bluuebunny/crossref_metadata_2025_split huggingface dataset:
Postnatal development of pre‐ and postsynaptic GABA markers at chandelier cell connections with pyramidal neurons in monkey prefrontal cortex
Authors: Cruz Dianne A. , Eggan Stephen M. , Lewis David A. 
Published: September 2003

AbstractThe protracted postnatal maturation of the primate prefrontal cortex (PFC) is associated with substantial changes in the number of excitatory synapses on pyramidal neurons, whereas the total number of inhibitory synapses appears to remain constant. In this study, we sought to determine whether the developmental changes in excitatory input to pyramidal cells are paralleled by changes in functional markers of inhibitory inputs to pyramidal neurons. The chandelier subclass of γ‐aminobutyric acid (GABA) neurons provides potent inhibitory control over pyramidal neurons by virtue of their axon terminals, which form distinct vertical structures (termed cartridges) that synapse at the axon initial segment (AIS) of pyramidal neurons. Thus, we examined the relative densities, laminar distributions, and lengths of presynaptic chandelier axon cartridges immunoreactive for the GABA membrane transporter 1 (GAT1) or the calcium‐binding protein parvalbumin (PV) and of postsynaptic pyramidal neuron AIS immunoreactive for the GABAA receptor α2 subunit (GABAA α2) in PFC area 46 of 38 rhesus monkeys (Macaca mulatta). From birth through 2 years of age, the relative densities and laminar distributions of these three markers exhibited different trajectories, suggesting developmental shifts in the weighting of at least some factors that determine inhibition at the AIS. In contrast, from 2 to 4 years of age, all three markers exhibited similar declines in density and length that paralleled the periadolescent pruning of excitatory synapses to pyramidal neurons. Across development, the predominant laminar location of PV‐labeled cartridges and GABAA α2‐immunoreactive AIS shifted from the middle to superficial layers, whereas the laminar distribution of GAT1‐positive cartridges did not change. Together, these findings suggest that the maturation of inhibitory inputs to the AIS of PFC pyramidal neurons is a complex process that may differentially affect the firing patterns of subpopulations of pyramidal neurons at specific postnatal time points. J. Comp. Neurol. 465:385–400, 2003. © 2003 Wiley‐Liss, Inc.
Perinatal and early postnatal changes in the expression of monocarboxylate transporters MCT1 and MCT2 in the rat forebrain
Authors: Baud Olivier , Fayol Laurence , Gressens Pierre , Pellerin Luc , Magistretti Pierre , Evrard Philippe , Verney Catherine 
Published: September 2003

AbstractIn addition to glucose, monocarboxylates including lactate represent a major source of energy for the brain, especially during development. We studied the immunocytochemical expression of the monocarboxylate transporters MCT1 and MCT2 in the rat brain between embryonic day (E) 16 and postnatal day (P) 14. At E16–18, MCT1‐like immunoreactivity was found throughout the cortical anlage, being particularly marked medially in the hippocampal anlage next to the ventricle. In a complementary pattern, MCT2‐like immunoreactivity was expressed along the medial and ventral border of the ventricle in the medial septum and habenula before birth. The hypothalamic area exhibited MCT2 and MCT1 positive areas from E18 on. These transient labelings revealed four main sites of monocarboxylate and/or glucose exchange: the brain parenchyma, the epithelial cells, the ependymocytes, and the glia limitans. During the first postnatal week, MCT1 immunoreactivity extended massively to the vessel walls and moderately to the developing astrocytes in the cortex. In contrast, MCT2 immunoreactivity was faint in blood vessels but massive in developing astrocytes from P3 to P7. Neither MCT2 nor MCT1 colocalized with neuronal, microglial, or oligodendrocytic markers during the first postnatal week. At P14, a part of the scattered punctate MCT2 staining could be associated with astrocytes and postsynaptic dendritic labeling. The transient pattern of expression of MCTs throughout the perinatal period suggests a potential relationship with the maturation of the blood‐brain barrier. J. Comp. Neurol. 465:445–454, 2003. © 2003 Wiley‐Liss, Inc.
Constitutive expression of p55TNFR mRNA and mitogen‐specific up‐regulation of TNFα and p75TNFR mRNA in mouse brain
Authors: Bette Michael , Kaut Oliver , Schäfer Martin K.‐H. , Weihe Eberhard 
Published: September 2003

