptor Phosphorylation, Activity, and Cell-Surface Stability
Authors: Jovanovic Jasmina N. , Thomas Philip , Kittler Josef T. , Smart Trevor G. , Moss Stephen J.
Published: January 2004

The efficacy of GABAergic synaptic inhibition is a principal factor in controlling neuronal activity. We demonstrate here that brain-derived neurotrophic factor modulates the activity of GABAAreceptors, the main sites of fast synaptic inhibition in the brain, within minutes of application. Temporally, this comprised an early enhancement in the miniature IPSC amplitude, followed by a prolonged depression. This modulation was concurrent with enhanced PKC-mediated phosphorylation, followed by protein phosphatase 2A (PP2A)-mediated dephosphorylation of the GABAAreceptor. Mechanistically, these events were facilitated by differential recruitment of PKC, receptor for activated C-kinase, and PP2A to GABAAreceptors, depending on the phosphorylation state of the receptor β3-subunit. Thus, transient formation of GABAAreceptor signaling complexes has the potential to provide a basis for acute changes in receptor function underlying GABAergic synaptic plasticity.
PSD93 Regulates Synaptic Stability at Neuronal Cholinergic Synapses
Authors: Parker Michael J. , Zhao Shengli , Bredt David S. , Sanes Joshua R. , Feng Guoping
Published: January 2004

Neuronal cholinergic synapses play important roles in both the PNS and CNS. However, the mechanisms that regulate the formation, maturation, and stability of neuronal cholinergic synapses are poorly understood. In this study, we use the readily accessible mouse superior cervical ganglion (SCG) and submandibular ganglion (SMG) to examine the assembly of the postsynaptic complex of neuronal cholinergic synapses. We find that novel splicing forms of PSD93 (postsynaptic density 93) are expressed in SCG. By immunostaining, we show that PSD93 proteins precisely colocalize with neuronal nicotinic acetylcholine receptors (nAChRs) at synapses of the SCG and SMG. Subcellular fractionation demonstrates that PSD93 is enriched in the PSD fraction of SCG, and coimmunoprecipitation shows that PSD93 and neuronal nAChRs form a complexin vivo. Furthermore, two additional components of the well characterized glutamatergic postsynaptic complex, GKAP/SAPAP (guanylate kinase domain-associated protein/synapse-associated protein-associated protein) and Shank/ProSAP family proteins, are also present at neuronal cholinergic synapses. To assess the function of this protein complex at neuronal cholinergic synapsesin vivo, we examined ganglia in mice that lack PSD93. We find that neuronal cholinergic synapses form properly in PSD93 null mice. After denervation, however, synaptic clusters of nAChRs disassemble much faster in mice lacking PSD93 than those in wild-type mice. These results demonstrate that PSD93 is a key component of the postsynaptic scaffold at neuronal cholinergic synapses and plays an important role in synaptic stability. In addition, these results suggest that the mechanism of postsynaptic scaffolding is conserved between neuronal cholinergic and glutamatergic synapses.
5-Aminoimidazole-4-Carboxamide-1-β-4-Ribofuranoside Inhibits Proinflammatory Response in Glial Cells: A Possible Role of AMP-Activated Protein Kinase
Authors: Giri Shailendra , Nath Narendra , Smith Brian , Viollet Benoit , Singh Avtar K. , Singh Inderjit
Published: January 2004

