bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of acute and chronic administration of the selective 5‐HT2C receptor antagonist SB‐243213 on midbrain dopamine neurons in the rat: An in vivo extracellular single cell study
Authors: Blackburn Thomas P. , Minabe Yoshio , Middlemiss Derek N. , Shirayama Yukihiko , Hashimoto Kenji , Ashby Charles R. 
Published: October 2002

AbstractIn this study, we examined the effect of the acute and chronic administration of the selective 5‐HT2C receptor antagonist SB‐243213 (SB) on the activity of spontaneously active dopamine (DA) cells in the substantia nigra pars compacta (SNC) and ventral tegmental area (VTA) in anesthetized, albino, male Sprague‐Dawley rats. This was accomplished using the technique of in vivo extracellular single cell recording. The acute i.v. administration of SB‐243213 (0.025–3.2 mg/kg) did not significantly alter the basal firing rate or pattern of either spontaneously active SNC or VTA DA neurons compared to vehicle‐treated controls. The acute i.p. administration of either 1 or 10 mg/kg of SB‐243213 did not significantly alter the number of spontaneously active DA cells in the SNC or VTA compared to vehicle‐treated controls, whereas the 3 mg/kg dose only significantly decreased the number of spontaneously active VTA DA neurons. Overall, the 1 mg/kg dose of SB‐243213 did not significantly alter the firing pattern of either SNC or VTA DA neurons compared to vehicle‐treated controls. In contrast, the 3 mg/kg dose significantly altered the firing pattern of SNC DA neurons, whereas the 10 mg/kg dose altered the firing pattern of DA neurons in both the SNC and VTA. The repeated i.p. administration (21 days) of 1, 3, and 10 mg/kg of SB‐243213 or 20 mg/kg of clozapine produced a significant decrease in the number of spontaneously active DA cells in the VTA compared to vehicle‐treated controls. The decrease in the number of spontaneously active VTA DA cells was not reversed by the i.v. administration of (+)‐apomorphine (50 μg/kg). The repeated administration of either 1 or 3 mg/kg of SB‐243213 had minimal effects on the firing pattern of either SNC or VTA DA neurons. In contrast, the firing pattern of VTA DA neurons was significantly altered by 10 mg/kg dose of SB‐243213. Overall, our results indicate that antagonism of the 5‐HT2C receptor alters the activity of midbrain DA neurons in anesthetized rats and suggest that SB‐243213 has an atypical antipsychotic profile following chronic administration. Synapse 46:129–139, 2002. © 2002 Wiley‐Liss, Inc.
Brain imaging of18F‐fallypride in normal volunteers: Blood analysis, distribution, test‐retest studies, and preliminary assessment of sensitivity to aging effects on dopamine D‐2/D‐3 receptors
Authors: Mukherjee Jogeshwar , Christian Bradley T. , Dunigan Kelly A. , Shi Bingzhi , Narayanan Tanjore K. , Satter Martin , Mantil Joseph 
Published: October 2002