AbstractSerum tumor necrosis factor (TNF) functions as a mediator of the immune‐to‐brain axis. Numerous TNF receptor‐mediated effects on the nervous system are described but the knowledge about the regional and cellular expression of TNF receptor p55TNFR and p75TNFR in vivo is far from being complete. It is unclear whether TNF mediates its neuroimmune effects alone or in combination with other factors, e.g., bacterial mitogens. Here, we investigated the distribution of TNFα, p55TNFR, and p75TNFR in normal mouse brain and examined the stimulus‐specific effects of lipopolysaccharide (LPS) and staphylococcal enterotoxin B (SEB) on the expression of the cerebral TNF system. Both mitogens caused enhanced TNFα serum levels and induced c‐fos mRNA in the paraventricular nucleus but exhibited different effects on the cerebral gene expression of the TNF system. LPS but not SEB rapidly induced TNFα mRNA in circumventricular organs (CVOs) followed by spreading of TNFα mRNA into brain parenchyma close to the CVOs. The p55TNFR gene was constitutively expressed in many neurons with high levels in brainstem motor nuclei and in neurons of the sensory mesencephalic trigeminal nucleus. Moderate levels of p75TNFR mRNA were seen in single cells scattered throughout the brain in a pattern resembling microglia. Neither LPS nor SEB modulated the p55TNFR gene expression in any region or cell type of the brain, and LPS but not SEB induced p75TNFR mRNA in the CVOs. Thus, enhanced TNF serum levels able to stimulate c‐fos mRNA expression in the paraventricular nucleus did not necessarily result in a modulation of the cerebral TNF system. J. Comp. Neurol. 465:417–430, 2003. © 2003 Wiley‐Liss, Inc.
Upper bound on the coarsening rate for an epitaxial growth model
Authors: Kohn Robert V. , Yan Xiaodong 
Published: September 2003

AbstractWe study a specific example of energy‐driven coarsening in two space dimensions. The energy is ∫|∇∇u|2 + (1 ‐ | ∇u|2)2; the evolution is the fourth‐order PDE representing steepest descent. This equation has been proposed as a model of epitaxial growth for systems with slope selection. Numerical simulations and heuristic arguments indicate that the standard deviation of u grows like t1/3, and the energy per unit area decays like t‐1/3. We prove a weak, one‐sided version of the latter statement: The time‐averaged energy per unit area decays no faster than t‐1/3. Our argument follows a strategy introduced by Kohn and Otto in the context of phase separation, combining (i) a dissipation relation, (ii) an isoperimetric inequality, and (iii) an ODE lemma. The interpolation inequality is new and rather subtle; our proof is by contradiction, relying on recent compactness results for the Aviles‐Giga energy. © 2003 Wiley Periodicals, Inc.
Purely nonlinear instability of standing waves with minimal energy
Authors: Comech Andrew , Pelinovsky Dmitry 
Published: September 2003

AbstractWe consider Hamiltonian systems with U(1) symmetry. We prove that in the generic situation the standing wave that has the minimal energy among all other standing waves is unstable, in spite of the absence of linear instability. Essentially, the instability is caused by higher algebraic degeneracy of the zero eigenvalue in the spectrum of the linearized system. We apply our theory to the nonlinear Schrödinger equation. © 2003 Wiley Periodicals, Inc.
Gauged harmonic maps, Born‐Infeld electromagnetism, and magnetic vortices
Authors: Lin Fanghua , Yang Yisong 
Published: September 2003

