bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying and evaluating the space overhead for alternative C++ memory layouts
Authors: Sweeney Peter F. , Burke Michael 
Published: May 2003

AbstractThis paper develops a formalism that precisely characterizes when class tables are required for C++ memory layouts. A memory layout is a particular choice of data structures for implementing run‐time support for object‐oriented languages. We use this formalism to quantify and evaluate, on a set of benchmarks, the space overhead for a set of C++ memory layouts. In particular, this paper studies the space overhead due to three language features: virtual dispatch, virtual inheritance, and dynamic typing. To date, there has been no scientific quantification or evaluation of C++ memory layouts. Our approach can help C++ implementors. This work has already influenced the memory layout design choices in IBM's Visual Age C++ V5 compiler.Applying our approach to a set of five benchmarks, we demonstrate that the impact of object‐oriented space overhead can vary dramatically between applications (ranging from 0.42% to 99.79% for our benchmarks). In particular, applications whose object space is dominated by instances of classes that heavily use object‐oriented language features will be significantly impacted by the choice of a memory layout. Copyright © 2003 John Wiley & Sons, Ltd.
Investigating the use of analysis contracts to improve the testability of object‐oriented code
Authors: Briand L. C. , Labiche Y. , Sun H. 
Published: May 2003

AbstractA number of activities involved in testing software are known to be difficult and time consuming. Among them is the definition and coding of test oracles and the isolation of faults once failures have been detected. Through a thorough and rigorous empirical study, we investigate how the instrumentation of contracts could address both issues. Contracts are known to be a useful technique in specifying the precondition and postcondition of operations and class invariants, thus making the definition of object‐oriented analysis or design elements more precise. It is one of the reasons the Object Constraint Language (OCL) was made part of the Unified Modeling Language. Our aim in this paper is to reuse and instrument contracts to ease testing. A thorough case study is run where we define OCL contracts, instrument them using a commercial tool and assess the benefits and limitations of doing so to support the automated detection of failures and the isolation of faults. As contracts can be defined at various levels of detail, we also investigate the cost and benefit of using contracts at different levels of precision. We then draw practical conclusions regarding the applicability of the approach and its limitations. Copyright © 2003 John Wiley & Sons, Ltd.
Odyssey: a high‐performance clustered video server
Authors: Wu Min‐You , Shu Wei , Lin Chow‐Sing 
Published: May 2003

AbstractVideo servers are essential in video‐on‐demand and other multimedia applications. In this paper, we present our high‐performance clustered CBR video server, Odyssey. Odyssey is a server connecting PCs with switched Ethernet. It provides efficient support for normal play and interactive browsing functions such as fast‐forward and fast‐backward. We designed a set of algorithms for scheduling, synchronization and admission control, which results in a high utilization of resources. Odyssey is able to deliver a large number of video streams. Copyright © 2003 John Wiley & Sons, Ltd.
Alpha 4 nicotinic acetylcholine receptor subunit links cholinergic to brainstem monoaminergic neurotransmission
Authors: Cucchiaro Giovanni , Commons Kathryn G. 
Published: May 2003

AbstractAgonists of nicotinic receptors containing the α4‐subunit produce antinociception accompanied by several adverse side effects. The purpose of this study was to determine the distribution of the α4‐subunit of nicotinic acetylcholine receptors (nAChR) in brainstem monoaminergic nuclei that may contribute to these effects using dual labeling immunofluorescence methods. The α4‐subunit immunoreactivity was enriched in serotonergic (nucleus raphe magnus, pallidus, obscurus, and dorsalis) and noradrenergic (A5, locus coeruleus (LC), A7) areas associated with antinociception, where it was commonly colocalized with serotonin (5‐HT) or tyrosine hydroxylase (TH) immunoreactivity. However, it was also noted that α4 was present in all other brainstem monoaminergic nuclei examined (adrenergic C1–C3, noradrenergic A1–α4, dopamine A9 and A10, nucleus raphe medianus). To determine if α4 agonists could impact neural activity in brainstem, monoaminergic nuclei that are associated with antinociception, the expression of c‐Fos in response to the systemic administration of epibatidine (2.5, 5, or 10 μg/kg) was examined. Epibatidine produced a robust (2–5‐fold) increase in c‐Fos expression, which was not dose dependent, in all of these areas examined except the nucleus raphe magnus. These results suggest that the α4 subunit is positioned to mediate the effects of acetylcholine widely across many, if not all, monoaminergic neurons in the brainstem. These observations emphasize the potential involvement of noradrenergic, as well as serotonergic mechanisms in epibatidine's analgesic effects, and they also suggest that even selective α4 ligand may have widespread effects on brain monoamine neurotransmission. Synapse 49:195–205, 2003. © 2003 Wiley‐Liss, Inc.
Differential regulation by stimulants of neocortical expression of mrt1, arc, and homer1a mRNA in the rats treated with repeated methamphetamine
Authors: Fujiyama Ko , Kajii Yasushi , Hiraoka Shuichi , Nishikawa Toru 
Published: May 2003

