bluuebunny/crossref_metadata_2025 huggingface dataset:
Language-Related Activations in the Left Prefrontal Regions Are Differentially Modulated by Age, Proficiency, and Task Demands
Authors: Tatsuno Yoshinori , Sakai Kuniyoshi L.
Published: February 2005

It remains to be elucidated how cortical activations are modulated by factors of age, proficiency, and language task demands when mastering first language (L1) and a second language (L2). Using functional magnetic resonance imaging, we tested subjects aged 13 (the age 13 group) and 19 (the age 19 group), thereby comparing the cortical activations involved in past-tense verb identification with those involved in verb matching. We found that the activation in the dorsal triangular part of the left inferior frontal gyrus (IFG) was lower, corresponding to a higher proficiency in English (L2) in the older subjects, suggesting that the proficiency level plays a major role in the activation of this region during L2 acquisition. Moreover, the lower activation in the triangular and orbital parts of the left IFG (F3t/F3O) for the irregular past tense corresponding to a higher proficiency in L2, together with the nonsignificant activation for the regular past tense when its performance almost reached perfection for age 19, suggests that the modulation of the left F3t/F3O activation reflects language task demands for identifying correct past-tense forms. On the other hand, the left F3t/F3O activation in Japanese (L1) for age 13 was significantly greater than that for age 19, despite the matched performances in L1. These results suggest that the left IFG subserves language-specific functions that are critically required when mastering any language.
Small-Scale Molecular Motions Accomplish Glutamate Uptake in Human Glutamate Transporters
Authors: Koch Hans P. , Larsson H. Peter
Published: February 2005

Glutamate transporters remove glutamate from the synaptic cleft to maintain efficient synaptic communication between neurons and to prevent glutamate concentrations from reaching neurotoxic levels. Glutamate transporters play an important role in ischemic neuronal death during stroke and have been implicated in epilepsy and amytropic lateral sclerosis. However, the molecular structure and the glutamate-uptake mechanism of these transporters are not well understood. The most recent models of glutamate transporters have three or five subunits, each with eight transmembrane domains, and one or two membrane-inserted loops. Here, using fluorescence resonance energy transfer (FRET) analysis, we have determined the relative position of the extracellular regions of these domains. Our results are consistent with a trimeric glutamate transporter with a large (>45 Å) extracellular vestibule. In contrast to other transport proteins, our FRET measurements indicate that there are no large-scale motions in glutamate transporters and that glutamate uptake is accompanied by relatively small motions around the glutamate-binding sites. The large extracellular vestibule and the small-scale conformational changes could contribute to the fast kinetics predicted for glutamate transporters. Furthermore, we show that, despite the multimeric nature of glutamate transporters, the subunits function independently.
Activity-Dependent Long-Term Potentiation of Intrinsic Excitability in Hippocampal CA1 Pyramidal Neurons
Authors: Xu Jun , Kang Ning , Jiang Li , Nedergaard Maiken , Kang Jian
Published: February 2005

The efficiency of neural circuits is enhanced not only by increasing synaptic strength but also by increasing intrinsic excitability. In contrast to the detailed analysis of long-term potentiation (LTP), less attention has been given to activity-dependent changes in the intrinsic neuronal excitability. By stimulating hippocampal CA1 pyramidal neurons with synaptic inputs correlating with postsynaptic neuronal spikes, we elicited an LTP of intrinsic excitability (LTP-IE) concurring with synaptic LTP. LTP-IE was manifested as a decrease in the action potential threshold that was attributable to a hyperpolarized shift in the activation curve of voltage-gated sodium channels (VGSCs) rather than activity-dependent changes in synaptic inputs or A-type K+channels. Cell-attached patch recording of VGSC activities indicated such an activity-dependent change in VGSCs. Induction of LTP-IE was blocked by the NMDA receptor antagonist APV, intracellular BAPTA, the CaM kinase inhibitors KN-62 and autocamtide-2-related inhibitory peptide, and the protein synthesis inhibitors emetine and anisomycin. The results suggest that induction of LTP-IE shares a similar signaling pathway with the late phase of synaptic LTP and requires activation of the NMDA glutamate receptor subtype, Ca2+influx, activity of CaM kinase II, and function of the protein synthesis. This new form of hippocampal neuronal plasticity could be a cellular correlate of learning and memory besides synaptic LTP.
Spatial Exploration-InducedArcmRNA and Protein Expression: Evidence for Selective, Network-Specific Reactivation
Authors: Ramírez-Amaya Victor , Vazdarjanova Almira , Mikhael Dalia , Rosi Susanna , Worley Paul F. , Barnes Carol A.
Published: February 2005

The immediate-early geneArcis transcribed in neurons that are part of stable neural networks activated during spatial exploratory behaviors. Arc protein has been demonstrated to regulate AMPA-type glutamate receptor trafficking by recruiting endosomal pathways, suggesting a direct role in synaptic plasticity. The purpose of the present study is to examine the fidelity ofArcmRNA translation and the temporal dynamics of behaviorally induced Arc protein expression after rats explore a novel environment. These experiments reveal two waves of Arc protein expression after a single exploration session. In the initial wave, virtually all cells that express Arc mRNA in the hippocampus and parietal cortex also express Arc protein, indicating, at a cellular level, that mRNA transcription and translation are closely correlated from 30 min to 2 h in hippocampal CA and parietal neurons. A second wave of protein expression spans the interval from 8 to 24 h and is also remarkably specific to cells active in the original behavior-induced network. This second wave is detected in a subset of the original active network and displays the novel property that the proportions of Arc-positive neurons become correlated among regions at 24 h. This suggests that the second expression wave is driven by network activity, and the stabilization of circuits reflecting behavioral experience may occur in temporally discrete phases, as memories become consolidated. This is the first demonstration of network-selective translational events consequent to spatial behavior and suggests a role for immediate-early genes in circuit-specific, late-phase synaptic biology.
Quantitative1H Magnetic Resonance Spectroscopic Imaging Determines Therapeutic Immunization Efficacy in an Animal Model of Parkinson's Disease
Authors: Boska Michael D. , Lewis Travis B. , Destache Christopher J. , Benner Eric J. , Nelson Jay A. , Uberti Mariano , Mosley R. Lee , Gendelman Howard E.
Published: February 2005