AMP-activated protein kinase (AMPK) is tightly regulated by the cellular AMP:ATP ratio and plays a central role in the regulation of energy homeostasis and metabolic stress. A pharmacological activator of AMPK, 5-amino-4-imidazole carboxamide riboside (AICAR) inhibited lipopolysaccharide (LPS)-induced expression of proinflammatory cytokines (tumor necrosis factor α, interleukin-1β, and interleukin-6) and inducible nitric oxide synthase in primary rat astrocytes, microglia, and peritoneal macrophages. AICAR attenuates the LPS-induced activation of nuclear factor κB via downregulation of IκB kinase α/β activity. It also inhibits nuclear translocation of CCAAT/enhancer-binding protein (C/EBP) transcription factor by inhibiting the expression of C/EBP-δ in brain glial cells. The dominant negative form of AMPKα2(D157A) and its antisense documents a possible role of AMPK in the regulation of the cellular proinflammatory process. AICAR also inhibited the production of inflammatory mediators in serum and their expression in CNS of rats injected with a sublethal dose of LPS by intraperitoneal injection. These observations in cultured cells as well as in the animal model suggest that AICAR may be of therapeutic value in treating inflammatory diseases.
Dysregulated IP3Signaling in Cortical Neurons of Knock-In Mice Expressing an Alzheimer's-Linked Mutation inPresenilin1Results in Exaggerated Ca2+Signals and Altered Membrane Excitability
Authors: Stutzmann Grace E. , Caccamo Antonella , LaFerla Frank M. , Parker Ian
Published: January 2004

Disruptions in intracellular Ca2+signaling are proposed to underlie the pathophysiology of Alzheimer's disease (AD), and it has recently been shown that AD-linked mutations in thepresenilin 1gene (PS1) enhance inositol triphosphate (IP3)-mediated Ca2+liberation in nonexcitable cells. However, little is known of these actions in neurons, which are the principal locus of AD pathology. We therefore sought to determine howPS1mutations affect Ca2+signals and their subsequent downstream effector functions in cortical neurons. Using whole-cell patch-clamp recording, flash photolysis, and two-photon imaging in brain slices from 4-5-week-old mice, we show that IP3-evoked Ca2+responses are more than threefold greater inPS1M146Vknock-in mice relative to age-matched nontransgenic controls. Electrical excitability is thereby reduced via enhanced Ca2+activation of K+conductances. Action potential-evoked Ca2+signals were unchanged, indicating thatPS1M146Vmutations specifically disrupt intracellular Ca2+liberation rather than reduce cytosolic Ca2+buffering or clearance. Moreover, IP3receptor levels are not different in cortical homogenates, further suggesting that the exaggerated cytosolic Ca2+signals may result from increased store filling and not from increased flux through additional IP3-gated channels. Even in young animals,PS1mutations have profound effects on neuronal Ca2+and electrical signaling: cumulatively, these disruptions may contribute to the long-term pathophysiology of AD.
Template‐Assisted Self‐Assembly of Spherical Colloids into Complex and Controllable Structures
Authors: Xia Y. , Yin Y. , Lu Y. , McLellan J.
Published: January 2004

Colloidal aggregates with well‐controlled sizes, shapes, and structures have been fabricated by dewetting aqueous dispersions of monodispersed spherical colloids across surfaces patterned with two‐dimensional arrays of relief structures (or templates). The capability and feasibility of this approach have been demonstrated with the organization of polymer latex or silica beads into homo‐aggregates, including circular rings; polygonal and polyhedral clusters; and linear, zigzag, and spiral chains. It was also possible to generate hetero‐aggregates in the configuration of HF and H2O molecules that contained spherical colloids of different sizes, compositions, densities, functions, or a combination of these features. These uniform, well‐defined aggregates of spherical colloids are ideal model systems to investigate the aerodynamic, hydrodynamic, and optical properties of colloidal particles characterized by non‐spherical shapes and/or complex topologies. They can also serve as a new class of building blocks to generate hierarchically self‐assembled structures that are expected to exhibit interesting features valuable to areas ranging from condensed matter physics to photonics.
Oriented Growth of Self‐Assembled Polyaniline Nanowire Arrays Using a Novel Method
Authors: Qiu H. , Zhai J. , Li S. , Jiang L. , Wan M.
Published: January 2004

A novel method for fabrication of highly oriented polyaniline (PANI) nanowires without removal of the template was developed by combining self‐assembly and template synthesis techniques. By using a self‐assembly process under inhibition conditions, oriented arrays of PANI nanowires growing out of the nanoporous template were obtained, with nanowire diameters ranging from 110 to 190 nm and lengths of several micrometers. The lengths of these wires can be roughly controlled by the polymerization time.
2,7‐Bis(diarylamino)‐9,9‐dimethylfluorenes as Hole‐Transport Materials for Organic Light‐Emitting Diodes
Authors: Hreha R.D. , George C.P. , Haldi A. , Domercq B. , Malagoli M. , Barlow S. , Brédas J.‐L. , Kippelen B. , Marder S.R.
Published: January 2004