AbstractThe present work was conducted to obtain clues for the possible roles of a novel stimulant‐inducible gene mrt1 (methamphetamine‐responsive transcript 1) encoding a PDZ‐PX protein in stimulant‐induced behavioral sensitization. In the young adult rats, repeated daily treatment with methamphetamine (4 mg/kg, intraperitoneally, once a day) for 5 days caused an enhanced behavioral response to methamphetamine: behavioral sensitization. The 5‐day intermittent administration of MAP upregulated the basal expression of mrt1 transcripts and eliminated the increasing effects of a challenge dose of MAP (1.6 mg/kg, i.p.) or cocaine (30 mg/kg, i.p.) on mrt1 expression on day 14 of withdrawal in the neocortex that has been considered to be composed of a neuron circuit implicated in the sensitization phenomenon. In contrast, the basal expression of other stimulant‐inducible and plasticity‐related genes arc and homer1a and the ability of MAP or cocaine challenge to augment the amounts of their transcripts were not affected by the repeated MAP regimen in the cortical area. These findings suggest the differential regulation by stimulant of neocortical mrt1, arc, and homer1a expression in the behaviorally sensitized animals and supports the view that stimulant induction of mrt1 may be involved in the early molecular signalings for stimulant sensitization. Synapse 49:143–149, 2003. © 2003 Wiley‐Liss, Inc.
[11C]‐NS 4194 versus [11C]‐DASB for PET imaging of serotonin transporters in living porcine brain
Authors: Jensen Svend B. , Smith Donald F. , Bender Dirk , Jakobsen Steen , Peters Dan , Nielsen Elsebet Ø. , Olsen Gunnar M. , Scheel‐Krüger Jørgen , Wilson Alan , Cumming Paul 
Published: May 2003

AbstractIn vitro, the novel diazabicyclononane NS 4194 has several thousand‐fold selectivity for blocking the transport into rat brain synaptosomes of [3H]‐serotonin in comparison to [3H]‐dopamine or [3H]‐noradrenaline. We have prepared [11C]‐NS 4194 in order to test its properties for PET imaging of brain serotonin transporters in comparison with the well‐documented tracer [11C]‐DASB. Both compounds had rapid clearance from blood to brain of living pigs. The apparent equilibrium distribution volumes in cerebellum were 35 ml g−1 for [11C]‐NS 4194 and 11 ml g−1 for [11C]‐DASB. Pretreatment of pigs with citalopram did not reduce the uptake of either tracer in cerebellum, validating the use of that tissue as a nonbinding reference tissue for kinetic analysis of specific binding. The binding potential (pB) calculated for [11C]‐NS 4194 using arterial input models was close to 0.5 in the telencephalon, and was 60% displaced by citalopram. However, the reference tissue method of Lammertsma was unsuited to calculate pB for this tracer, apparently due to its excessive nonspecific binding. In contrast to the relatively homogeneous binding of [11C]‐NS 4194, the pB of [11C]‐DASB ranged from 0.6 in frontal cortex to 2 in the mesencephalon when calculated by the method of Lammertsma. Parametric maps of the pB of [11C]‐DASB showed a pattern consistent with the known distribution of serotonin transporters in pig brain in vitro, and there was a uniform displacement of 80% of the specific binding after citalopram treatment in vivo. In conclusion, [11C]‐DASB is in several respects superior to [11C]‐NS 4194 for the detection of serotonin uptake sites by PET. Synapse 49:170–177, 2003. © 2003 Wiley‐Liss, Inc.
Higher in vivo muscarinic‐2 receptor distribution volumes in aging subjects with an apolipoprotein E‐ϵ4 allele
Authors: Cohen Robert M. , Podruchny Teresa A. , Bokde Arun L.W. , Carson Richard E. , Herscovitch Peter , Kiesewetter Dale O. , Eckelman William C. , Sunderland Trey 
Published: May 2003