Nigrostriatal degeneration, the pathological hallmark of Parkinson's disease (PD), is mirrored by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxication. MPTP-treated animals show the common behavioral, motor, and pathological features of human disease. We demonstrated previously that adoptive transfer of Copaxone (Cop-1) immune cells protected the nigrostriatal dopaminergic pathway in MPTP-intoxicated mice. Herein, we evaluated this protection by quantitative proton magnetic resonance spectroscopic imaging (1H MRSI).1H MRSI performed in MPTP-treated mice demonstrated thatN-acetyl aspartate (NAA) was significantly diminished in the substantia nigra pars compacta (SNpc) and striatum, regions most affected in human disease. When the same regions were coregistered with immunohistochemical stains for tyrosine hydroxylase, numbers of neuronal bodies and termini were similarly diminished. MPTP-intoxicated animals that received Cop-1 immune cells showed NAA levels, in the SNpc and striatum, nearly equivalent to PBS-treated animals. Moreover, adoptive transfer of immune cells from ovalbumin-immunized to MPTP-treated mice failed to alter NAA levels or protect dopaminergic neurons and their projections. These results demonstrate that1H MRSI can evaluate dopaminergic degeneration and its protection by Cop-1 immunization strategies. Most importantly, the results provide a monitoring system to assess therapeutic outcomes for PD.
Chemokine Signaling Guides Axons within the Retina in Zebrafish
Authors: Li Qin , Shirabe Komei , Thisse Christine , Thisse Bernard , Okamoto Hitoshi , Masai Ichiro , Kuwada John Y.
Published: February 2005

Chemokines are a large family of secreted proteins that play an important role in the migration of leukocytes during hematopoiesis and inflammation. Chemokines and their receptors are also widely distributed in the CNS. Although recent investigations are beginning to elucidate chemokine function within the CNS, relatively little is known about the CNS function of this important class of molecules. To better appreciate the CNS function of chemokines, the role of signaling by stromal cell-derived factor-1 (SDF-1) through its receptor, chemokine (CXC motif) receptor 4 (CXCR4), was analyzed in zebrafish embryos. The SDF-1/CXCR4 expression pattern suggested that SDF-1/CXCR4 signaling was important for guiding retinal ganglion cell axons within the retina to the optic stalk to exit the retina. Antisense knockdown of the ligand and/or receptor and a genetic CXCR4 mutation both induced retinal axons to follow aberrant pathways within the retina. Furthermore, retinal axons deviated from their normal pathway and extended to cells ectopically expressing SDF-1 within the retina. These data suggest that chemokine signaling is both necessary and sufficient for directing retinal growth cones within the retina.
Glucose-Dependent Insulinotropic Polypeptide Is Expressed in Adult Hippocampus and Induces Progenitor Cell Proliferation
Authors: Nyberg Jenny , Anderson Michelle F. , Meister Björn , Alborn Ann-Marie , Ström Anna-Karin , Brederlau Anke , Illerskog Ann-Christin , Nilsson Ola , Kieffer Timothy J. , Hietala Max Albert , Ricksten Anne , Eriksson Peter S.
Published: February 2005

The hippocampal dentate gyrus (DG) is an area of active proliferation and neurogenesis within the adult brain. The molecular events controlling adult cell genesis in the hippocampus essentially remain unknown. It has been reported previously that adult male and female rats from the strains Sprague Dawley (SD) and spontaneously hypertensive (SHR) have a marked difference in proliferation rates of cells in the hippocampal DG. To exploit this natural variability and identify potential regulators of cell genesis in the hippocampus, hippocampal gene expression from male SHR as well as male and female SD rats was analyzed using a cDNA array strategy. Hippocampal expression of the gene-encoding glucose-dependent insulinotropic polypeptide (GIP) varied strongly in parallel with cell-proliferation rates in the adult rat DG. Moreover, robust GIP immunoreactivity could be detected in the DG. The GIP receptor is expressed by cultured adult hippocampal progenitors and throughout the granule cell layer of the DG, including progenitor cells. Thus, these cells have the ability to respond to GIP. Indeed, exogenously delivered GIP induced proliferation of adult-derived hippocampal progenitorsin vivoas well asin vitro, and adult GIP receptor knock-out mice exhibit a significantly lower number of newborn cells in the hippocampal DG compared with wild-type mice. This investigation demonstrates the presence of GIP in the brain for the first time and provides evidence for a regulatory function for GIP in progenitor cell proliferation.
NADPH Oxidase-Derived Reactive Oxygen Species Mediate the Cerebrovascular Dysfunction Induced by the Amyloid β Peptide
Authors: Park Laibaik , Anrather Josef , Zhou Ping , Frys Kelly , Pitstick Rose , Younkin Steven , Carlson George A. , Iadecola Costantino
Published: February 2005