2,7‐Bis(p‐methoxyphenyl‐m′‐tolylamino)‐9,9‐dimethylfluorene (1′), 2,7‐bis(phenyl‐m′‐tolylamino)‐9,9‐dimethylfluorene (2′) and 2,7‐bis(p‐fluorophenyl‐m′‐tolylamino)‐9,9‐dimethylfluorene (3′) have been synthesized using the palladium‐catalyzed reaction of the appropriate diarylamines with 2,7‐dibromo‐9,9‐dimethylfluorene. These molecules have glass‐transition temperatures 15–20 °C higher than those for their biphenyl‐bridged analogues, and are 0.11–0.14 V more readily oxidized. Fluorescence spectra and fluorescence quantum yields for dimethylfluorene‐bridged and biphenyl‐bridged species are similar, but the peaks of the absorption spectra of 1′–3′ are considerably red‐shifted relative to those of their biphenyl‐bridged analogues. Time‐of‐flight hole mobilities of 1′–3′/polystyrene blends are in a similar range to those of the biphenyl‐bridged analogues. Analysis according to the disorder formalism yields parameters rather similar to those for the biphenyl species, but with somewhat lower zero‐field mobility values. Density functional theory (DFT) calculations suggest that the enforced planarization of the fluorene bridge leads to a slightly larger reorganization energy for the neutral/cation electron‐exchange reaction than in the biphenyl‐bridged system. Organic light‐emitting diodes have been fabricated using 1′–3′/polystyrene blends as the hole‐transport layer and tris(8‐hydroxy quinoline)aluminium as the electron‐transport layer and lumophore. Device performance shows a correlation with the ionization potential of the amine materials paralleling that seen in biphenyl‐based systems, and fluorene species show similar performance to biphenyl species with comparable ionization potential.
Fabrication of Conducting Polymer and Complementary Gold Microstructures Using Polymer Brushes as Templates
Authors: Zhou F. , Liu W. , Hao J. , Xu T. , Chen M. , Xue Q.
Published: January 2004

This article describes a strategy to fabricate a conducting polymer and complementary gold microstructures through selective electrodeposition and wet chemical etching on a chemically tethered polymer brush template that is prepared by surface‐initiated atomic transfer radical polymerization (ATRP) and subsequent photopatterning. The polymer brush acts as a sufficient insulating barrier and thus the polypyrrole (PPy) can be grown from the exposed area of the polymer brush template. Different polymer brushes provide different protection actions in selective etching, which is utilized to generate complementary (negative or positive) gold pattern on a single template in different manners.
Hydrothermal Synthesis of Rare Earth (Tb, Y) Hydroxide and Oxide Nanotubes
Authors: Fang Y.‐P. , Xu A.‐W. , You L.‐P. , Song R.‐Q. , Yu J.C. , Zhang H.‐X. , Li Q. , Liu H.‐Q.
Published: January 2004

In this paper, Tb(OH)3 and Y(OH)3 single‐crystalline nanotubes with outer diameters of 30–260 nm, inner diameters of 15–120 nm, and lengths of up to several micrometers were synthesized on a large scale by hydrothermal treatment of the corresponding oxides in the presence of alkali. In addition, Tb4O7 and Y2O3 nanotubes can be obtained by calcination of Tb(OH)3 and Y(OH)3 nanotubes at 450 °C. X‐ray diffraction (XRD), field‐emission scanning electron microscopy, transmission electron microscopy (TEM), electron diffraction (ED), energy‐dispersive X‐ray spectroscopy (EDS), thermogravimetry, and differential scanning calorimetry (DSC) have been employed to characterize these nanotube materials. The growth mechanism of rare earth hydroxide nanotubes can be explained well by the highly anisotropic crystal structure of rare earth hydroxides. These new types of rare earth compound nanotubes with open ends have uses in a variety of promising applications such as luminescent devices, magnets, catalysts, and other functional materials. Advantages of this method for easily realizing large‐scale production include that it is a simple and unique one‐pot synthetic process without the need for a catalysts or template, is low cost, has high yield, and the raw materials are readily available. The present study has enlarged the family of nanotubes available, and offers a possible new, general route to one‐dimensional single‐crystalline nanotubes of other materials.
Anisotropic Change of Liquid‐Crystal Domains by Polarized Infrared Pulse Laser Irradiation for a Columnar Mesophase
Authors: Monobe H. , Kiyohara K. , Terasawa N. , Heya M. , Awazu K. , Shimizu Y.
Published: January 2004