AbstractWe study maps from a 2‐surface into the standard 2‐sphere coupled with Born‐Infeld geometric electromagnetism through an Abelian gauge field. Such a formalism extends the classical harmonic map model, known as the σ‐model, governing the spin vector orientation in a ferromagnet allows us to obtain the coexistence of vortices and antivortices characterized by opposite, self‐excited, magnetic flux lines. We show that the Born‐Infeld free parameter may be used to achieve arbitrarily high local concentration of magnetic flux lines that the total minimum energy is an additive function of these quantized flux lines realized as the numbers of vortices antivortices. In the case where the underlying surface, or the domain, is compact, we obtain a necessary sufficient condition for the existence of a unique solution representing a prescribed distribution of vortices antivortices. In the case where the domain is the full plane, we prove the existence of a unique solution representing an arbitrary distribution of vortices and antivortices. Furthermore, we also consider the Einstein gravitation induced by these vortices, known as cosmic strings, establish the existence of a solution representing a prescribed distribution of cosmic strings cosmic antistrings under a necessary sufficient condition that makes the underlying surface a complete surface with respect to the induced gravitational metric. © 2003 Wiley Periodicals, Inc.
The scattering support
Authors: Kusiak Steven , Sylvester John 
Published: September 2003

AbstractWe discuss inverse problems for the Helmholtz equation at fixed energy, specifically the inverse source problem and the inverse scattering problem from a medium or an obstacle. We introduce the convex scattering support of a far field, a set which will be a subset of the convex hull of the support of any source which can produce it. We give several theorems which explain how to compute the convex scattering support and how to relate it to the actual support of a source, medium, or obstacle. © 2003 Wiley Periodicals, Inc.
One‐bit sigma‐delta quantization with exponential accuracy
Authors: Güntürk C. Si̇nan 
Published: September 2003

AbstractOne‐bit quantization is a method of representing bandlimited signals by ±1 sequences that are computed from regularly spaced samples of these signals; as the sampling density λ → ∞, convolving these one‐bit sequences with appropriately chosen filters produces increasingly close approximations of the original signals. This method is widely used for analog‐to‐digital and digital‐to‐analog conversion, because it is less expensive and simpler to implement than the more familiar critical sampling followed by fine‐resolution quantization. However, unlike fine‐resolution quantization, the accuracy of one‐bit quantization is not well‐understood. A natural error lower bound that decreases like 2−λ can easily be given using information theoretic arguments. Yet, no one‐bit quantization algorithm was known with an error decay estimate even close to exponential decay. In this paper, we construct an infinite family of one‐bit sigma‐delta quantization schemes that achieves this goal. In particular, using this family, we prove that the error signal for π‐bandlimited signals is at most O(2−.07λ). © 2003 Wiley Periodicals, Inc.
SCALEA: a performance analysis tool for parallel programs
Authors: Truong Hong‐Linh , Fahringer Thomas 
Published: September 2003

AbstractMany existing performance analysis tools lack the flexibility to control instrumentation and performance measurement for code regions and performance metrics of interest. Performance analysis is commonly restricted to single experiments.In this paper we present SCALEA, which is a performance instrumentation, measurement, analysis, and visualization tool for parallel programs that supports post‐mortem performance analysis. SCALEA currently focuses on performance analysis for OpenMP, MPI, HPF, and mixed parallel programs. It computes a variety of performance metrics based on a novel classification of overhead. SCALEA also supports multi‐experiment performance analysis that allows one to compare and to evaluate the performance outcome of several experiments. A highly flexible instrumentation and measurement system is provided which can be controlled by command‐line options and program directives. SCALEA can be interfaced by external tools through the provision of a full Fortran90 OpenMP/MPI/HPF frontend that allows one to instrument an abstract syntax tree at a very high‐level with C‐function calls and to generate source code. A graphical user interface is provided to view a large variety of performance metrics at the level of arbitrary code regions, threads, processes, and computational nodes for single‐ and multi‐experiment performance analysis. Copyright © 2003 John Wiley & Sons, Ltd.
Fairness in systems based on multiparty interactions
Authors: Ruiz David , Corchuelo Rafael , Toro Miguel 
Published: September 2003

AbstractIn the context of the Multiparty Interaction Model, fairness is used to insure that an interaction that is enabled sufficiently often in a concurrent program will eventually be selected for execution. Unfortunately, this notion does not take conspiracies into account, i.e. situations in which an interaction never becomes enabled because of an unfortunate interleaving of independent actions; furthermore, eventual execution is usually too weak for practical purposes since this concept can only be used in the context of infinite executions. In this article, we present a new fairness notion, k‐conspiracy‐free fairness, that improves on others because it takes finite executions into account, alleviates conspiracies that are not inherent to a program, and k may be set a priori to control its goodness to address the above‐mentioned problems. Copyright © 2003 John Wiley & Sons, Ltd.
Dynamic query scheduling in parallel data warehouses
Authors: Märtens Holger , Rahm Erhard , Stöhr Thomas 
Published: September 2003