Overproduction of the amyloid β (Aβ) peptide is a key factor in the pathogenesis of Alzheimer's disease (AD), but the mechanisms of its pathogenic effects have not been defined. Patients with AD have cerebrovascular alterations attributable to the deleterious effects of Aβ on cerebral blood vessels. We report here that NADPH oxidase, the major source of free radicals in blood vessels, is responsible for the cerebrovascular dysregulation induced by Aβ. Thus, the free-radical production and the associated alterations in vasoregulation induced by Aβ are abrogated by the NADPH oxidase peptide inhibitor gp91ds-tat and are not observed in mice lacking the catalytic subunit of NADPH oxidase (gp91phox). Furthermore, oxidative stress and cerebrovascular dysfunction do not occur in transgenic mice overexpressing the amyloid precursor protein but lacking gp91phox. The mechanisms by which NADPH oxidase-derived radicals mediate the cerebrovascular dysfunction involve reduced bioavailability of nitric oxide. Thus, a gp91phox-containing NADPH oxidase is the critical link between Aβ and cerebrovascular dysfunction, which may underlie the alteration in cerebral blood flow regulation observed in AD patients.
Sodium Channels in Transient Retinal Bipolar Cells Enhance Visual Responses in Ganglion Cells
Authors: Ichinose Tomomi , Shields Colleen R. , Lukasiewicz Peter D.
Published: February 2005

Retinal bipolar cells are slow potential neurons that respond to photoreceptor inputs with graded potentials and do not fire action potentials. We found that transient ON bipolar cells recorded in retinal slices possess voltage-gated sodium channels located on either their dendrites or somas. The sodium currents in these neurons did not generate spikes but enhanced voltage responses evoked by visual stimulation, which selectively boosted transmission to transient ganglion cells. In contrast, sodium currents were not found in sustained ON bipolar cells, and light responses in sustained bipolar cells and ganglion cells were not affected by TTX. The presence of sodium channels in transient ON bipolar cells contributed to the separation of transient and sustained signals by selectively enhancing the responses of ON transient ganglion cells to light. Our results suggest that bipolar cell sodium channels augment transient signals and contribute to the temporal segregation of visual information.
Methanol and Ethanol Decomposition in Supercritical Water
Authors: Hack Walter , Masten David A. , Buelow Steven J.
Published: February 2005

The decomposition of CH3OH and C2H5OH in supercritical water was studied in a flow reactor tube (Ni/Mo/Cr/Fe alloy) in the temperature range 597 ≤ T/K ≤ 797 at a pressure of p = 315 bar for technical application of scH2O for hazardous chemical waste destruction. The CH3OH and C2H5OH concentrations in the liquid as a function of the residence times were determined by a Raman spectrometer.

The [CH3OH] and [C2H5OH] resp. decay followed first order kinetics and a rate constant k
1(653 K) = 1.3 × 10−2 s−1 for CH3OH and k
2(653 K) = 5.5 × 10−2 s−1 for C2H5OH was determined. The rate constant k
1 was found to be independent of the initial CH3OH concentration in the mass fraction range 0.002 ≤ x
m ≤ 0.04. The rate depended on the history of the reactor. Treatment with NH4OH, C2H5OH or with H2O2 at T = 653 K, did not change the rate. Treatment with HNO3/H2O2, however, at T = 838 K reduced the rate by about a factor of 1000.

The Arrhenius-activation energy over the above temperature range was determined to be E
A = 164 kJ/mol for methanol and E
A = 145 kJ/mol for ethanol.

The major products from methanol decomposition were CH4, H2, and CO2 as observed by gas chromatography and CH4 and CO2 by FTIR-spectrometry. No other products were found. The products were not effected by the pretreatment of the reactor wall. A non-radical mechanism, which explains the formation of only these products, will be discussed.
The Totally Symmetric Vibrations of NH3···HF and NH3···HCN: a CCSD(T) Study Including Anharmonicity Effects
Authors: Botschwina Peter , Oswald Rainer
Published: February 2005

The coupled cluster variant CCSD(T) has been employed to calculate potential energy and dipole moment surfaces for the hydrogen-bonded complexes NH3···HF and NH3···HCN, restricting the treatment to the totally symmetric coordinates. Both complexes have C
3ν symmetry, with equilibrium dissociation energies (D
e) predicted to be 52.1 and 27.1 kJ mol−1, respectively. Vibrational term energies and wavefunctions as well as absolute IR intensities are calculated under inclusion of anharmonicity effects. In contrast to previous theoretical work for NH3···HF, the umbrella bending vibration of this complex as well as for NH3···HCN is found to be rather anharmonic. The familiar double harmonic approximation fails to yield reliable values for the IR intensities of the NH3 (ND3) symmetric stretching vibrations of either NH3···HF or ND3···DF. The wavenumbers of the intermolecular stretching vibrations are predicted as ν4 = 277 cm−1 (NH3···HF) and ν5 = 154 cm−1 (NH3···HCN). Owing to a large quadratic coupling term in the electric dipole moment function, the band ν4(NH3···HF) has virtually zero intensity. The effects of deuterium substitution on wavenumbers and IR intensities have been studied for both complexes.
A Response-Time Approach for Estimating Sensitivity to Auditory Tempo Changes
Authors: Pouliot Marc , Grondin Simon
Published: February 2005

One of the features of the auditory system is its ability to efficiently process events that occur in rapid succession. The aim of the present study is to propose a new way of investigating sensitivity to auditory tempo changes. More specifically, it proposes to compare the relative sensitivity (bias) to acceleration and deceleration in both musical and monotonal conditions. Bias was measured with (1) a conventional psychophysical method known as the method of constant stimuli (MCS) and (2) a so-called method of dynamic stimuli (MDS). The latter method consists in responding with a finger press as soon as a near-continual tempo change is detected. With the MCS, there was no preference, as estimated by the point of subjective equality, between acceleration and deceleration in the monotonal condition, but there was a preference in the musical condition that indicated more facility for estimating decelerations than accelerations. The results obtained with the MDS are consistent with the MCS results, given that the response time was faster for decelerations than accelerations in the musical condition but not in the monotonal condition. We conclude that the MDS is a sensitive tool for investigating slight tempo variations.
The Influence of Pitch Interval on the Perception of Polyrhythms
Authors: Moelants Dirk , van Noorden Leon
Published: February 2005