The infrared photoinduced alignment change of liquid‐crystal domains was investigated for a hexagonal columnar mesophase of a liquid‐crystalline triphenylene derivative. A uniform and anisotropic alignment change of domains was observed when a polarized infrared (IR) light corresponding to the wavelength of the aromatic C–C stretching absorption band of the triphenylene core was used to irradiate the sample. The relationship between the aligned azimuthal angle of the columnar axis and the polarization of the IR incident irradiation was investigated. IR absorption dichroism is induced as a result of the reorientation of triphenylene core. Texture observation and polarizing microscope FTIR spectra show that a change of the molecular alignment occurred and that the direction of columns depends on the polarization angle of the IR light used for irradiation. The mechanism of the alignment change in a columnar liquid crystal film by IR irradiation is also discussed. The technique could provide a novel technology to control the columnar alignment of highly viscous liquid crystals.
Fabrication of Magnetic Carbon Nanotubes Using a Metal‐Impregnated Polymer Precursor
Authors: Jang J. , Yoon H.
Published: January 2004

γ‐Fe2O3‐impregnated magnetic carbon nanotubes (CNTs) have been fabricated by the carbonization of polypyrrole (PPy) nanotubes. It is found that PPy nanotubes form graphitic structures at a low temperature (800 °C). Magnetic CNTs (see Figure) show ferromagnetic behavior even at 300 K and the main magnetic phase of the CNTs is γ‐Fe2O3. This novel fabrication approach is expected to provide an alternative way to fabricate CNTs.
New Branched Thiophene‐Based Oligomers for Bright Organic Light‐Emitting Devices
Authors: Mazzeo M. , Vitale V. , Della Sala F. , Pisignano D. , Anni M. , Barbarella G. , Favaretto L. , Zanelli A. , Cingolani R. , Gigli G.
Published: January 2004

A new class of oligothiophenes is realized by replacing the conventional linear structure with a branched benzo[b]thiophene‐based structure (see Figure). These compounds are used as active materials in light‐emitting diodes exhibiting record luminances up to 10 500 cd m–2 (see inset). Optical measurements and theoretical calculations show these performances are mainly to the distorted molecular structure.
High‐Strength Apatitic Cement by Modification with α‐Hydroxy Acid Salts
Authors: Barralet J.E. , Hofmann M. , Grover L.M. , Gbureck U.
Published: January 2004

High‐strength hydroxyapatite orthopaedic cements have been prepared by the addition of sodium citrate to the liquid phase, which liquified the mixture enabling high‐density, low‐temperature ceramics to be fabricated (see Figure, a fracture surface). Wet compressive strengths well within the range for cortical bone were measured. Following compaction at low pressures the cements were still moldable.
Anomalous Expansion of CeO2 Nanocrystalline Membranes
Authors: Nair J.P. , Wachtel E. , Lubomirsky I. , Fleig J. , Maier J.
Published: January 2004

Nanocrystalline, nominally undoped films of CeO2–x undergo large (0.8–2 %) lateral expansion after local substrate removal and formation of freestanding membranes (see Figure). The structural, optical, and electrical properties are consistent with the hypothesis that substrate removal triggers disordering of oxygen vacancies leading to this expansion, which occurs irrespective of whether tensile or compressive stress existed in the films.
Static and Dynamic Properties of Optical Microcavities in Photonic Bandgap Yarns
Authors: Benoit G. , Hart S.D. , Temelkuran B. , Joannopoulos J.D. , Fink Y.
Published: January 2004

