bluuebunny/crossref_metadata_2025_split huggingface dataset:
Signal Detection Theory
Authors: MacMillan Neil A. 
Published: November 2003

AbstractIn perceptual, cognitive, and diagnostic tasks, accuracy depends on both limited sensitivity and the application of a decision process. By making explicit assumptions about the nature of the cognitive representation, signal detection theory (SDT) measures the contributions of these two components of performance. (Other approaches to assessing accuracy also constrain possible representations, although not all are explicit about their assumptions.) Thereceiver‐operating characteristic(ROC) curve, which takes account of response bias in decision‐making by examining conditions in which this bias varies, is a valuable tool for sensitivity measurement: The ROC curve provides an assumption‐free index of accuracy, and is also used to distinguish among competing representations. The simplest form of SDT assumes that different stimulus possibilities lead to distributions of strength on a decision axis, and this model can be applied to many experimental paradigms in which a single stimulus is presented on each trial. Using more complex representations in which distributions lie in a multidimensional space, SDT predicts the relation between different paradigms for measuring accuracy (e.g., two‐alternative forced‐choice, same‐different). Multidimensional representations also describe the classification and identification of stimuli from complex stimulus sets, and are particularly useful in analyses of perceptual interaction and attention.
Parallel and Serial Processing
Authors: Logan Gordon D. 
Published: November 2003

AbstractThis chapter reviews theoretical and empirical progress that has been made in answering the question “Is processing parallel or serial?” Answers to the question are complicated because the distinction between parallel and serial processing interacts with other basic distinctions, including exhaustive versus self‐terminating search, limited versus unlimited capacity, discrete versus continuous processing, and stochastic versus functional independence. Because of these complications, parallel and serial models readily mimic each other's predictions. Empirical answers to the question are complicated as well because different procedures invoke parallel and serial processing in different ways, and because detailed theories of empirical phenomena often mimic each other's predictions. The chapter reviews progress in distinguishing parallel and serial models of memory search, visual search, dual‐task performance, redundant stimulation, and memory retrieval. It addresses recent alternatives to parallel processing, such as coactivation and mixture models. It ends by evaluating the amount of cumulative progress that has been made in answering the question “Is processing parallel or serial?” and by speculating about prospects for progress in the future.
Aging and Cognition
Authors: Rabbitt Patrick 
Published: November 2003

AbstractAging is indexed both by the passage of time and as the progress of biological processes occurring in time. Biological aging can be indexed by time related physiological change in sensory and motor function that directly affect cognitive competence and also act as markers for changes in the brain and central nervous system, and so in mental abilities. Cognitive and biological changes can be studied either by cross‐sectional or by longitudinal comparisons, both of which have logical and methodological advantages and difficulties. The simplicity of applied studies to understand and mitigate practical difficulties that older people encounter in their daily lives contrasts with the methodological difficulties of studies driven by contrasting general theories of cognitive aging. One, logically questionable, assumption has been that changes are driven by “global” and diffuse brain changes that modify a particular master performance parameter, such as general mental ability or information processing speed, and so affect all cognitive systems to the same extent. An alternative assumption, that aging affects some brain systems, particularly those in the frontal and prefrontal cortex that control “executive” behavior earlier and more severely than others, is better supported by logic and evidence, but encounters methodological problems in relating behavioral to neurophysiological changes.
The Effects of Material Properties on the Activity of Sol‐Gel Entrapped Perruthenate under Supercritical Conditions
Authors: Ciriminna Rosaria , Campestrini Sandro , Pagliaro Mario 
Published: November 2003

AbstractSilica gels organically modified and doped with the ruthenium species tetra‐n‐propylammonium perruthenate (TPAP) are leach‐proof, selective catalysts for the aerobic oxidation of alcohols to carbonyl compounds with dioxygen at low pressure in compressed carbon dioxide. The catalytic sol‐gels are recyclable and the correlation between the reactivity of the materials and their surface polarity and textural properties suggests valuable information on the chemical behaviour of sol‐gel entrapped silica catalysts in oxidation catalysis which is of relevant interest considering the importance of heterogeneous oxidative dehydrogenation of alcohols in fine chemistry. An explanation of the structure‐activity relationship is proposed to provide guidelines for the further development of efficient solid oxidation catalysts for conversions in supercritical carbon dioxide.
Heterogeneous Enantioselective Hydrogenation of Activated Ketones Catalyzed by Modified Pt‐Catalysts: A Systematic Structure‐Selectivity Study
Authors: Exner Christian , Pfaltz Andreas , Studer Martin , Blaser Hans‐Ulrich 
Published: November 2003