Research by S. Handel and J. S. Oshinsky (1981) has shown that when tapping to polyrhythms, people synchronize with different subsequences depending on the overall tempo, with a global change from the faster component at slow tempi to the slower component at medium tempi and then to the overall repeating pattern at fast tempi. In this article, similar polyrhythmic patterns are studied, adding larger pitch intervals between the two sequences. The results largely confirm the findings of Handel and Oshinsky at small pitch intervals, but at larger pitch intervals, the importance of the overall pattern decreases in favor of the slow component of the polyrhythm. This effect can be explained by the increased possibility for streaming of the two components and the decrease in peripheral interaction of the coinciding tones. The results of the experiment are modeled following the resonance model for temporal selectivity proposed by L. Van Noorden and D. Moelants (1999). The preference for certain subsequences can be explained as a resonance phenomenon with a natural frequency of 2 Hz.
Interval Timing in Spoken Lists of Words
Authors: Cummins Fred
Published: February 2005

Isochronous interval production with discrete motor responses has been studied most intensively by using well-practiced tapping in a synchronization/continuation paradigm. Somewhat fewer studies have examined the timing of shorter sequences of intervals that may be susceptible to metrical grouping. I here look at the attempted isochronous production of lists of eight trochees and examine the resulting interval patterns both in terms of the Wing-Kristofferson model (A. M. Wing & A. B. Kristofferson, 1973) and Rosenbaum�s hierarchical timing model (D. A. Rosenbaum, S. B. Kenny, & M. A. Derr, 1983). In Experiment 1, readings are self- paced and done under conditions of uncertainty. The Wing-Kristofferson model is not applicable to the data, which more closely resemble data exhibiting hierarchical control of intervals. In Experiment 2, readings are paced, well-practiced, and done without uncertainty. Neither Wing and Kristofferson�s model nor Rosenbaum�s model adequately captures the serial dependencies observed, although under these conditions variability is greatly reduced. In both experiments, there are dependencies between nonadjacent intervals that neither model can yet account for.
Gamma-Band Responses to Perturbed Auditory Sequences: Evidence for Synchronization of Perceptual Processes
Authors: Zanto Theodore P. , Large Edward W. , Fuchs Armin , Kelso J. A. Scott
Published: February 2005

We measured modulations of neuroelectric gamma-band activity (GBA) as subjects listened to isochronous pure-tone sequences with embedded temporal perturbations. Perturbations occurred every 6�10 tones, and at the locus of the perturbation, tones occurred early, on time, or late. In the absence of perturbations, induced (non�phase-locked) GBA reached maximum power simultaneously with the occurrence of tone onsets, whereas evoked (phase-locked) GBA peaks were observed after onsets. During late perturbation trials, peaks in induced activity tended to precede tone onsets, and during early perturbation trials, induced peaks followed tone onsets. Induced peaks returned to synchrony after both types of perturbations. Early tones resulted in a marked increase in evoked GBA power at the locus of the perturbation. The latency of evoked GBA relative to tone onset, as well as some other features of the response, depended asymmetrically on the direction of the perturbation. The current results provide evidence for the synchronization of GBA during the perception of auditory rhythms, thus supporting the role of GBA in temporal expectancy.
Pediatric Fabry Disease
Authors: Ries Markus , Gupta Surya , Moore David F. , Sachdev Vandana , Quirk Jane M. , Murray Gary J. , Rosing Douglas R. , Robinson Chevalia , Schaefer Ellen , Gal Andreas , Dambrosia James M. , Garman Scott C. , Brady Roscoe O. , Schiffmann Raphael
Published: February 2005

Background. Fabry disease is an underdiagnosed, treatable, X-linked, multisystem disorder.

Objectives. To test the hypothesis that quality of life and sweating are decreased among pediatric patients with Fabry disease, compared with control subjects, and to provide quantitative natural history data and novel clinical end points for therapeutic trials.

Design. Prospective, cross-sectional, observational study.

Setting. Referral to the National Institutes of Health.

Participants. Twenty-five male children with Fabry disease (mean age: 12.3 ± 3.5 years) and 21 age-matched control subjects.

Main Outcome Measures. Quality of life (measured with the Child Health Questionnaire) and sweating (assessed with the quantitative sudomotor axon reflex test).

Results. Quality of life scores for pediatric patients <10 years of age with Fabry disease, compared with published normative values, were 55 ± 17 vs 83 ± 19 for bodily pain and 62 ± 19 vs 80 ± 13 for mental health. Bodily pain scores for patients ≥10 years of age were 54 ± 22 vs 74 ± 23. Sweat volume in the Fabry disease group was 0.41 ± 0.46 μL/mm2, compared with 0.65 ± 0.44 μL/mm2 in the control group. Renal function, urinary protein excretion, and cardiac function and structure were normal for the majority of patients. The 3 patients with residual α-galactosidase A activity ≥1.5% of normal values were free of cornea verticillata and had normal serum and urinary globotriaosylceramide levels. All other children had glycolipid levels comparable to those of adult patients with Fabry disease. Acroparesthesia and cardiac abnormalities were generally present before anhidrosis and proteinuria. Mapping of the missense mutations on the crystallographic structure of α-galactosidase A revealed that the mutations were partially surface-exposed and distal to the active site among individuals with residual enzyme activity. Mutations associated with left ventricular hypertrophy (defined as left ventricular mass index of >51 g/m2.7) were localized near the catalytic site of the enzyme.