AbstractThe apolipoprotein E‐ϵ4 allele confers an increased susceptibility to age‐related memory problems and Alzheimer's disease. Abnormalities in the cholinergic system are also likely contributors to memory deficits associated with aging and AD. To determine the effect of the APOE‐ϵ4 allele on the muscarinic component of the cholinergic system of aging subjects, 10 healthy subjects with APOE‐ϵ4 alleles (APOE‐ϵ4+) and 10 without (APOE‐ϵ4‐), ranging in age from 52 to 75 years, were tomographically scanned with the F‐18‐labeled muscarinic‐2 (M2) selective agonist, 3‐(3‐(3‐[18F]Flouropropyl)thio)‐1,2,5‐thiadiazol‐4‐yl)‐1,2,5,6‐tetrahydro‐1‐methylpyridine ([18F]FP‐TZTP). The distribution volumes (VT) of [18F]FP‐TZTP were determined by compartmental modeling of partial volume and free fraction corrected PET scans. Regional cerebral blood flow (rCBF) measurements with H215O were also performed. Global Gray VT (840 ± 155 ml plasma/ml tissue) was greater in APOE‐ϵ4+ subjects than APOE‐ϵ4‐ subjects (660 ± 113 ml plasma/ml tissue, P = 0.01), and previously studied younger subjects. There were no significant differences between the groups with respect to rCBF, but within the APOE‐ϵ4+ group there was a trend for subjects with the higher Global Gray VTs to have lower Global Gray CBFs (r = −0.65, P < 0.06). A lower concentration of acetylcholine in the synapse of APOE‐ϵ4+ older individuals is a likely explanation for the greater [18F]FP‐TZTP distribution volumes. Synapse 49:150–156, 2003. Published 2003 Wiley‐Liss, Inc.
Synaptic organization of monosynaptic connections from mesencephalic trigeminal nucleus neurons to hypoglossal motoneurons in the rat
Authors: Zhang Jingdong , Pendlebury William W. , Luo Pifu 
Published: May 2003

AbstractSynaptological characteristics of synapses between axonal boutons of the trigeminal mesencephalic nucleus (Vme) neurons and the hypoglossal nucleus (XII) motoneurons (MNs) were studied using biotinylated dextran amine (BDA) anterograde labeling combined with horseradish peroxidase (HRP) retrograde transport in the rat. BDA was initially iontophoresed into Vme unilaterally and 7 days later HRP was injected into the anterior two‐thirds of the ipsilateral tongue. After histochemical reactions, BDA anterogradely labeled boutons were seen to appose closely to somata and dendrites of HRP retrogradely labeled MNs in XII by light microscopy. A total of 212 BDA‐labeled Vme boutons were examined ultrastructurally, which had an average diameter of 1.3 ± 0.4 μm and contain small clear spherical vesicles. Eighty‐eight percent of Vme boutons (187/212) synapsed on dendrites of HRP‐labeled XII MNs. Twenty‐five Vme boutons (25/212, 12%) made synapses with somata of HRP‐labeled XII MNs. Thirty‐five percent (74/212) of BDA‐labeled Vme boutons were also contacted by unlabeled P‐type terminals. Presynaptic P‐type terminals contained spherical (47%, 35/74), pleomorphic (43%, 32/74), and flattened (10%, 7/74) synaptic vesicles. Thus, P‐type terminals (as a presynaptic element), BDA‐labeled Vme boutons, and XII MNs constitute axoaxodendritic and axoaxosomatic synaptic triads. There are four types of synaptic microcircuits in XII neuropil: synaptic convergence, synaptic divergence, presynaptic inhibition synaptic circuits, and feedforward regulation circuits. This detailed ultrastructure examination of the synaptic organization between Vme neurons and XII MNs provides insights into the synaptic mechanisms of the trigeminal proprioceptive afferents involved in the jaw–tongue reflex and coordination during oral motor behaviors. Synapse 49:157–169, 2003. © 2003 Wiley‐Liss, Inc.
Stressor controllability modulates stress‐induced serotonin but not dopamine efflux in the nucleus accumbens shell
Authors: Bland Sondra T. , Twining Carin , Watkins Linda R. , Maier Steven F. 
Published: May 2003

