bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nerve growth factor‐mediated collateral sprouting of central sensory axons into deafferentated regions of the dorsal horn is enhanced in the absence of the p75 neurotrophin receptor
Authors: Hannila Sari S. , Kawaja Michael D. 
Published: April 2005

AbstractThis study examined the growth capacity of nerve growth factor (NGF)‐responsive dorsal root ganglion (DRG) central processes using mice of the following genotypes: wildtype, p75 neurotrophin receptor (p75NTR) exon III null mutant, NGF transgenic, and NGF transgenic with p75NTR exon III null mutation (NGF/p75‐/‐). In wildtype and p75NTR exon III null mutant mice calcitonin gene‐related peptide (CGRP) immunoreactivity in the dorsal horn is dramatically reduced at both 3 and 28 days after rhizotomy. NGF transgenic and NGF/p75‐/‐ mice also display reduced CGRP immunoreactivity 3 days after rhizotomy, but by postsurgical day 28 significant increases in the density of CGRP‐positive axons are observed in the injured dorsal horns of these mice. Interestingly, NGF/p75‐/‐ mice displayed significantly more new axonal growth when compared to NGF transgenic mice expressing full‐length p75NTR. Immunohistochemical and ultrastructural analyses revealed that this axonal growth is not the result of regeneration but rather injury‐induced sprouting by intact DRG central processes into the lesion site. This collateral growth is restricted to deafferentated areas of the dorsal horn, and we therefore propose that this is an example of compensatory sprouting by NGF‐sensitive axons in the spinal cord, a response that is enhanced in the absence of NGF binding to p75NTR. J. Comp. Neurol. 486:331–343, 2005. © 2005 Wiley‐Liss, Inc.
Crystal Structure and Magnetism of the Double Perovskite Sr3Fe2MoO9:A Neutron Diffraction Study
Authors: Viola María C. , Alonso José A. , Pedregosa José C. , Carbonio Raul E. 
Published: April 2005

AbstractThe Sr3Fe2MoO9 double perovskite has been prepared in polycrystalline form by heat treatment, in air, from previously decomposed citrate precursors. This material has been studied by X‐ray (XRD), neutron powder diffraction (NPD) and magnetic measurements. At room temperature, the crystal structure is tetragonal, space group I4/m, with a = b = 5.5608(2) Å, c = 7.8471(4) Å. It is convenient to write the crystallographic formula as Sr2Fe(Fe1/3Mo2/3)O6, according to the usual nomenclature for double perovskites A2B'B''O6. The structure contains alternating FeO6 and (Fe,Mo)O6 octahedra, tilted by 3.9° in the basal ab plane. Magnetic measurements indicate a weak ferromagnetic behavior below TC = 280 K. Ideally, the Sr3Fe2MoO9 double perovskite only contains Fe3+ and Mo6+ cations, in such a way that superexchange interactions between neighboring Fe3+ spins are the only nominal mechanism accounting for the magnetism of this material. Our main finding is that this intrinsically “disordered” sample, containing a random distribution of Fe and Mo at the B'' positions, exhibits a strong magnetic scattering on the low‐angle Bragg positions, originating from naturally occurring groups of Fe3+ cations in which strong antiferromagnetic (AFM) Fe–O–Fe superexchange interactions are promoted, similar to those existing in the LaFeO3 perovskite. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Cobalt(II) Complexes with Substituted Salen‐Type Ligands and Their Dioxygen Affinity in N,N‐Dimethylformamide at Various Temperatures
Authors: Huber Andreas , Müller Lutz , Elias Horst , Klement Robert , Valko Marian 
Published: April 2005