AbstractA systematic structure‐selectivity study was carried out for the enantioselective hydrogenation of activated ketones with chirally modified Pt/Al2O3 catalysts. For this, 18 modifiers containing an extended aromatic system able to form a strong adsorption complex with the Pt surface, and a suitable chiral group with an amino function capable to interact with the keto group of the substrate (HCd, Qd, HCn, Qn, and semi‐synthetic derivatives, as well as synthetic analogues) were prepared and tested on 8 different activated ketones in AcOH and toluene under standard conditions. It was found that relatively small structural changes of the substrate and/or modifier structures strongly affected the enantioselectivity, and that no “best” modifier exists for all substrates. The highest ees for all substrates were obtained with quinuclidine‐derived modifiers in combination with naphthalene or quinoline rings, either in AcOH (substrates 1–5 and 8, all carrying an sp3 carbon next to the keto group) or toluene (6 and 7, with an sp2 carbon next to the ketone). The presence and nature of the substituent R' at the quinuclidine significantly affected the ee (positive and negative effects). Certain combinations of an aromatic system and an amino function were preferred: For the quinuclidine moiety, quinoline and to a somewhat lesser extent naphthalene were a better match, while for the pyrrolidinylmethyl group anthracene was better suited. Methylation of the OH group often had a positive effect for hydrogenations in AcOH but not in toluene. With the exception of 8, higher ees were obtained for the Cd/Qn series [leading to (R)‐products] than for the Cn/Qd series [leading to (S)‐products]. In several cases, opposite structure‐selectivity trends were detected when comparing reactions in toluene and AcOH, indicating a significant influence of the solvent.
Chloride channels as tools for developing selective insecticides
Authors: Bloomquist Jeffrey R. 
Published: November 2003

AbstractLigand‐gated chloride channels underlie inhibition in excitable membranes and are proven target sites for insecticides. The γ‐aminobutyric acid (GABA1) receptor/chloride ionophore complex is the primary site of action for a number of currently used insecticides, such as lindane, endosulfan, and fipronil. These compounds act as antagonists by stabilizing nonconducting conformations of the chloride channel. Blockage of the GABA‐gated chloride channel reduces neuronal inhibition, which leads to hyperexcitation of the central nervous system, convulsions, and death. We recently investigated the mode of action of the silphinenes, plant‐derived natural compounds that structurally resemble picrotoxinin. These materials antagonize the action of GABA on insect neurons and block GABA‐mediated chloride uptake into mouse brain synaptoneurosomes in a noncompetitive manner. In mammals, avermectins have a blocking action on the GABA‐gated chloride channel consistent with a coarse tremor, whereas at longer times and higher concentrations, activation of the channel suppresses neuronal activity. Invertebrates display ataxia, paralysis, and death as the predominant signs of poisoning, with a glutamate‐gated chloride channel playing a major role. Additional target sites for the avermectins or other chloride channel‐directed compounds might include receptors gated by histamine, serotonin, or acetylcholine.The voltage‐sensitive chloride channels form another large gene family of chloride channels. Voltage‐dependent chloride channels are involved in a number of physiological processes including: maintenance of electrical excitability, chloride ion secretion and resorption, intravesicular acidification, and cell volume regulation. A subset of these channels is affected by convulsants and insecticides in mammals, although the role they play in acute lethality in insects is unclear. Given the wide range of functions that they mediate, these channels are also potential targets for insecticide development. Arch. Insect Biochem. Physiol. 54:145–156, 2003. © 2003 Wiley‐Liss, Inc.
Bt: Mode of action and use
Authors: Whalon Mark E. , Wingerd Byron A. 
Published: November 2003