Conclusions. Despite the absence of major organ dysfunction, Fabry disease demonstrates significant morbidity already in childhood. We have identified important, potentially correctable or preventable, outcome measures for future therapeutic trials. Prevention of complications involving major organs should be the goal for long-term specific therapy.
Robust adaptive control for uncertain time‐delay systems
Authors: Hua Changchun , Guan Xinping , Shi Peng
Published: February 2005

The problem of robust stabilization for uncertain dynamic time‐delay systems is considered. Firstly a class of time‐delay systems with uncertainties bounded by high‐order polynomials and unknown coefficients are considered. The corresponding controller is designed by employing adaptive method. It is shown that the controller designed can render the closed‐loop system uniformly ultimately bounded stable based on Lyapunov–Krasovskii method and Lyapunov stability theory. Then the proposed adaptive idea is applied to stabilizing a class of large‐scale time‐delay systems with strong interconnections. A decentralized feedback adaptive controller is designed which guarantees the closed‐loop large‐scale systems uniformly ultimately bounded stable. Finally, numerical examples are given to show the potential of the proposed techniques. Copyright © 2005 John Wiley & Sons, Ltd.
Terrain Vague: Interactive Space and the Housescape
Authors: Weinstock Mike
Published: February 2005

‘Only connect!’ Despite the proliferation of interactivity technologies for domestic spaces, current commercial models for the smart house remain focused on the supply of gizmos and multimedia flatscreens. What is the design potential for connectivity in the home? Mike Weinstock asks how interactive technologies might achieve a new level of topographical and environmental change and enhance the spaces in which we live. Copyright © 2005 John Wiley & Sons, Ltd.
“There has always been a relationship between design and technology”: Ron Arad on Interactivity and Low‐Res Design
Authors: Bullivant Lucy
Published: February 2005

Best Known for his tactile and colourful furniture designs, Ron Arad also experiments with multimedia technologies in his interactive installation and built work. Lucy Bullivant talks to Arad and discovers how he transfers the pleasures of one medium over to another: his impulse to ‘bounce’ physical objects such as his tempered steel ‘rolling shells’, translating into low‐res interactive responses on demand – a technological tactility. Copyright © 2005 John Wiley & Sons, Ltd.
Lighter Living in the 21st Century: FjordParken Himmerland and Marina Fjordparken, Egholm, Denmark
Authors: Briginshaw Jane
Published: February 2005

Jane Briginshaw visits a housing scheme in northern Jutland, where the use of timber has tackled concrete's stranglehold over the Danish building industry. A mixed‐used scheme, providing social housing and provision for a local cooperative of the marina's sailing‐club members, it caters in its internal planning to occupants' needs. Despite being architecturally accomplished, is its cool anonymity devoid of the ‘wow’ factor that Brits are starting to expect from newbuild? Copyright © 2005 John Wiley & Sons, Ltd.
The Submarine on the Hill
Authors: Heathcote David , Barr Sue
Published: February 2005

Our intrepid autotravellers, David Heathcote and Sue Barr, continue their quest across Europe in search of that illusive holy grail – the 1970s house. They remain undeterred, or almost, by the number that are hidden and shuttered, with absentee owners. Copyright © 2005 John Wiley & Sons, Ltd.
Architecture, Liquid, Gas
Authors: Bouman Ole
Published: February 2005

Wireless, embedded communication technologies with their emphasis on human connectivity rather than the networking of place to place, no longer require the interface of bricks and mortar. Ole Bouman discusses the implications of this for architecture in an age in which people rather than place become the interface. He also describes how his own curatorial work has, in recent years, engaged with time‐based rather than location‐based technologies. Copyright © 2005 John Wiley & Sons, Ltd.
Interactivity at the Centre of Avant‐Garde Architectural Research
Authors: Saggio Antonino
Published: February 2005

The onset of digital technologies is often cited as the determining force behind the recent paradigm shift in architecture. Here, Antonino Saggio makes the case for interactivity. He argues that it is interactivity rather than hardware or software that has been the essential catalyst, providing the fundamental precepts underlying contemporary communications and bringing with it a new configuring of relationships in which the subject takes centre stage and shifts the object to the periphery. Copyright © 2005 John Wiley & Sons, Ltd.
Nanoporous Ultra‐Low‐Dielectric‐Constant Fluoropolymer Films via Selective UV Decomposition of Poly(pentafluorostyrene)‐block‐Poly(methyl methacrylate) Copolymers Prepared Using Atom Transfer Radical Polymerization
Authors: Fu G.‐D. , Yuan Z. , Kang E.‐T. , Neoh K.‐G. , Lai D. M. , Huan A. C. H.
Published: February 2005

Block copolymers of poly(pentafluorostyrene) (PFS) and poly(methyl methacrylate) (PMMA) (PFS‐b‐PMMA) have been synthesized using atom transfer radical polymerization (ATRP). Then, nanoporous fluoropolymer films have been prepared via selective UV decomposition of the PMMA blocks in the PFS‐b‐PMMA copolymer films. The chemical composition and structure of the PFS homopolymers and copolymers have been characterized using nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis (TGA), X‐ray photoelectron spectroscopy (XPS), time‐of‐flight secondary‐ion mass spectrometry (ToF‐SIMS), and molecular‐weight measurements. The cross‐sectional and surface morphologies of the PFS‐b‐PMMA copolymer films before and after selective UV decomposition of the PMMA blocks have been studied using field‐emission scanning electron microscopy (FESEM). The nanoporous fluoropolymer films with pore sizes in the range 30–50 nm and porosity in the range 15–40 % have been obtained from the PFS‐b‐PMMA copolymers of different PMMA content. Dielectric constants approaching 1.8 have been achieved in the nanoporous fluoropolymer films which contain almost completely decomposed PMMA blocks.
Novel Conjugated Organic Dyes for Efficient Dye‐Sensitized Solar Cells
Authors: Hara K. , Sato T. , Katoh R. , Furube A. , Yoshihara T. , Murai M. , Kurashige M. , Ito S. , Shinpo A. , Suga S. , Arakawa H.
Published: February 2005