AbstractSeveral unsymmetrically substituted salen‐type cobalt(II) Schiff‐base complexes CoL [H2L = 1,6‐bis(2‐hydroxyphenyl)‐3,3‐dimethyl‐2,5‐diaza‐1,5‐hexadiene (1); 1,6‐bis(2‐hydroxyphenyl)‐3,3‐dimethyl‐2,5‐diaza‐1,5‐heptadiene (2); 1‐(3‐tert‐butyl‐2‐hydroxy‐5‐methylphenyl)‐6‐(2‐hydroxyphen‐yl)‐3,3‐dimethyl‐2,5‐diaza‐1,5‐heptadiene (3); 1‐(2‐hydroxyphenyl)‐6‐methyl‐2,5‐diaza‐1,5‐nonadien‐8‐one (4); 1‐(3‐tert‐butyl‐2‐hydroxy‐5‐methylphenyl)‐6‐methyl‐2,5‐di‐aza‐1,5‐nonadien‐8‐one (5); 1‐(2‐hydroxyphenyl)‐3,3,6‐trimethyl‐2,5‐diaza‐1,5‐nonadien‐8‐one (6); 1‐(3‐tert‐butyl‐2‐hydroxy‐5‐methylphenyl)‐3,3,6‐trimethyl‐2,5‐diaza‐1,5‐nonadien‐8‐one (7)] were prepared and characterized by their UV/Vis absorption spectra, magnetic moments, and oxidation potentials. Except for complex 4 (irreversible oxidation with t½ ≈ 3 h), complexes 1–3 and 5–7 are remarkably resistant against irreversible auto‐oxidation in air‐saturated N,N‐dimethylformamide (DMF) at ambient temperature. To characterize the Lewis acidity of the cobalt center in 1–7, the equilibrium constant Kpy was determined for monoadduct formation with pyridine (CoL + pyCoL·py). An O2‐sensitive optode was used to determine the Henry constant, KH, for the system O2/DMF in the temperature range 298–228 K. The formation of 1:1 adducts of complexes 1–7 with O2 in DMF, as characterized by the equilibrium constant K, was followed spectrophotometrically in the temperature range 298–228 K. The parameters ΔHo, ΔSo, and K are reported. At 298 K, K ranges from 21.9 M–1 (5) to 155 M–1 (7). The overall spectroscopic information, including EPR spectra obtained with frozen solutions of 3 and 7 in O2‐saturated DMF, confirm that the 1:1 adducts CoL·O2 are cobalt(III) superoxo compounds. The symmetrically substituted salen complex8 [H2L = 1,6‐bis(3‐tert‐butyl‐2‐hydroxy‐5‐methylphenyl)‐3,3,4,4‐tetramethyl‐2,5‐diaza‐1,5‐hexadiene in 8] is shown to catalyze the oxidation of triphenylphosphane and 2,6‐di‐tert‐butylphenol by O2 in DMF at ambient temperature. The correlation of the data obtained for K, Kpy, and the oxidation potential E½ is discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Crystallographic Studies of a Molybdenum‐Rich Diarsenotungstate and Reaction of FeIII with Its Isomerically Pureα1‐ and α2‐Monolacunary Derivatives
Authors: Mbomekalle Israel M. , Wei Lu Yu , Keita Bineta , Nadjo Louis , Neiwert Wade A. , Hardcastle Kenneth I. , Hill Craig L. , Anderson Travis M. 
Published: April 2005

AbstractAn isomerically pure form of the molybdenum‐richpolytungstate, [α1‐As2Mo5W12O61]10–, was prepared by adding 5 equivalents of MoVI to [α‐H2As2W12O48]12–, in thepresence of Li+. The α2‐isomer, [α2‐As2Mo5W12O61]10–, was prepared by mild alkaline (KHCO3) degradation of[α‐As2Mo6W12O62]6–. Both [α1‐As2Mo5W12O61]10– and [α2‐As2Mo5W12O61]10– react with FeIII in aqueous solution to give [α1‐As2(FeOH2)Mo5W12O61]7– (1) and [α2‐As2(FeOH2)Mo5W12O61]7– (2), respectively. The parent complex, [α‐As2Mo6W12O62]6–, was characterized by X‐ray crystallography as a mixed potassium‐sodium salt [a = 12.8412(17) Å, b = 14.8145(19) Å, c = 19.913(3) Å, α = 70.058°, β = 81.055(5)°, γ = 64,495°, triclinic, P, R1 = 4.99 % based on 9709 reflections]. All of the complexes were characterized by infrared spectroscopy, cyclic voltammetry, and elemental analyses. 183W NMR studies confirm that 1 and 2 are isomerically pure compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Amplitude modulated multipulse PPM for bandwidth‐limited optical systems
Authors: Haddad Bassel , Bross Shraga I. 
Published: April 2005