AbstractHuman studies of dopamine D2/D3 receptors using18F‐fallypride‐PET in normal volunteers were performed to evaluate brain distribution in striatal and extrastriatal regions, evaluate metabolites in blood plasma, establish PET imaging protocol for this new radiotracer, evaluate graphical methods of analysis to quantitate D2/D3 receptors, and assess the ability of18F‐fallypride to measure changes in D2/D3 receptors with aging as a model. Subjects (6; 21–63 years) had a PET scan on a Siemens HR+ scanner with18F‐fallypride and a T1‐weighted MRI scan on a 1.5T GE scanner for purposes of anatomical coregistration with PET. A 3‐h PET scan with18F‐fallypride (0.07 mCi/Kg) was carried out on each subject and repeated in 4–6 weeks. Arterial or arterialized venous blood was obtained in all subjects in order to evaluate blood activity levels and analyze metabolites in the plasma. Brain regions‐of‐interest were identified and drawn using PET and PET‐MR coregistered images. PET data was analyzed using graphical methods in which cerebellum was used as the reference region providing distribution volume ratios (DVR) from which binding potential (BP) was derived and used as a measure of concentration of receptors. Distribution of18F‐fallypride was consistent in all subjects studied and the rank order of receptor concentration was putamen > caudate > thalamus = pituitary > amygdala > colliculi > substantia nigra > hippocampus = temporal cortex > parietal cortex = occipital cortex = orbitofrontal cortex. For younger subjects, BP ranged from 37 for the putamen to 0.4 for orbitofrontal cortex, with a test–retest error of about 10%. Both hydrophilic and lipophilic metabolites were observed in arterial blood plasma and analyses showed approx. 30–40% of plasma radioactivity at 3 h was18F‐fallypride. With aging, all brain regions exhibited a significant decrease (>10% per decade) in binding of18F‐fallypride. PET studies with18F‐fallypride are thus suitable to study changes in D2/D3 receptors in striatal and extrastriatal brain regions. Synapse 46:170–188, 2002. © 2002 Wiley‐Liss, Inc.
Design‐to‐market integrating conceptual design and marketing
Authors: Vollerthun Andreas 
Published: October 2002

AbstractThis article presents an approach to integrate conceptual design and marketing by using a systems engineering approach. A methodology is applied that has successfully linked conceptual design with cost modeling to now also integrate marketing considerations. By combining technical product models and cost models with a market model in one integrated model, an added value is generated: Systems engineers can analyze entire business cases. The paper describes how the market model works, shows the interfaces to conceptual design and cost modeling, and discusses the integration into the overall design process. The full model is applied to the development of the European satellite navigation system “Galileo.” Development teams can easily change parameters in the design and analyze the effects of these changes on, for example, market revenues. To quantify differences among design alternatives, two approaches are considered: (a) a measure of effectiveness (market robustness) and (b) cash‐flow curves to model, simulate, and evaluate entire business cases. © 2002 Wiley Periodicals, Inc. Syst Eng 5: 315–326, 2002
Synthesis of Silylene and Silyl(silylene)metal Complexes
Authors: Ogino Hiroshi 
Published: October 2002

AbstractIn 1987, two research groups published the first‐ever reports on the synthesis of silylene complexes and presented structural evidence. Since then, a range of synthetic methods have been developed and a number of silylene complexes have been prepared. In 1988, we reported on the first base‐stabilized bis(silylene) complexes that can be regarded as being masked silyl(silylene) complexes. These complexes occupy a unique position among silylene and silyl(silylene) complexes in that they provide a convenient tool for studying the reactivity of coordinated silylenes. They are stable enough to be isolated, but the bond between the silylene silicon atom and the internal base can easily be cleaved by thermal perturbation to generate real silyl(silylene) complexes. To date, a number of base‐stabilized bis(silylene) complexes have been prepared in which the central metals range from group 5 to group 9. Only two base‐free silyl(silylene) complexes have been prepared. One is prepared by reacting a platinum complex with a stable silylene; the other is produced by the photolysis of a tungsten complex in the presence of a hydrodisilane. © 2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 2: 291–306, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10034
From “Parasitic” Association Reactions toward the Stoichiometry Controlled Gas Phase Synthesis of Nanoparticles: A Theoretically Driven Challenge for Experimentalists
Authors: Timoshkin Alexey Y. , Schaefer Henry F. 
Published: October 2002

AbstractIn the present record a model for the gas‐phase reactions during the chemical vapor deposition (CVD) processes of group 13–15 materials is presented, based on the results of extensive quantum‐chemical modeling. Thermodynamic criteria have been introduced to evaluate the importance of a range of association reactions. For the organometallic and hydride derivatives, association processes are found to be favorable both thermodynamically and kinetically. Formation of high mass association products takes place under CVD conditions, including laser‐assisted CVD. Structural and thermodynamic properties of the most important ring and cluster intermediates have been predicted. The stoichiometry‐controlled synthesis of the 13–15 ternary alloys and nanoparticles using cluster compounds as single‐source precursors is predicted to be viable. The association pathway described may be generalized to the CVD reactions of many binary materials (12–16, 13–16, 13–15, 14–15, 14–16). © 2002 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 2: 319–338, 2002: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.10037
Undergraduates' attitudes and beliefs about subject matter and pedagogy measured periodically in a reform‐based mathematics and science teacher preparation program
Authors: McGinnis J. Randy , Kramer Steve , Shama Gilli , Graeber Anna O. , Parker Carolyn A. , Watanabe Ted 
Published: October 2002