Novel conjugated organic dyes that have N,N‐dimethylaniline (DMA) moieties as the electron donor and a cyanoacetic acid (CAA) moiety as the electron acceptor were developed for use in dye‐sensitized nanocrystalline‐TiO2 solar cells (DSSCs). We attained a maximum solar‐energy‐to‐electricity conversion efficiency (η) of 6.8 % under AM 1.5 irradiation (100 mW cm–2) with a DSSC based on 2‐cyano‐7,7‐bis(4‐dimethylamino‐phenyl)hepta‐2,4,6‐trienoic acid (NKX‐2569): short‐circuit photocurrent density (Jsc) = 12.9 mA cm–2, open‐circuit voltage (Voc) = 0.71 V, and fill factor (ff) = 0.74. The high performance of the solar cells indicated that highly efficient electron injection from the excited dyes to the conduction band of TiO2 occurred. The experimental and calculated Fourier‐transform infrared (FT‐IR) absorption spectra clearly showed that these dyes were adsorbed on the TiO2 surface with the carboxylate coordination form. A molecular‐orbital calculation indicated that the electron distribution moved from the DMA moiety to the CAA moiety by photoexcitation of the dye.
Single‐Source Precursors For Synthesizing Bifunctional Periodic Mesoporous Organosilicas
Authors: Hunks W. J. , Ozin G. A.
Published: February 2005

A new class of bifunctional periodic mesoporous organosilicas (PMOs) composed of organosilicate building blocks with two different silicon sites have been synthesized from the single‐source bifunctional organosilica precursors tris(triethoxysilylethyl)ethoxysilane and bis(triethoxysilylethyl)diethoxysilane, respectively denoted MT3‐PMO and DT2‐PMO. The synthesis of these PMOs is achieved by the co‐assembly of a triblock‐copolymer Pluronic P123 template with the bifunctional organosilica precursor under acid‐catalyzed and inorganic‐salt‐assisted conditions. After template removal through solvent extraction, the MT3‐PMO and DT2‐PMO so obtained show well‐ordered mesopores and display large pore diameters (6–7 nm) and pore volumes (0.6–0.8 cm3 g–1) with a narrow pore‐size distribution and high surface areas (700–800 m3 g–1).
First Microwave‐Accelerated Hiyama Coupling of Aryl‐ and Vinylsiloxane Derivatives: Clean Cross‐Coupling of Aryl Chlorides within Minutes
Authors: Clarke Matthew L
Published: February 2005

The first microwave‐accelerated Hiyama cross‐coupling reactions are reported. The reactions of aryl bromides and activated aryl chlorides with PhSi(OMe)3 [or C2H3Si(OMe)3] are complete within minutes using a modified catalyst system that can be prepared from commercially available reagents in situ. The microwave‐accelerated reactions proceed under relatively mild conditions (110–115 °C)
Monolithic Disk‐Supported Metathesis Catalysts for Use in Combinatorial Chemistry
Authors: Mayr Monika , Wang Dongren , Kröll Roswitha , Schuler Norbert , Prühs Stefan , Fürstner Alois , Buchmeiser Michael R.
Published: February 2005

Two metathesis catalysts, RuCl2(PCy3)(NHC)(CHPh) (1) [NHC=1‐(2,4,5‐trimethylphenyl)‐3‐(6‐hydroxyhexyl)‐imidazol‐2‐ylidene] and Mo(N‐2,6‐i‐Pr2‐C6H3)(CHCMe2Ph)(BIPHEN) (2) [BIPHEN=(R)‐3,3′‐di‐t‐butyl‐5,5′,6,6′‐tetramethyl‐2,2′‐biphenolate) have been immobilized on polymeric, monolithic discs using a “grafting from” protocol. Monolithic discs were prepared via ring‐opening metathesis polymerization (ROMP) from norborn‐2‐ene (NBE), tris(norborn‐5‐ene‐2‐ylmethyleneoxy)methylsilane [(NBE‐CH2O)3‐SiCH3], 2‐propanol, toluene and RuCl2(PCy3)2(CHPh). Catalyst loadings of 0.55 and 0.7 wt %, respectively, were obtained. Monolithic disc‐immobilized 1 was used in various metathesis‐based reactions including ring‐closing metathesis (RCM), ring‐opening cross metathesis and enyne metathesis. Using 0.23–0.59 mol % of supported 1, turnover numbers (TONs) up to 330 were achieved. Monolithic disc‐immobilized 2 was used in various enantioselective RCM and desymmetrization reactions. Using 9–13 mol % of supported catalyst, excellent yields up to 100% and high enantiomeric excess (ee≤88%) were observed. In both cases, metal leaching was low (≤3 and ≤2%, respectively). In addition, 1 catalyzed the cyclopolymerization of diethyl dipropargylmalonate (DEDPM) to yield poly(ene)s consisting of 5‐membered rings, i.e., cyclopent‐1‐ene‐1‐vinylene units. The polymerization proceeded via non‐stoichiometric initiation yielding polymers with unimodal molecular weight distribution. Using a catalyst to monomer ratio of 1 : 170, molecular weights of Mw=16,400 and Mn=11,700 g/mol, PDI=1.40 were obtained.
Transition Metal‐Catalyzed Asymmetric Hydroamination of Alkenes (AHA)
Authors: Hultzsch Kai C.
Published: February 2005