AbstractOptical direct‐detection systems have been considered before for high‐speed intersatellite links. In this paper, we consider a three‐level amplitude modulated multipulse pulse‐position modulation (PPM) for use in bandwidth limited direct detection optical systems. Specifically, we investigate the capacity, cutoff rate and error probability of this modulation scheme. This facilitates the evaluation of the bandwidth efficiency of the proposed modulation as compared to regular multipulse PPM, which delivers the same throughput and detection quality under the same average‐power constraint. Copyright © 2005 AEIT.
Differences in nuclear positioning of 1q12 pericentric heterochromatin in normal and tumor B lymphocytes with 1q rearrangements
Authors: Barki‐Celli Leila , Lefebvre Christine , Le Baccon Patricia , Nadeau Gwenael , Bonnefoix Thierry , Usson Yves , Vourc'h Claire , Khochbin Saadi , Leroux Dominique , Callanan Mary 
Published: April 2005

AbstractThe frequent rearrangement of chromosome band 1q12 constitutive heterochromatin in hematologic malignancies suggests that this rearrangement plays an important pathogenetic role in these diseases. The oncogenic mechanisms linked to 1q12 heterochromatin are unknown. Constitutive heterochromatin can epigenetically regulate gene function through the formation of transcriptional‐silencing compartments. Thus, as a first step toward understanding whether 1q12 rearrangements might compromise such activity in tumor cells, we investigated the 3‐D organization of the 1q12 heterochromatin domain (1q12HcD) in normal and tumor B lymphocytes. Strikingly, in normal B cells, we showed that the 1q12HcD dynamically organizes to the nuclear periphery in response to B‐cell receptor engagement. Specifically, we observed an almost twofold increase in 1q12Hc domains at the extreme nuclear periphery in activated versus resting B lymphocytes. Remarkably, 1q12Hc organization was noticeably altered in tumor cells that showed structural alterations of 1q12; the 1q12Hc domains were significantly displaced from the extreme nuclear periphery compared to normal activated B lymphocytes (P > 0.0001), although overall peripheral localization was maintained. In a case in which there was a translocation of IGL enhancer to 1q, the altered nuclear positioning of the 1q12HcD was even more pronounced (5% of the 1q12Hc domains at the nuclear periphery compared to 20% in other lymphoma lines), and we were able to mimic this effect in two additional B‐cell tumor lines by treatment with trichostatin A, a histone deacetylase (HDAC) inhibitor. Taken together, these results point to the 1q12HcD having a specific, nonrandom, and regulated peripheral organization in B lymphocytes. This organization is significantly disrupted in lymphoma cells harboring 1q rearrangements. © 2005 Wiley‐Liss, Inc.
Multiple roles for MMPs and TIMPs in cerebral ischemia
Authors: Cunningham Lee Anna , Wetzel Monica , Rosenberg Gary A. 
Published: April 2005

AbstractMatrix metalloproteinases (MMPs) are matrix‐degrading enzymes involved in diverse homeostatic and pathological processes. Several MMPs are expressed within the CNS and serve important normal and pathological functions during development and adulthood. An early and major pathological effect of MMP activity after cerebral ischemia is opening of the blood‐brain barrier (BBB). More recent work demonstrates emerging roles for MMPs and their natural inhibitors, tissue inhibitors of metalloproteinases (TIMPs), in the regulation of neuronal cell death. In addition, MMPs and TIMPs are likely to play important roles during the repair phases of cerebral ischemia, particularly during angiogenesis and reestablishment of cerebral blood flow. This review attempts to elucidate how MMPs and TIMPs may provide detrimental or beneficial actions during the injury and repair processes after cerebral ischemia. These processes will have important implications for therapies using MMP inhibitors in stroke. © 2005 Wiley‐Liss, Inc.
Astrocyte activation and reactive gliosis
Authors: Pekny Milos , Nilsson Michael 
Published: April 2005

AbstractAstrocytes become activated (reactive) in response to many CNS pathologies, such as stroke, trauma, growth of a tumor, or neurodegenerative disease. The process of astrocyte activation remains rather enigmatic and results in so‐called “reactive gliosis,” a reaction with specific structural and functional characteristics. In stroke or in CNS trauma, the lesion itself, the ischemic environment, disrupted blood‐brain barrier, the inflammatory response, as well as in metabolic, excitotoxic, and in some cases oxidative crises—all affect the extent and quality of reactive gliosis. The fact that astrocytes function as a syncytium of interconnected cells both in health and in disease, rather than as individual cells, adds yet another dimension to this picture. This review focuses on several aspects of astrocyte activation and reactive gliosis and discusses its possible roles in the CNS trauma and ischemia. Particular emphasis is placed on the lessons learnt from mouse genetic models in which the absence of intermediate filament proteins in astrocytes leads to attenuation of reactive gliosis with distinct pathophysiological and clinical consequences. © 2005 Wiley‐Liss, Inc.
Microglia as potential contributors to motor neuron injury in amyotrophic lateral sclerosis
Authors: Sargsyan Siranush A. , Monk Peter N. , Shaw Pamela J. 
Published: April 2005