AbstractThe ability of an organism to control a stressor can modulate many of the consequences of stress. Previous research indicates that uncontrollable stress (inescapable shock, IS) activates serotonergic (5‐HT) neurons of the dorsal raphe nucleus (DRN) to a greater degree than controllable stress (escapable shock, ES), potentiating 5‐HT efflux in the DRN and in target regions. Previous research also indicates that IS selectively affects dopamine (DA) efflux. The present study measured 5‐HT and DA efflux in the NAc shell during IS or ES using in vivo microdialysis. Male Sprague Dawley rats with probes in the NAc shell were dialysed while subjected to 100 1.0 mA tailshocks. Rats were run in yoked pairs in wheel‐turn boxes such that one rat (ES) in the pair could terminate the shock received by both himself and his yoked (IS) partner by a behavioral response. No stress controls remained in the dialysis bowls. 5‐HT efflux selectively increased during IS, and remained increased throughout as well as after the stress session. There was no effect of stress on DA efflux. These results indicate that the NAc 5‐HT response is preferentially sensitive to stress and can be modulated by stressor controllability. Synapse 49:206–208, 2003. © 2003 Wiley‐Liss, Inc.
Cytoskeletal changes in the hippocampus following restraint stress: Role of serotonin and microtubules
Authors: Bianchi Massimiliano , Heidbreder Christian , Crespi Francesco 
Published: May 2003

AbstractThe aetiology of depression is associated with depletion in central levels of serotonin (5‐HT). Hence, a major effect of antidepressant drugs is to increase synaptic 5‐HT levels. Stressful conditions have also been shown to affect neuronal plasticity and 5‐HT neurotransmission in the hippocampus. Neuronal plasticity, which is typically referred to as a structural adaptation of neurons to functional requirements, requires more dynamic forms of microtubules (cytoskeletal component). The α‐tubulin, which is the major component of microtubules, can be postranslationally modified and both the tyrosinated (tyr‐tub) and acetylated (acet‐tub) forms are considered markers of more dynamic or more stable microtubules, respectively. The aim of the present work was to investigate the expression of tyr‐tub and acet‐tub in the hippocampus of rats submitted to either acute (6 h for 1 day) or sub‐chronic (6 h for 4 days every day) restraint stress. In addition, ex vivo hippocampal 5‐HT levels were monitored by differential pulse voltammetry to analyse the influence of both stress conditions upon 5‐HT levels. Our results showed that the expression of tyr‐tub in the hippocampus was significantly decreased to 70 ± 7% following sub‐chronic restraint stress (P < 0.01). In contrast, acute and sub‐chronic restraint stress increased the hippocampal expression of acet‐tub to 139 ± 11% and 145 ± 11% of control, respectively. Finally, 5‐HT levels were significantly increased (P < 0.05) to 142 ± 15% and 135 ± 11% following acute and sub‐chronic restraint stress, respectively. The stress‐induced cytoskeletal changes observed in the present study suggest that the microtubular network is a potential new pathway that may increase our understanding of stress‐related events. Synapse 49:188–194, 2003. © 2003 Wiley‐Liss, Inc.
Monoamine oxidase A imaging in peripheral organs in healthy human subjects
Authors: Fowler Joanna S. , Logan Jean , Wang Gene‐Jack , Franceschi Dinko , Volkow Nora D. , Telang Frank , Pappas Naomi , Ferrieri Richard , Shea Colleen , Garza Victor , Xu Youwen , King Payton , Schlyer David , Gatley S. John , Ding Yu‐Shin , Warner Donald , Netusil Noelwah , Carter Pauline , Jayne Millard , Alexoff David , Zhu Wei , Vaska Paul 
Published: May 2003

AbstractMonoamine oxidase (MAO) catalyzes the oxidative deamination of many biogenic and dietary amines. Though studies of MAO have focused mainly on its regulatory role in the brain, MAO in peripheral organs also represents a vast mechanism for detoxifying vasoactive compounds as well as for terminating the action of physiologically active amines, which can cross the blood brain barrier. Indeed, robust central and peripheral MAO activity is a major requirement in the safe use of many CNS drugs, particularly antidepressants, and thus an awareness of the MAO inhibitory potential of drugs is essential in therapeutics. In this study, we examined the feasibility of quantifying MAO A in peripheral organs in healthy human subjects using comparative positron emission tomography (PET) imaging with carbon‐11 (t1/2: 20.4 min) labeled clorgyline ([11C]clorgyline) a suicide inactivator of MAO A and its deuterium labeled counterpart ([11C]clorgyline‐D2). Heart, lungs, kidneys, thyroid, and spleen showed a robust deuterium isotope effect characteristic of MAO and the magnitude of the effect was similar to that of trancylcypromine, an irreversible MAO inhibitor used in the treatment of depression. Liver time‐activity curves were not affected by deuterium substitution precluding the estimation of liver MAO in vivo. In organs showing an isotope effect, MAO A is greatest in the lungs and kidneys followed by the thyroid and heart. This method, which has been previously applied in the human brain, opens the possibility to also directly assess the effects of different variables including smoking, dietary substances, drugs, disease, and genetics on peripheral MAO A in humans. Synapse 49:178–187, 2003. Published 2003 Wiley‐Liss, Inc.
Hierarchical mobility database overflow control
Authors: Xiao Yang 
Published: May 2003