AbstractParallel processing is a key to high performance in very large data warehouse applications that execute complex analytical queries on huge amounts of data. Although parallel database systems (PDBSs) have been studied extensively in the past decades, the specifics of load balancing in parallel data warehouses have not been addressed in detail.In this study, we investigate how the load balancing potential of a Shared Disk (SD) architecture can be utilized for data warehouse applications. We propose an integrated scheduling strategy that simultaneously considers both processors and disks, regarding not only the total workload on each resource but also the distribution of load over time. We evaluate the performance of the new method in a comprehensive simulation study and compare it to several other approaches. The analysis incorporates skew aspects and considers typical data warehouse features such as star schemas with large fact tables and bitmap indices. Copyright © 2003 John Wiley & Sons, Ltd.
On the performance of TCP over a TDD‐TD/CDMA architecture
Authors: Casoni Maurizio 
Published: September 2003

AbstractThis paper determines the performance of TCP when it is employed over a TDD‐TD/CDMA architecture which supports different classes of subscribers and adopts an interference‐driven admission control policy. The blocking and the outage probability of the system users are evaluated under various traffic conditions as well as the TCP throughput that data users experience. Call blocking and TCP throughput are determined by means of a semi‐analytical approach. This work shows that when TCP is taken into account, many options come out for the system design in order to optimize radio resources. Resource assignment in the TDD‐TD/CDMA system can then be done as a function of the actual radio link quality with the goal both to serve as many users as possible and to keep the TCP throughput as high as possible. Copyright © 2003 John Wiley & Sons, Ltd.
Accurate and time efficient estimation of the probability of error in bursty channels
Authors: Berber M. Stevan 
Published: September 2003

AbstractA method and a technique for the probability of error estimation in digital channels with memory are developed and demonstrated. The expressions for the mean and variance of a random variable, representing a block of bits transmission in a bursty channel (channel with memory), are derived. The influence of the memory is expressed by a parameter called the memory factor. It is shown that the traditional Monte Carlo method can be applied for the probability of error estimation. In order to control the accuracy and increase the time efficiency of estimation this method is modified and a new method, called the modified Monte Carlo method, is proposed. Based on this modified method a technique of estimation with controlled accuracy is developed and demonstrated using data obtained by simulation. According to this technique the sample size is adjusted in the course of estimating procedure to give an accurate estimate of the probability of error for a minimum required time of estimation. Copyright © 2003 John Wiley & Sons, Ltd.
Implicit bias in impression formation: associations influence the construal of individuating information
Authors: Gawronski Bertram , Geschke Daniel , Banse Rainer 
Published: September 2003

AbstractThe present research investigated the influence of group‐related evaluative associations on the process of impression formation. In particular, we expected the impact of a target's category membership on the construal of ambiguous behaviour to be moderated by perceivers' evaluative associations related to the target category. Associative strength was further expected to have an indirect effect on dispositional inference, mediated by its impact on behaviour identification. Results support both of these assumptions. Moreover, the influence of evaluative associations on impression formation was not moderated by perceivers' motivation to control prejudiced reactions. Rather, motivation to control moderated only the relation between evaluative associations and the explicit endorsement of prejudiced beliefs about the target group in general, such that explicit prejudice endorsement was correlated with evaluative associations only for perceivers low, but not for those high in motivation to control. Implications for prejudice control are discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Attitude‐behaviour consistency: the role of group norms, attitude accessibility, and mode of behavioural decision‐making
Authors: Smith Joanne R. , Terry Deborah J. 
Published: September 2003