AbstractThis study describes the design and use of a valid and reliable instrument to measure teacher candidates' attitudes and beliefs about mathematics and science and the teaching of those subjects. The instrument, Attitudes and Beliefs about the Nature of and the Teaching of Mathematics and Science, was developed for the Maryland Collaborative for Teacher Preparation (MCTP), a statewide, standards‐based project in the National Science Foundation's Collaborative in Excellence in Teaching Preparation (CETP) Program. We report on two applications of the instrument: (a) a contrast between MCTP teacher candidates' and non‐MCTP teacher candidates' attitudes and beliefs about mathematics and science as they initially encountered reform‐based instruction in their undergraduate courses, and (b) a landscaping of how the MCTP teacher candidates' attitudes toward and beliefs about mathematics and science evolved over a 2.5‐year period. In support of current reform in science and mathematics teacher education, we determined that over an extended period the MCTP teacher candidates' attitudes and beliefs moved substantively and significantly in the direction intended. However, we also found that the non‐MCTP teacher candidates in the same reform‐based courses did not mirror this improvement in their attitudes and beliefs about mathematics and science or the teaching of those subjects. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 713–737, 2002
Classifying class I and class II compounds by hydrophobicity and hydrogen bonding descriptors
Authors: Ren S. 
Published: October 2002

AbstractThe successful development of quantitative structure‐activity relationships (QSARs) and the prediction of toxicity based on QSARs depend on the correct classification of the mechanism of toxic action of chemical compounds. The toxicity mechanism of a compound can be determined by a few existing methods, such as studying the chemical structure of the compound for certain substructures and assigning a mechanism accordingly. However, these methods are less reliable for compounds with complex structures and are usually complicated. A novel descriptor‐based method employing a multivariate statistical technique—discriminant analysis—was developed in this study for the classification of class I and class II compounds. The discriminating variables used in discriminant analysis were the hydrophobicity descriptor log(Kow) and the hydrogen bonding descriptors ELUMO, EHOMO, Q+, and Q−. Because only numerical values of these descriptors are required for this method, which can be calculated, no additional experimental work was required for the toxicity mechanism classification of new compounds. A nonlinear discriminant function was generated that could not be expressed explicitly. Assessing the predicting ability of the discriminant function by the cross‐validation method showed that a low total error rate, 4.2% was achieved. © 2002 Wiley Periodicals, Inc. Environ Toxicol 17: 415–423, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/tox.10074
Quests in a tetherless world
Authors: Bisdikian Chatschik , Hild Stefan , Lee Nathan , Perret Veronique , Naghshineh Mahmoud 
Published: October 2002

AbstractWireless research activities span a wide range of disciplines: communications engineering, software engineering and computer sciences covering all aspects of communication and services including client platforms and server deployment, network protocols and infrastructure, service development and deployment and so on. Our research group at the IBM T. J. Watson Research Center has initiated a number of research activities covering several aspects of the wireless research. In this paper, we highlight our work on the Bluetooth™ wireless technology and the BlueDrekar™ software stack, the WebSplitter middleware for content distribution, and we will share our vision for interconnecting trillion devices. Copyright © 2002 John Wiley & Sons, Ltd.
Internet connectivity for mobile ad hoc networks
Authors: Perkins Charles E. , Malinen Jari T. , Wakikawa Ryuji , Nilsson Anders , Tuominen Antti J. 
Published: October 2002