The design, fabrication, and characterization of polymeric yarns (see Figure and cover) with large photonic bandgaps and omnidirectional reflectivity combined with a micro‐cavity designed for near‐infrared applications are reported. The reversible shift of the resonant wavelength of this single‐mode optical cavity under applied strain is also demonstrated. Passive and active applications include narrow band‐pass filters and low‐threshold lasers.
Solution‐Processed Organic n‐Type Thin‐Film Transistors
Authors: Waldauf C. , Schilinsky P. , Perisutti M. , Hauch J. , Brabec C.J.
Published: January 2004

An organic n‐type transistor, where both insulating and active layer were processed from solution, has been produced. As the active layer the C60‐derivative, [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM), was used. Its electron mobility was determined to be as high as μe = 4.5 × 10–3 cm2 V–1 s–1 when calcium drain/source contacts were used. If these contacts are formed from more air‐stable metals, the device performance decreases.
Up‐Conversion Photoluminescence in Polyfluorene Doped with Metal(II)–Octaethyl Porphyrins
Authors: Keivanidis P.E. , Baluschev S. , Miteva T. , Nelles G. , Scherf U. , Yasuda A. , Wegner G.
Published: January 2004

The up‐conversion photoluminescence (PL) in films of polyfluorene (PF) doped with metallated porphyrins is reported for the first time. The dependence of the up‐conversion process on the pump laser intensity and wavelength, the central metal moiety of the dopants, and the temperature is presented. Up‐conversion emission is observed at pump intensities as low as 2 kW cm–2. Comparison of the PF integral PL intensities after laser excitation by 532, 543, and 405 nm enables the discussion of the energy‐transfer mechanism and the efficiency of the process.
Vapor–Liquid–Solid Growth of Silicon–Germanium Nanowires
Authors: Lew K.‐K. , Pan L. , Dickey E.C. , Redwing J.M.
Published: January 2004

SiGe alloy nanowires (see Figure) have been fabricated using vapor–liquid–solid (VLS) growth with silane (SiH4) and germane (GeH4) gas sources. Growth conditions have been identified that produce nanowires with homogeneous alloy composition with negligible Ge coating on the wire surface. The Ge composition in the nanowire can be controlled by varying the inlet GeH4/(GeH4 + SiH4) gas ratio.
Synthesis and Characterization of Magnetic Iron Sulfide Nanowires
Authors: Nath M. , Choudhury A. , Kundu A. , Rao C.N.R.
Published: January 2004

Large quantities of Fe1–xS (x = 0.12 and 0.1–0.08) nanowires (see Figure) have been prepared by the thermal decomposition of a hybrid precursor, Fe1–xS(en)0.5 (x = 0.2–0.3, en = ethylenediamine). Removal of the amine from Fe1–xS(en)0.5 at 200 and 300 °C under Ar flow yields Fe7S8 and Fe1–xS (x ≈ 0.09) nanowires, respectively, with well‐defined morphologies. The Fe7S8 nanowires are ferrimagnetic at room temperature.
Lithium Storage in Ordered Mesoporous Carbon (CMK‐3) with High Reversible Specific Energy Capacity and Good Cycling Performance
Authors: Zhou H. , Zhu S. , Hibino M. , Honma I. , Ichihara M.
Published: January 2004

Carbonaceous materials with high specific energy capacity are prime candidates for applications in rechargeable lithium batteries. The authors report the synthesis and characterization of ordered mesoporous carbon (CMK‐3), synthesized using ordered silica as a template, with high reversible specific capacity and good charge–discharge cycle characteristics. The performance of CMK‐3 is compared with that of carbon nanotubes, and its superiority is suggested to be related to the three‐dimensional ordered structure of CMK‐3.
Nonmetric cranial trait variation and prehistoric biocultural change in the Azapa Valley, Chile
Authors: Sutter Richard C. , Mertz Lisa
Published: January 2004