AbstractThe insecticidal toxins from Bacillus thuringiensis (Bt) represent a class of biopesticides that are attractive alternatives to broad‐spectrum “hard” chemistries. The U.S. Food Quality Protection Act and the European Economic Council directives aimed at reducing the use of carbamate and organophosphate insecticides were expected to increase the use of narrowly targeted, “soft” compounds like Bt. Here we summarize the unique mode of action of Bt, which contributes to pest selectivity. We also review the patterns of Bt use in general agriculture and in specific niche markets. Despite continued predictions of dramatic growth for biopesticides due to US Food Quality Protection Act—induced cancellations of older insecticides, Bt use has remained relatively constant, even in niche markets where Bt has traditionally been relatively high. Arch. Insect Biochem. Physiol. 54:200–211, 2003. © 2003 Wiley‐Liss, Inc.
Botanical insecticides for controlling agricultural pests: Piperamides and the Colorado potato beetle Leptinotarsa decemlineata say (Coleoptera: Chrysomelidae)
Authors: Scott I.M. , Jensen H. , Scott J.G. , Isman M.B. , Arnason J.T. , Philogène B.J.R. 
Published: November 2003

AbstractThe efficacy of extracts from two Piperaceae species, Piper nigrum L. and P. tuberculatum Jacq. were evaluated using larvae and adults of the Colorado Potato Beetle Leptinotarsa decemlineata (Say). Young larvae and neonates were the most susceptible; a 24‐h LD50 of 0.064% extract of P. tuberculatum was determined for 4‐day‐old larvae, while 0.05% extract of P. nigrum reduced larval survival up to 70% within one week after treatment of potato Solanum tuberosum L. (Solanaceae) plants. When an insecticide resistant strain of L. decemlineata larvae was tested with the P. tuberculatum extract, there was less than a 2‐fold tolerance ratio compared to the 22‐fold tolerance ratio to cypermethrin, a pyrethroid. Older larvae, pre‐pupal stage and adults, were less sensitive to the P. nigrum extracts; the 24‐h LD50 was 0.5% (95% C.I. = 0.36, 0.65). However, the same concentration was equally effective under field conditions. In the greenhouse, P. nigrum at 0.5% was as effective at reducing adult L. decemlineata feeding as combinations with 2 separate botanical mixtures, garlic and lemon grass oil. Under field conditions, the residual activity of the P. nigrum extracts was less than 3 h. When adult L. decemlineata were placed on treated plants exposed to full sunlight for 0, 1.5, and 3 h, leaf damage progressively increased as the main active compound, piperine, was found to degrade by 80% after 3 h. An in vitro polysubstrate monoxygenase (PSMO) enzyme assay, using the substrate methoxyresorufin O‐demethylation (MROD), determined that the principal P. nigrum active compound, piperine, is responsible for inhibition of that specific enzyme. The results suggest that Piper extracts could be used effectively as contact botanical insect control agents to protect potato plants from developing L. decemlineata larvae at concentrations less than 0.1%. There is also potential for Piper extracts to control insecticide resistant populations in conjunction with other integrated pest management (IPM) strategies used in conventional and organic agriculture. Arch. Insect Biochem. Physiol. 54:212–225, 2003. © 2003 Wiley‐Liss, Inc.
The probability distribution of side‐chain conformations in [Leu] and [Met]enkephalin determines the potency and selectivity to μ and δ opiate receptors
Authors: Nielsen Bjørn G. , Jensen Morten Ø. , Bohr Henrik G. 
Published: November 2003

AbstractThe structure of enkephalin, a small neuropeptide with five amino acids, has been simulated on computers using molecular dynamics. Such simulations exhibit a few stable conformations, which also have been identified experimentally. The simulations provide the possibility to perform cluster analysis in the space defined by potentially pharmacophoric measures such as dihedral angles, side‐chain orientation, etc. By analyzing the statistics of the resulting clusters, the probability distribution of the side‐chain conformations may be determined. These probabilities allow us to predict the selectivity of [Leu]enkephalin and [Met]enkephalin to the known μ‐ and δ‐type opiate receptors to which they bind as agonists. Other plausible consequences of these probability distributions are discussed in relation to the way in which they may influence the dynamics of the synapse. © 2003 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 71: 577–592, 2003
Electrochemistry of Metallofullerene Films: The Major Isomer of Dy@C82
Authors: Fan Louzhen , Yang Shangfeng , Yang Shihe 
Published: November 2003