AbstractThe central nervous system (CNS) is equipped with a variety of cell types, all of which are assigned particular roles during the development, maintenance, function and repair of neural tissue. One glial cell type, microglia, deserves particular attention, as its role in the healthy or injured CNS is incompletely understood. Evidence exists for both regenerative and degenerative functions of these glial cells during neuronal injury. This review integrates the current knowledge of the role of microglia in an adult‐onset neurodegenerative disease, amyotrophic lateral sclerosis (ALS), and pays particular attention to the possible mechanisms of initiation and propagation of neuronal damage during disease onset and progression. Microglial cell properties, behavior and detected inflammatory reactions during the course of the disease are described. The neuroinflammatory changes that occur in a mouse model of ALS are summarized. The understanding of microglial function in the healthy and injured CNS could offer better diagnostic as well as therapeutic approaches for prevention, retardation, or repair of neural tissue degeneration. © 2005 Wiley‐Liss, Inc.
Cross‐cultural effect on the brain revisited: Universal structures plus writing system variation
Authors: Bolger Donald J. , Perfetti Charles A. , Schneider Walter 
Published: April 2005

AbstractRecognizing printed words requires the mapping of graphic forms, which vary with writing systems, to linguistic forms, which vary with languages. Using a newly developed meta‐analytic approach, aggregated Gaussian‐estimated sources (AGES; Chein et al. [2002]: Psychol Behav 77:635–639), we examined the neuroimaging results for word reading within and across writing systems and languages. To find commonalities, we compiled 25 studies in English and other Western European languages that use an alphabetic writing system, 9 studies of native Chinese reading, 5 studies of Japanese Kana (syllabic) reading, and 4 studies of Kanji (morpho‐syllabic) reading. Using the AGES approach, we created meta‐images within each writing system, isolated reliable foci of activation, and compared findings across writing systems and languages. The results suggest that these writing systems utilize a common network of regions in word processing. Writing systems engage largely the same systems in terms of gross cortical regions, but localization within those regions suggests differences across writing systems. In particular, the region known as the visual word form area (VWFA) shows strikingly consistent localization across tasks and across writing systems. This region in the left mid‐fusiform gyrus is critical to word recognition across writing systems and languages. Hum Brain Mapp 25:92–104, 2005. © 2005 Wiley‐Liss, Inc.
Involvement of the inferior frontal junction in cognitive control: Meta‐analyses of switching and Stroop studies
Authors: Derrfuss Jan , Brass Marcel , Neumann Jane , von Cramon D. Yves 
Published: April 2005

AbstractThere is growing evidence that a specific region in the posterior frontolateral cortex is involved intimately in cognitive control processes. This region, located in the vicinity of the junction of the inferior frontal sulcus and the inferior precentral sulcus, was termed the inferior frontal junction (IFJ). The IFJ was shown to be involved in the updating of task representations and to be activated commonly in a within‐subject investigation of a task‐switching paradigm, the Stroop task, and a verbal n‐back task. Here, we investigate the involvement of the IFJ in cognitive control by employing a meta‐analytic approach. Two quantitative meta‐analyses of functional magnetic resonance imaging (fMRI) studies were conducted. One meta‐analysis included frontal activations from task‐switching, set‐shifting, and stimulus–response (S–R) reversal studies, the other included frontal activations from color–word Stroop studies. Results showed highly significant clustering of activations in the IFJ in both analyses. These results provide strong evidence for the consistent involvement of the IFJ in both switching and Stroop paradigms. Furthermore, they support our concept of areal specialization in the frontolateral cortex, which posits that it is not only the middorsolateral part that plays an important role in cognitive control, but also the IFJ. Finally, our results demonstrate how quantitative meta‐analyses can be used to test hypotheses about the involvement of specific brain regions in cognitive control. Hum Brain Mapp 25:22–34, 2005. © 2005 Wiley‐Liss, Inc.
Meta‐analyses of object naming: Effect of baseline
Authors: Price Cathy J. , Devlin Joseph T. , Moore Caroline J. , Morton Christopher , Laird Angela R. 
Published: April 2005