Historically, interpretations of both biological and cultural change within the prehistoric Azapa Valley, northern Chile, have cited large‐scale population movements, with replacement from complex societies located in the adjacent highlands to the east. Biological estimates of this change have traditionally relied upon biodistance estimates, using craniofacial measures of both deformed and nondeformed skulls. In order to evaluate whether large‐scale prehistoric migrations occurred in the Azapa Valley, we examine biodistance results from nonmetric cranial traits for eight mortuary samples that represent all time periods of prehistoric occupation of the valley. None of the mean measures of divergences (MMD) among mortuary samples examined by this study were significant. These results suggest biological continuity in the Azapa Valley during 5,000 years of prehistory, with nonsignificant gene flow during the late Middle Horizon (AD 750–1100) and Late Intermediate (AD 1100–1476) periods. Biodistance results also suggest endogamy within coastal and inland populations. The broader implications of these results are discussed. Am J Phys Anthropol, 2003. © 2003 Wiley‐Liss, Inc.
Identifying optimum locations for new ponds
Authors: Davies Bella R. , Biggs Jeremy , Lee John T. , Thompson Stewart
Published: January 2004

Pond ecological quality is influenced by surrounding land uses. Continued intensification of land use has led to a progressive decline in the ecological quality of the pond stock within Britain.

To reverse this trend new ponds need to be carefully designed and sited using a targeted approach. Consequently, this study uses a Geographical Information System (GIS) to identify optimum locations for new ponds within the Chiltern Hills Area of Outstanding Natural Beauty.

Multiple regression analysis was used to identify the relationship between macrophyte pond quality indicators and environmental data from 300 ponds to produce models that could predict pond quality.

These models were tested at 10 locations in the study area by comparing predicted pond qualities with the actual pond qualities, established by identifying all plants in each pond. Aquatic plants successfully predicted pond quality, while emergent plants and total wetland plant species did not.

The regression model for aquatic plants was used in the GIS to identify locations within the study area where new ponds could be located to obtain maximum ecological quality. Six scenarios were tested and the optimum situation identified.

The study demonstrated the potential and importance of using GIS in a strategic approach for pond conservation.

Copyright © 2003 John Wiley & Sons, Ltd.
Assessing redesigned effectiveness of the water quality monitoring program in the Indian River Lagoon, Florida
Authors: Sigua Gilbert C. , Tweedale Wendy A.
Published: January 2004

In 1996, the long‐term water quality monitoring network (WQMN) program in the Indian River Lagoon (IRL) of the St. Johns River Water Management District (SJRWMD) that began in 1988 was redesigned to eliminate statistically redundant sampling and satisfy modeling requirements.

Methods, procedures, and equipment were standardized across multi‐agency monitoring partners to produce reliable and comparable data. The redesigned strategy also included elements to determine previously unknown quantities such as differences in water quality parameters with depth and tidal cycle.

Reduction of sampling sites from 150 to 24 resulted in a significant improvement of standard deviation (t‐test; α = 0.05) for most water quality parameters analysed. The enhancement in data quality has demonstrated a more cost‐effective and efficient monitoring tool to measure the water quality of the seagrass environment in the IRL.

Results supported the view of a well‐mixed condition at the sampling stations on most days. Refocusing and streamlining the water quality monitoring program within the context of its mission would enable conversion of data into meaningful information regarding the interrelationship among water quality, photosynthetically active radiation (PAR), and seagrass PAR requirements.

Copyright © 2003 John Wiley & Sons, Ltd.
Are River Styles ecologically meaningful? A test of the ecological significance of a geomorphic river characterization scheme
Authors: Thomson James R. , Taylor Mark P. , Brierley Gary J.
Published: January 2004

Classification is a useful tool for researchers and managers wishing to group functionally similar sites or to identify unique or threatened habitats. A process‐based river classification scheme that successfully integrates physical and biological aspects of lotic form and function would enhance conservation and restoration efforts by allowing more meaningful comparisons among sites, and improving functional understanding of lotic ecosystems.

The River Styles framework provides a geomorphological river characterization scheme in which assemblages of geomorphic units vary for differing River Styles, presenting differing arrays of aquatic habitat diversity for each style.

The ecological significance of the River Styles framework is tested by comparing the macroinvertebrate assemblages and habitat characteristics of pool and run geomorphic units for three different River Styles on the north coast of New South Wales, Australia.