AbstractSolution‐cast films of the major isomer of Dy@C82 (Dy@C82(I)) have been studied by cyclic voltammetry (CV) in acetonitrile. The films are found to display pronounced and stable redox responses in solution. The reduction/reoxidation processes exhibit large splittings between the first two reduction and reoxidation waves. However, a pair of reversible oxidation and rereduction waves is observed after the reoxidation of a reduced film. The characteristics and the inter‐relationship of these waves are uncovered by the CV technique, scanning electron microscopy (SEM), and UV/Vis‐NIR spectra. A possible mechanism is proposed for the film electrode processes, which emphasizes the redox‐induced structural reorganization of the metallofullerene film by the incorporation and expulsion of electrolyte ions into and out of the film. The influence of the counter ion diffusivity and the ion‐pair stability on the electrochemical activity of the metallofullerene film has also been indicated.
Expanded Radialenes with Bicyclo[4.3.1]decatriene Units: New Precursors to Cyclo[n]carbons
Authors: Tobe Yoshito , Umeda Rui , Iwasa Naruhito , Sonoda Motohiro 
Published: November 2003

AbstractA new method for the formation of conjugated polyynes has been developed based on both the rearrangement of vinylidenes to alkynes and the [2+1] cheletropic fragmentation of dialkynylmethylenebicyclo[4.3.1]deca‐1,3,5‐triene derivatives. A model study of the photolysis of simple dialkynylmethylenebicyclo[4.3.1]deca‐1,3,5‐trienes resulted in cheletropic fragmentation followed by 1,2‐migration to give the corresponding linear polyynes, although undesired isomerization to methylenebicyclo[5.3.0]triene derivatives took place concurrently. Expanded [3]‐, [4]‐, [5]‐, and [6]radialene derivatives with exocyclic bicyclo[4.3.1]decatriene units were prepared by oxidative coupling of the monomeric units as precursors to the corresponding cyclo[n]carbons, monocyclic forms of carbon clusters. The spectroscopic properties of the expanded radialenes were investigated in connection with cross conjugation of the core π system and with its perturbation by the extraannular bicyclic π system. In negative‐mode laser‐desorption time‐of‐flight (LD‐TOF) mass spectra, the expanded radialenes exhibited peaks due to the corresponding cyclo[n]carbon anions (n = 18, 24, 30, and 36) formed by the stepwise loss of the aromatic indane fragments.
Photoswitching of the Magnetic Interaction between a Copper(II) Ion and a Nitroxide Radical by Using a Photochromic Spin Coupler
Authors: Takayama Kohsuke , Matsuda Kenji , Irie Masahiro 
Published: November 2003

AbstractPhotoswitching of an intramolecular spin exchange interaction between a copper(II) ion and a nitroxyl radical by using a metal complex of diarylethene has been studied by means of ESR spectroscopy. As a coordination ligand, a diarylethene with a 1,10‐phenanthroline ring and nitronyl nitroxide radical was synthesized. Mixing the diarylethene ligand with [Cu(hfac)2] (hfac=hexafluoroacetylacetone) in toluene led to a hypsochromic shift of the absorption maxima of the closed‐ring isomer due to complexation. ESR measurement in toluene at room temperature of the open‐ring isomer of the CuII complex gave a spectrum that is a superposition of the spectra from the nitroxide radical and CuII. When the sample was irradiated with 366 nm light, a new peak due to large exchange interaction appeared between those of the nitroxyl radical and CuII. This ESR measurement revealed that the magnitude of the spin exchange interaction was changed by more than 160‐fold by photoirradiation. This is the largest magnetic photoswitching phenomenon recorded in diarylethene systems.
Gas‐Phase Detection of HSOH: Synthesis by Flash Vacuum Pyrolysis of Di‐tert‐butyl Sulfoxide and Rotational‐Torsional Spectrum
Authors: Winnewisser Gisbert , Lewen Frank , Thorwirth Sven , Behnke Markus , Hahn Josef , Gauss Jürgen , Herbst Eric 
Published: November 2003

AbstractGas‐phase oxadisulfane (HSOH), the missing link between the well‐known molecules hydrogen peroxide (HOOH) and disulfane (HSSH), was synthesized by flash vacuum pyrolysis of di‐tert‐butyl sulfoxide. Using mass spectrometry, the pyrolysis conditions have been optimized towards formation of HSOH. Microwave spectroscopic investigation of the pyrolysis products allowed—assisted by high‐level quantum‐chemical calculations—the first measurement of the rotational‐torsional spectrum of HSOH. In total, we have measured approximately 600 lines of the rotational‐torsional spectrum in the frequency range from 64 GHz to 1.9 THz and assigned some 470 of these to the rotational‐torsional spectrum of HSOH in its ground torsional state. Some 120 out of the 600 lines arise from the isotopomer H34SOH. The HSOH molecule displays strong c‐type and somewhat weaker b‐type transitions, indicating a nonplanar skew chain structure, similar to the analogous molecules HOOH and HSSH. The rotational constants (MHz) of the main isotopomer (A=202 069, B=15 282, C=14 840), determined by applying a least‐squares analysis to the presently available data set, are in excellent agreement with those predicted by quantum‐chemical calculations (A=202 136, B=15 279, C=14 840). Our theoretical treatment also derived the following barrier heights against internal rotation in HSOH (when in the cis and trans configurations) to be Vcis≈2216 cm−1 and Vtrans≈1579 cm−1. The internal rotational motion results in detectable torsional splittings that are dependent on the angular momentum quantum numbers J and Ka.
Supramolecular Control of the Template‐Induced Selective Photodimerization of 4‐Methyl‐7‐O‐hexylcoumarin
Authors: Skene William G. , Couzigné Emilie , Lehn Jean‐Marie 
Published: November 2003