AbstractThe neural systems sustaining object naming were examined using the activation likelihood estimation (ALE) meta‐analysis approach on the results of 16 previously published studies. The activation task in each study required subjects to name pictures of objects or animals, but the baseline tasks varied. Separate meta‐analyses were carried out on studies that used: (1) high‐level baselines to control for speech processing and visual input; and (2) low‐level baselines that did not control for speech or complex visual processing. The results of the two meta‐analyses were then compared directly, revealing a double dissociation in the activation pattern for studies using high and low baselines. To interpret the differential activations, we report two new functional imaging experiments. The aim of the first was to characterize activation differences associated with visual stimuli that are typically used in baseline conditions (complex visual features, simple structures, or fixation). The aim of the second was to classify object‐naming regions in terms of whether they were engaged preferentially by semantic or phonological processes. The results reveal a remarkably precise correspondence between the areas identified by the meta‐analyses as affected differentially by baseline and the areas that are affected differentially by non‐object structure, semantics or phonology. As expected, high‐level baselines reduced object‐naming activation in areas associated with the processing of complex visual features and speech production. In addition, high‐level baselines increased sensitivity to activation in areas associated with semantic processing, visual‐speech integration and response selection. For example, activation in the anterior temporal areas that neuropsychological studies have associated with semantic processing was more strongly activated in the context of high‐level baselines. These results therefore have implications for understanding the convergence of functional imaging and neuropsychological findings. Hum Brain Mapp 25:70–82, 2005. © 2005 Wiley‐Liss, Inc.
ALE meta‐analysis: Controlling the false discovery rate and performing statistical contrasts
Authors: Laird Angela R. , Fox P. Mickle , Price Cathy J. , Glahn David C. , Uecker Angela M. , Lancaster Jack L. , Turkeltaub Peter E. , Kochunov Peter , Fox Peter T. 
Published: April 2005

AbstractActivation likelihood estimation (ALE) has greatly advanced voxel‐based meta‐analysis research in the field of functional neuroimaging. We present two improvements to the ALE method. First, we evaluate the feasibility of two techniques for correcting for multiple comparisons: the single threshold test and a procedure that controls the false discovery rate (FDR). To test these techniques, foci from four different topics within the literature were analyzed: overt speech in stuttering subjects, the color‐word Stroop task, picture‐naming tasks, and painful stimulation. In addition, the performance of each thresholding method was tested on randomly generated foci. We found that the FDR method more effectively controls the rate of false positives in meta‐analyses of small or large numbers of foci. Second, we propose a technique for making statistical comparisons of ALE meta‐analyses and investigate its efficacy on different groups of foci divided by task or response type and random groups of similarly obtained foci. We then give an example of how comparisons of this sort may lead to advanced designs in future meta‐analytic research. Hum Brain Mapp 25:155–164, 2005. © 2005 Wiley‐Liss, Inc.
Cerebellum and auditory function: An ALE meta‐analysis of functional neuroimaging studies
Authors: Petacchi Augusto , Laird Angela R. , Fox Peter T. , Bower James M. 
Published: April 2005

AbstractOver the past two decades neuroimaging data have accumulated showing that the cerebellum, traditionally viewed only as a motor structure, is also active in a wide variety of sensory and cognitive tasks. We have proposed that instead of explicit involvement in any particular motor, sensory, or cognitive task, the cerebellum performs a much more fundamental computation involving the active acquisition of sensory data. We carried out an activation likelihood estimate (ALE) meta‐analysis to determine whether neuroimaging results obtained during a wide range of auditory tasks support this proposal. Specifically, we analyzed the coordinates of 231 activation foci obtained in 15 different auditory studies selected through an extensive search of the positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) literature. The studies selected represent a wide variety of purely auditory tasks using highly controlled synthesized acoustic stimuli. The results clearly revealed that in addition to temporal auditory areas of cerebral cortex, specific regions in the cerebellum are activated consistently across studies regardless of the particular auditory task involved. In particular, one area in left lateral crus I area showed the greatest volume and ALE peak value among the extratemporal regions. A subanalysis was carried out that ruled out the specific association of this cerebellar cluster with attentional demand. The results are consistent with the hypothesis that the cerebellum may play a role in purely sensory auditory processing, and are discussed in light of the broader idea of the cerebellum subserving a fundamental sensory function. Hum Brain Mapp 25:118–128, 2005. © 2005 Wiley‐Liss, Inc.