Multivariate ordinations and analysis of similarity (ANOSIM) revealed that macroinvertebrate community structure differed between Bedrock‐Controlled Discontinuous Floodplain rivers and Gorge rivers, and between Bedrock‐Controlled Discontinuous Floodplain and Meandering Gravel Bed rivers, especially in pools. Differences between Gorge and Meandering Gravel Bed rivers were less apparent, largely due to variations within the Meandering Gravel Bed rivers group.

The variability in macroinvertebrate assemblage structure among geomorphic units was most strongly related to variability in substrate and hydraulic variables. Substrate composition differed significantly among all River Styles and geomorphic units, but other habitat variables showed few consistent differences among River Style groups.

These results suggest that the ecological similarity of macroinvertebrate communities within River Styles may presently be limited because some important large‐scale drivers of local habitat conditions are not included in River Styles designations. Integrating River Styles classification with other large‐scale variables reflecting stream size, temperature and hydrological regime may produce a process‐based physical classification capable of identifying river reaches with similar ecological structure and function.

Copyright © 2003 John Wiley & Sons, Ltd.
Testing taxonomic resolution levels for ecological monitoring in sandy beach macrobenthic communities
Authors: Defeo Omar , Lercari Diego
Published: January 2004

Sandy beaches are subject to a variety of human‐induced disturbances. However, very little is known about the consequences of disturbances on macroinfauna inhabiting these systems.

We evaluate the concepts of taxonomic and functional sufficiency and their potential applicability to cost‐effective assessment of environmental impacts on sandy beaches. To this end, we assess the effects of an artificial freshwater discharge on the macroinfauna inhabiting three sites of a sandy beach in Uruguay affected by a gradient of effect, using different taxonomic resolution levels.

Species abundance and biomass data were aggregated into family, class, phylum and functional feeding guilds; distance matrices between samples were constructed for every aggregation level. Non‐metric multidimensional scaling (NMDS), analysis of similarities (ANOSIM) and correlation between distance matrices from different levels of aggregation were used to explore the taxonomic resolution needed to detect the environmental impact.

The impact was detected at every aggregation level, including functional feeding guilds. Taxonomic resolution did not affect the outcome of the multivariate analyses, suggesting that higher taxonomic levels could be used to provide rapid responses for detecting ecological impacts in sandy beaches, or in cases with a lack of knowledge about community composition.

Even though NMDS with abundance data lost more information than with biomass as the taxonomic resolution decreased, it provided a better description of the short‐term succession in community structure at the site with intermediate disturbance.

Aggregation to higher taxonomic levels did not reduce the ability of ANOSIM to discriminate between sites. The large seasonal variations in community structure give strong support to recent findings that showed that sandy beach fauna is highly plastic and has a short‐term capacity for recovery from disturbances. Thus, we strongly suggest circumventing snapshot samplings in order to avoid misinterpretation of results arising from strong seasonal variations in community structure and abundance.

Copyright © 2003 John Wiley & Sons, Ltd.
Opportunistic observations of interactions between sperm whales and deep‐water trawlers based on sightings from fisheries observers in the northwest Atlantic
Authors: Karpouzli Evanthia , Leaper Russell
Published: January 2004

Cetacean observations were made by fisheries observers on trawlers targeting Greenland halibut (Reinhardtius hippoglossoides) in the area around the Flemish Cap, northwest Atlantic.

Data from four observers amounted to a total of 291 observer days at sea aboard fishing vessels. This effort was mainly concentrated in the periods July to September 1996 and February to April 1997.

Sperm whales (Physeter macrocephalus) were the most frequently sighted cetacean, with 82 encounters on 64 different days. Pilot whales were encountered on nine occasions.

Sighting rates of sperm whales during net hauling were significantly (approximately 30 times) greater than during shooting or steaming. Sperm whales were observed in aggregations of up to six animals close to the vessel and net during hauling. It is suggested that the sperm whales were attracted by the potential food source within the net, and possibly were feeding on fish escaping from the net. This represents rarely reported behaviour for this species.

Copyright © 2003 John Wiley & Sons, Ltd.