AbstractA symmetric ditopic molecular receptor (3), containing two identical hydrogen‐bonding recognition subunits, was designed and synthesized. These subunits are capable of binding substrates with complementary donor and acceptor sites to form a supramolecular complex through hydrogen bonding. Receptor 3 was designed to accept two guest molecules, which are held in close proximity within the supramolecular species. The substrate molecule, 4‐methyl‐7‐O‐hexylcoumarin (1 c), forms a 2:1 complex with a binding constant of 150 m−1 for the second substrate, passing first through a 1:1 complex with an affinity constant of 510 m−1. The orientation of two molecules of 1 c when bound to the template leads to the selective formation of the trans‐syn [2+2] photoproduct 2 cB upon irradiation. Other photoproducts typically produced in the absence of the template are suppressed.
A phase II study of topotecan with vincristine and doxorubicin in children with recurrent/refractory neuroblastoma
Authors: Garaventa Alberto , Luksch Roberto , Biasotti Simona , Severi Gianluca , Pizzitola Maria Rosa , Viscardi Elisabetta , Prete Arcangelo , Mastrangelo Stefano , Podda Marta , Haupt Riccardo , De Bernardi Bruno 
Published: November 2003

AbstractBACKGROUNDA Phase II trial in children with advanced neuroblastoma was carried out in five Italian institutions to evaluate the antitumor activity and tolerability of topotecan followed by vincristine and doxorubicin.METHODSChildren older than age 1 year with Stage III or Stage IV neuroblastoma, all of whom had been treated previously with chemotherapy and were diagnosed with either refractory or recurrent disease, were treated with topotecan at an intravenous dose of 1.5 mg/m2 (the dose was 0.75 mg/m2 for patients who were treated within 1 year of previous megatherapy) per day for 5 days followed by 48‐hour intravenous infusions of 2 mg/m2 vincristine and 45 mg/m2 doxorubicin. Cycles of therapy were repeated every 3 weeks.RESULTSTwenty‐five patients (2 with Stage III disease and 23 with Stage IV disease; 19 with refractory disease and 6 with recurrent disease) were treated with a total of 115 cycles. Four patients had complete responses, 12 patients had partial responses, 4 patients had minor responses or stable disease, and 5 patients had tumor progression. The overall response rate (including complete and partial responses) was 64% (95% confidence interval, 43–82%). Fifteen patients were alive at the time of the current report and were progression free at 4–16 months (median, 9 months) after the first course of this treatment. Toxicity generally was limited to the hematopoietic system. Dose‐limiting toxicity was observed in only 1 patient (Grade 4 liver toxicity). There were no deaths due to infectious or toxic causes.CONCLUSIONSThe topotecan‐vincristine‐doxorubicin combination was active and well tolerated in previously treated patients with advanced neuroblastoma. Cancer 2003. © 2003 American Cancer Society.
Sustainability hijacked by the sociological wall of self‐evidence
Authors: Cerin Pontus 
Published: November 2003

AbstractThe nowadays commonly applied structuring of sociological theories – the four‐fielder of Burrell and Morgan (1979) – in the environmental and sustainability agenda may, unfortunately, serve as a platform for the advocators of leaving business alone to realize win–win solutions by itself – that is obstructing change by encouraging business as usual. The reason for this hijacking of environmentalism is a dichotomization of regulation and radical change along an axis describing the nature of society. By instead focusing on power along the society continuum, the tool describing sociological theory enables policy thought that promotes a societal change towards increased sustainability. Copyright © 2003 John Wiley & Sons, Ltd and ERP Environment.