The hydroamination of unsaturated carbon‐carbon linkages allows a facile and highly atom‐economical access to industrially relevant nitrogen‐containing basic and fine chemicals as well as naturally occurring alkaloid skeletons. Significant research efforts have led to the development of efficient catalyst systems for intra‐ and intermolecular hydroamination reactions. Of particular interest are hydroaminations promoted by chiral catalysts, in which a new chiral center is generated or chiral substrates are kinetically resolved. This review will give an overview on the current state of the art in this rapidly evolving field of catalysis.
Cobalt(II)‐Azabis(oxazoline)‐Catalyzed Conjugate Reduction of α,β‐Unsaturated Carbonyl Compounds
Authors: Geiger Christian , Kreitmeier Peter , Reiser Oliver
Published: February 2005

Azabis(oxazolines) prove to be superior ligands for the enantioselective, cobalt(II)‐catalyzed conjugate reduction of α,β‐unsaturated carbonyl compounds with sodium borohydride. β‐Trisubstituted α,β‐unsaturated esters and amides as well as γ‐butenolides are readily converted to their corresponding saturated counterparts with enantioselectivities up to 97% ee.
Synthesis of Coumarins in a Molten n‐Bu4NOAc/n‐Bu4NBr Mixture through a Domino Heck Reaction/Cyclization Process
Authors: Battistuzzi Gianfranco , Cacchi Sandro , De Salve Ilse , Fabrizi Giancarlo , Parisi Luca M.
Published: February 2005

4‐Arylcoumarins can be prepared in good to high yields by reacting readily available methyl or butyl 3‐(o‐hydroxyaryl)acrylates with aryl iodides and bromides in an n‐Bu4NOAc/n‐Bu4NBr mixture at 100 °C in the presence of Pd(OAc)2.
Rationalisation of Solvent Effects in the DielsAlder Reaction Between Cyclopentadiene and Methyl Acrylate in Room Temperature Ionic Liquids
Authors: Vidiš Ana , Ohlin C. André , Laurenczy Gábor , Küsters Ernst , Sedelmeier Gottfried , Dyson Paul J.
Published: February 2005

The Diels–Alder reaction between cyclopentadiene and methyl acrylate in ionic liquids has been studied in detail. The effect of contamination of the ionic liquids by common impurities, viz. sodium and chloride ions, and water, on the selectivity has been investigated. The presence of high concentrations of chloride was found to decrease the selectivity. Anion and, in particular, cation effects have been investigated using an extensive series of air‐stable room temperature ionic liquids, and kinetic parameters have been determined. It has been found that strongly interacting groups, particularly electrophilic moieties on the cation, accelerate the formation of the endo products. Substrate solubility intimately connected to the selectivity was found to be mainly anion dependent. An NMR‐based solvent parameter scale and semi‐empirical models are used to analyse the results and provide a tool for the prediction of selectivities in ionic liquids.
Optimal production and scheduling of a process with decaying catalyst
Authors: Bizet Véronique M. , Grossmann Ignacio E. , Juhasz Nikola M.
Published: February 2005

A multiperiod mixed‐integer nonlinear programming (MINLP) optimization model is presented to schedule catalyst changeovers and determine the best operating policy for a chemical process with decaying performance. Two solution strategies are proposed to reduce the effect of nonconvexities and to reduce the solution time: (1) a search strategy that relies on partitioning the time horizon and (2) a strategy that makes use of the Generalized Benders Decomposition (GBD). Examples are presented for different time horizons to illustrate the performance of the proposed methods. The same objective value is reached with both strategies, which find better solutions than the full‐space MINLP. For small models, the GBD algorithm is faster than the partitioning search strategy, whereas the latter method is faster for larger models. Comparison with the operating strategy used in a real plant is also presented. © 2005 American Institute of Chemical Engineers AIChE J, 51:909–921, 2005
Optimal transition and robust control design for exothermic continuous reactors
Authors: Flores‐Tlacuahuac Antonio , Alvarez Jesús , Saldívar‐Guerra Enrique , Oaxaca Guillermo
Published: February 2005

The problem of jointly designing the optimal steady‐state transition and the related tracking controller for a representative class of exothermic continuous chemical reactors is addressed. The combination of optimal, constructive, and conventional control ideas yields a design methodology with: the identification of the underlying solvability conditions with physical meaning, the construction of the optimal transition, a controller to robustly perform the associated tracking task, and a closed‐loop stability criterion coupled with conventional‐like tuning guidelines. The controller is driven by a temperature measurement, simultaneously manipulates the heat exchange and reactant feed rates, and its implementation does not require the chemical kinetics model. The control scheme consists of a decentralized feedforward–feedback temperature loop and a ratio‐type reactant dosage controller. The proposed transition and control design approach is illustrated with an application example treated with numerical simulations. © 2005 American Institute of Chemical Engineers; AIChE J, 51: 895–908, 2005.
Recursive estimation in constrained nonlinear dynamical systems
Authors: Vachhani Pramod , Rengaswamy Raghunathan , Gangwal Vikrant , Narasimhan Shankar
Published: February 2005