AbstractThe interplay between two perspectives that have recently been applied in the attitude area—the social identity approach to attitude‐behaviour relations (Terry & Hogg, 1996) and the MODE model (Fazio, 1990a)—was examined in the present research. Two experimental studies were conducted to examine the role of group norms, group identification, attitude accessibility, and mode of behavioural decision‐making in the attitude‐behaviour relationship. In Study 1 (N = 211), the effects of norms and identification on attitude‐behaviour consistency as a function of attitude accessibility and mood were investigated. Study 2 (N = 354) replicated and extended the first experiment by using time pressure to manipulate mode of behavioural decision‐making. As expected, the effects of norm congruency varied as a function of identification and mode of behavioural decision‐making. Under conditions assumed to promote deliberative processing (neutral mood/low time pressure), high identifiers behaved in a manner consistent with the norm. No effects emerged under positive mood and high time pressure conditions. In Study 2, there was evidence that exposure to an attitude‐incongruent norm resulted in attitude change only under low accessibility conditions. The results of these studies highlight the powerful role of group norms in directing individual behaviour and suggest limited support for the MODE model in this context. Copyright © 2003 John Wiley & Sons, Ltd.
Self, in‐group, and out‐group evaluation: bond or breach?
Authors: De Vries Reinout E. 
Published: September 2003

AbstractA number of studies have looked at causes of in‐group bias, but few studies have actually investigated whether the two components of in‐group bias, i.e. in‐group and out‐group evaluation, are related to each other and whether they have similar or different predictors. In the Fiji Islands, self‐, in‐group, and out‐group evaluations were obtained using within‐subject correlations from a sample of 336 indigenous and Indian Fijians. Self‐evaluation was positively related to in‐group evaluation, and both were positively related to out‐group evaluation, supporting a spillover model. After controlling for background variables and the other evaluation variables, regression analyses showed that in‐group identification was positively related to in‐group evaluation, and social distance and political ethnocentrism were negatively related to out‐group evaluation. Additionally, ethnicity interacted with collective self‐esteem in determining both in‐group favouritism and out‐group derogation. Copyright © 2003 John Wiley & Sons, Ltd.
Is politician A or politician B more persuasive? recipients' source preference and the direction of biased message processing
Authors: Ziegler René , Diehl Michael 
Published: September 2003

AbstractParticipants' preference for one of two politicians running for the post of Chancellor in Germany was measured. Under conditions conducive to effortful processing, participants were then presented with a persuasive message ascribed to one of these two sources. The message was either unambiguous strong, unambiguous weak, or ambiguous. Different from previous research on the role of message ambiguity for attitude change, the ambiguous message consisted of arguments rated as moderately convincing in a pretest rather than of a mixture of strong and weak arguments. The results were in line with predictions derived from the heuristic‐systematic model (HSM). Indicating unbiased systematic processing, an unambiguous strong message led to more agreement than an unambiguous weak message. In the case of an ambiguous message, in line with the HSM's bias hypothesis, more agreement was found among participants preferring the source politician as compared to participants preferring the other politician. Copyright © 2003 John Wiley & Sons, Ltd.
Not being what you claim to be: impostors as sources of group threat
Authors: Hornsey Matthew J. , Jetten Jolanda 
Published: September 2003

AbstractWe examine the notion of impostors within groups, defined in this paper as people who make public claims to an identity while disguising their failure to fulfil key criteria for group membership. In Experiment 1, vegetarians showed heightened levels of negative affect toward vegetarians who ate meat occasionally compared to an authentic vegetarian. In contrast, non‐vegetarians saw the impostor to be marginally more likeable than the authentic vegetarian. In Experiments 2 and 3, participants evaluated only a vegetarian who ate meat. Evaluations of the target were influenced by group attachment, such that participants who identified strongly as vegetarians downgraded the target more strongly and experienced more negative affect than did moderate identifiers and non‐vegetarians. Participants were also sensitive to the size of the gulf between the target's claims for identity and their behaviour. Thus, targets who made public claims to being a vegetarian but ate meat were evaluated more negatively than were people who kept their claims for identity private (Experiment 2). Similarly, targets who tried to keep their deviant behaviour secret were evaluated more negatively than were people who openly admitted their deviant behaviour (Experiment 3). The reasons why impostors might threaten the integrity of group identities are discussed. Copyright © 2003 John Wiley & Sons, Ltd.