AbstractThe need for ad hoc networks arises when a number of mobile nodes gather in one particular location and form autonomous networks. Ad hoc networks can be adjoined to the Internet, introducing routing and addressing issues that require new features from ad hoc networking protocols. The Internet Gateway can offer global addressability and bidirectional Internet connectivity to every node in the ad hoc network. This can be done in such a way that mobile wireless nodes can migrate between wireless access points that have direct access to the wired Internet and the wireless ad hoc networks that do not have any such local access point infrastructure. Mobile IP can be employed to make such movement seamless (whenever physically possible), even though it occurs between domains with previously incompatible routing models. We believe that IPv6 and Mobile IPv6 afford important advantages for making such attachments, especially regarding router advertisement and address autoconfiguration. In this paper, we show how general ad hoc networks can be connected to the Internet by Internet Gateways, and then describe our specific experiments with Ad hoc On‐Demand Distance Vector Routing (AODV) for IPv6 (AODV6). After demonstrating the basic principles allowing access to the Internet, we then detail our further experiments using Mobile IPv6. Copyright © 2002 John Wiley & Sons, Ltd.
A survey of mobility models for ad hoc network research
Authors: Camp Tracy , Boleng Jeff , Davies Vanessa 
Published: October 2002

AbstractIn the performance evaluation of a protocol for an ad hoc network, the protocol should be tested under realistic conditions including, but not limited to, a sensible transmission range, limited buffer space for the storage of messages, representative data traffic models and realistic movements of the mobile users (i.e. a mobility model). This paper is a survey of mobility models that are used in the simulations of ad hoc networks. We describe several mobility models that represent mobile nodes whose movements are independent of each other (i.e. entity mobility models) and several mobility models that represent mobile nodes whose movements are dependent on each other (i.e. group mobility models). The goal of this paper is to present a number of mobility models in order to offer researchers more informed choices when they are deciding on a mobility model to use in their performance evaluations. Lastly, we present simulation results that illustrate the importance of choosing a mobility model in the simulation of an ad hoc network protocol. Specifically, we illustrate how the performance results of an ad hoc network protocol drastically change as a result of changing the mobility model simulated. Copyright © 2002 John Wiley & Sons, Ltd.
Hierarchical routing in ad hoc mobile networks
Authors: Belding‐Royer Elizabeth M. 
Published: October 2002

AbstractClustering is a method by which nodes are hierarchically organized on the basis of their relative proximity to one another. Routes can be recorded hierarchically, across clusters, to increase routing flexibility. Hierarchical routing greatly increases the scalability of routing in ad hoc networks by increasing the robustness of routes. This paper presents the Adaptive Routing using Clusters (ARC) protocol, a protocol that creates a cluster hierarchy composed of cluster leaders and gateway nodes to interconnect clusters. ARC introduces a new algorithm for cluster leader revocation that eliminates the ripple effect caused by leadership changes. Further, ARC utilizes a limited broadcast algorithm for reducing the impact of network floods. The performance of ARC is evaluated by comparing it both with other clustering schemes and with an on‐demand ad hoc routing protocol. It is shown that the cluster topology created by ARC is more stable than that created by other clustering algorithms and that the use of ARC can result in throughput increases of over 100%. Copyright © 2002 John Wiley & Sons, Ltd.
Adaptive security for multilevel ad hoc networks
Authors: Kong Jiejun , Luo Haiyun , Xu Kaixin , Gu Daniel Lihui , Gerla Mario , Lu Songwu 
Published: October 2002

AbstractSecure communication is critical in military environments in which the network infrastructure is vulnerable to various attacks and compromises. A conventional centralized solution breaks down when the security servers are destroyed by the enemies. In this paper we design and evaluate a security framework for multilevel ad hoc wireless networks with unmanned aerial vehicles (UAVs). In battlefields, the framework adapts to the contingent damages on the network infrastructure.Depending on the availability of the network infrastructure, our design is composed of two modes. In infrastructure mode, security services, specifically the authentication services, are implemented on UAVs that feature low overhead and flexible managements. When the UAVs fail or are destroyed, our system seamlessly switches to infrastructureless mode, a backup mechanism that maintains comparable security services among the surviving units. In the infrastructureless mode, the security services are localized to each node's vicinity to comply with the ad hoc communication mechanism in the scenario. We study the instantiation of these two modes and the transitions between them. Our implementation and simulation measurements confirm the effectiveness of our design. Copyright © 2002 John Wiley & Sons, Ltd.
Determination of the solid angle of an Si(Li) detector
Authors: Hopman Theodore L. , Campbell John L. 
Published: October 2002