AbstractIn a 3G cellular network, the gateway location registers (GLRs), the visitor location registers (VLRs) and the home location registers (HLRs) form a three‐level mobility database structure. An HLR database is used to record mobile users' permanent subscription information. A VLR database is used to temporarily hold the subscription information of the roaming users who visit the service area of the VLR. A GLR is deployed at the edge of a visited network handling the location management of a roaming subscriber in a visited network without involving the HLR, and holding users' temporary subscription information when the mobile user is within the service area of the GLR. When users leave the GLR/VLR service area, the corresponding records in the GLR/VLR are deleted. Owing to mobility, a GLR/VLR database may overflow at some time periods when the number of visitors significantly increases in the GLR/VLR area. If the GLR/VLR is full, the registration procedure fails and the system cannot deliver services to incoming users under the existing cellular technology. This issue is called GLR/VLR overflow.In this paper, we propose a hierarchical database overflow control mechanism in 3G cellular networks to effectively eliminate the GLR/VLR overflow problem, and incoming users can continuously use the service with insignificant extra overhead. An analytic model is proposed to investigate the performance of the hierarchical database overflow control scheme. Our study not only shows that the probability of VLR overflow is very small but also shows that among the VLR overflow cases, there is a very small probability of GLR overflow. In other words, the overhead in terms of causing both local and remote/international signaling traffic by exercising our approach is very small. Copyright © 2003 John Wiley & Sons, Ltd.
Handoff performance in wireless DS‐CDMA networks
Authors: Mišić Jelena , Mišić Vojislav B. , Tang Yat Kwan 
Published: May 2003

AbstractThis paper analyses the performance of DS‐CDMA networks in the presence of call handoffs. We show that a handoff may violate the SINR requirements for other users, and thus cause an outage in the target cell. We propose to use the probability of such events as a possible metric for quality of service in networks with multiple traffic types, and derive the corresponding QoS parameters. A two‐level admission policy is defined: in tier 1 policy, the network capacity is calculated on the basis of the bound on outage probability. However, this policy does not suffice to prevent outage events upon handoffs for various traffic types, and henceforth, we propose an extension that reserves extra bandwidth for handoff calls, thus ensuring that handoff calls will not violate the outage probability bound. The overhead imposed by the extension is negligible, as the complete two‐tier admission control algorithm is executed only when a call is admitted into the network. Once admitted, calls can freely execute handoffs using the reserved bandwidth. The modified second‐tier bandwidth reservation policy is adaptive with respect to the traffic intensity and user's mobility and we show that it can provide satisfactory call (flow) quality during its lifetime. Analytical results for the QoS have been verified by the simulations. Copyright © 2002 John Wiley & Sons, Ltd.
A batch‐update strategy for the distributed HLRs architecture in PCS networks
Authors: Hwang Hang‐Wen , Tseng Chien‐Chao , Chang Ming‐Feng 
Published: May 2003

AbstractOwing to the increasing population of mobile subscribers, the rapidly expanding signaling traffic has become a challenge to the mobility management in PCS networks. Multiple database schemes to reduce signal traffic and to solve the bottleneck problem of the singlehome location register(HLR) architecture have been proposed by many researchers. However, in most of the multiple location databases or HLR systems, extra signaling is required for the multiple database updates. We propose a batch‐update strategy, instead of the immediate update method, for the location‐tracking schemes with replication to reduce the signaling overhead. In this paper, we first introduce a distributed HLRs architecture in which each HLR is associated with a localized set of VLRs and the location registrations and queries are processed locally. Then we propose our batch‐update strategy and present two pointing schemes for inter‐HLR call deliveries. The numerical result shows that our approach can effectively decrease the signaling cost of location registration and call delivery compared with the IS‐41 standard. Copyright © 2002 John Wiley & Sons, Ltd.