In any modern chemical plant or refinery, process operation and the quality of product depend on the reliability of data used for process monitoring and control. The task of improving the quality of data to be consistent with material and energy balances is called reconciliation. Because chemical processes often operate dynamically in nonlinear regimes, techniques such as extended‐Kalman filter (EKF) and nonlinear dynamic data reconciliation (NDDR) have been developed for reconciliation. There are various issues that arise with the use of either of these techniques. EKF cannot handle inequality or equality constraints, whereas the NDDR has high computational cost. Therefore, a more efficient and robust method is required for reconciling process measurements and estimating parameters involved in nonlinear dynamic processes. Two solution techniques are presented: recursive nonlinear dynamic data reconciliation (RNDDR) and a combined predictor–corrector optimization (CPCO) method for efficient state and parameter estimation in nonlinear systems. The proposed approaches combine the efficiency of EKF and the ability of NDDR to handle algebraic inequality and equality constraints. Moreover, the CPCO technique allows deterministic parameter variation, thus relaxing another restriction of EKF where the parameter changes are modeled through a discrete stochastic equation. The proposed techniques are compared against the EKF and the NDDR formulations through simulation studies on a continuous stirred tank reactor and a polymerization reactor. In general, the RNDDR performs as well as the two traditional approaches, whereas the CPCO formulation provides more accurate results than RNDDR at a marginal increase in computational cost. © 2005 American Institute of Chemical Engineers AIChE J, 51: 946–959, 2005
Increased biofilm activity in BGAC reactors
Authors: Herzberg Moshe , Dosoretz Carlos G. , Green Michal
Published: February 2005

In bioreactors systems granulated activated carbon (GAC) was proven to be an advantageous biofilm carrier over inert media with similar physical properties (nonadsorbing carbon) under conditions of pollutant partial penetration in the biofilm. Results from laboratory experiments using atrazine degrading bacteria (Pseudomonas ADP) and modeling assuming GAC adsorption/desorption mechanism, showed higher atrazine degradation rate resulting in better effluent quality in the biofilm granulated activated carbon (BGAC) reactor. Increased biofilm activity due to the double flux of substrate from the bulk liquid and from the GAC can explain the better performance of the BGAC reactor. © 2005 American Institute of Chemical Engineers AIChE J, 51: 1042–1047, 2005
Concentration enrichment in confined, gradient energy systems
Authors: Kosto Timothy J. , Nauman E. Bruce
Published: February 2005

The enrichment or depletion of components near bounding surfaces in confined geometries was estimated using the generalized chemical potential for a molecule in a binary mixture. The chemical potential depends on concentration gradients and the local concentrations. Mean‐field–based parameter estimates were combined with regular solution thermodynamics to calculate the enrichment of the favored component near an attractive bounding surface in confined geometries arising from weak van der Waals attractions. Partition coefficients from 2 to 3000 were calculated for pores of small but realistic diameter in contact with a reservoir of the binary mixture. Critical wetting transitions, like those reported for unconfined systems, occurred in confined pores. In such a transition, the material inside is near the upper binodal concentration when the reservoir concentration is below the lower binodal. The corresponding partition coefficient is then very large; appreciable concentration enrichment occurs even in pores that do not exhibit wetting transitions. © 2005 American Institute of Chemical Engineers AIChE J, 51: 1032–1041, 2005
Support for association between ADHD and two candidate genes: NET1 and DRD1
Authors: Bobb Aaron J. , Addington Anjene M. , Sidransky Ellen , Gornick Michele C. , Lerch Jason P. , Greenstein Deanna K. , Clasen Liv S. , Sharp Wendy S. , Inoff‐Germain Gale , Wavrant‐De Vrièze Fabienne , Arcos‐Burgos Mauricio , Straub Richard E. , Hardy John A. , Castellanos F. Xavier , Rapoport Judith L.
Published: February 2005

Attention deficit hyperactivity disorder (ADHD) is a common, multifactorial disorder with significant genetic contribution. Multiple candidate genes have been studied in ADHD, including the norepinephrine transporter (NET1) and dopamine D1 receptor (DRD1). NET1 is implicated in ADHD because of the efficacy of atomoxetine, a selective noradrenergic reuptake inhibitor, in the treatment of ADHD. DRD1 is primarily implicated through mouse models of ADHD. DNA from 163 ADHD probands, 192 parents, and 129 healthy controls was used to investigate possible associations between ADHD and polymorphisms in 12 previously studied candidate genes (5‐HT1B, 5‐HT2A, 5‐HT2C, ADRA2A, CHRNA4, COMT, DAT1, DRD1, DRD4, DRD5, NET1, and SNAP‐25). Analyses included case‐control and family‐based methods, and dimensional measures of behavior, cognition, and anatomic brain magnetic resonance imaging (MRI). Of the 12 genes examined, two showed a significant association with ADHD. Transmission disequilibrium test (TDT) analysis revealed significant association of two NET1 single nucleotide polymorphisms (SNPs) with ADHD (P ≤ 0.009); case‐control analysis revealed significant association of two DRD1 SNPs with ADHD (P ≤ 0.008). No behavioral, cognitive, or brain MRI volume measurement significantly differed across NET1 or DRD1 genotypes at an alpha of 0.01. This study provides support for an association between ADHD and polymorphisms in both NET1 and DRD1; polymorphisms in ten other candidate genes were not associated with ADHD. Because family‐based and case‐control methods gave divergent results, both should be used in genetic studies of ADHD. © 2005 Wiley‐Liss, Inc.
Crystallographic report: [N,N‐Methylethylaminopropylalane]2
Authors: Hecht Elmar
Published: February 2005

Dimeric and centrosymmetric [MeEtN(CH2)3AlH2]2 comprises aluminum centers, coordinated in a distorted trigonal bipyramidal fashion by three hydrogen atoms, one nitrogen atom and one carbon atom. The aluminum atoms are bridged by hydrogen atoms, creating a planar, four‐membered Al2H2 ring. Copyright © 2005 John Wiley & Sons, Ltd.