AbstractRadial and longitudinal scanning of x‐ray detectors with a 55Fe source is a widely used method for determining their dimensions and position within the cryostat and thence deducing solid angle in an analytical arrangement. The scanning method is refined here to take account of various effects and issues hitherto ignored and therefore reducing its accuracy; these include finite source size, collimator ‘channelling,’ and uncertainty as to the correction for x‐ray attenuation in the intervening air. With proper attention to these effects, it is possible to determine the window–crystal distance to an accuracy of about 0.2 mm; this translates into an accuracy of about 3% for solid angle when the source–detector distance is about 25 mm. However, uncertainty remains in calibrating an analytical system, owing to lack of knowledge of the actual construction of any internal collimator. Copyright © 2002 John Wiley & Sons, Ltd.
A correction procedure for the self‐absorption artifacts in x‐ray Compton tomography
Authors: Brunetti Antonio , Golosio Bruno , Cesareo Roberto 
Published: October 2002

AbstractCompton tomography generally makes use of the same scanning techniques (rotations and translations) as transmission tomography but modifies the reconstruction software. However, it is also possible to use an x–y scanning technique, i.e. two independent sets of linear translations of the source and of the detector. The x–y technique allows one to scan only a limited zone of the sample, whereas the rotation–translations method needs to scan the whole sample. x–y scanning has a serious drawback: it is more sensitive than the translation–rotation technique to self‐absorption phenomena in the matrix. In this paper a new algorithm for x–y scanning reconstruction is described. This algorithm considers and corrects self‐absorption effects without requiring a priori knowledge about the chemical composition. Copyright © 2002 John Wiley & Sons, Ltd.
L‐subshell ionization of lutetium by 4He2+ ion bombardment
Authors: Hallak A. B. , Salah W. , Al‐Jundi J. , Jaghoub M. I. 
Published: October 2002

AbstractInner‐shell ionization of materials was studied using particle‐induced x‐ray emission (PIXE) and Rutherford backscattering spectrometry (RBS). Measurements of the ionization cross‐sections of lutetium were performed by impact of 4He2+ ions in the energy range 1.40–8.50 MeV. The experimental data were compared with the predictions of current theoretical models based on ion–atom collision resulting in inner‐shell ionization. The discrepancy between theory and experiment at energies lower than about 5 MeV could be partially understood by incorporating intra‐shell coupling that results in vacancy rearrangement among the three L‐subshells. Copyright © 2002 John Wiley & Sons, Ltd.
Cloning and analysis of CoEXG1, a secreted 1,3‐β‐glucanase of the yeast biocontrol agent Candida oleophila
Authors: Segal Efrat , Yehuda Hila , Droby Samir , Wisniewski Michael , Goldway Martin 
Published: October 2002

AbstractLytic enzymes may have a role in the biological control of fungi. The yeast biocontrol agent, Candida oleophila, is an excellent subject to research this matter. In the present study, CoEXG1, which encodes for a secreted 1,3‐β‐glucanase, is the first gene to be cloned from C. oleophila. It was isolated from a partial genomic library and analysed. Its open reading frame and putative promoter were expressed in baker's yeast, Saccharomyces cerevisiae. The reading frame, expressed under the inducible GAL1 promoter, caused an increased secretion of β‐glucanase, and the putative promoter region activated the lacZ reporter gene, to which it was fused. Sequencing analysis revealed that CoEXG1 carries the signature pattern of the 5 glycohydrolases family and has a putative secretion leader, as well as a high degree of identity to yeast 1,3‐β‐glucanases. The GenBank Accession No. of CoEXG1 is AF393806. Copyright © 2002 John Wiley & Sons, Ltd.