bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of a Tetranuclear High–Spin Iron(II,III,II,III) Mixed Valence Complex
Authors: Sugimoto Hideki , Hayashi Yoshihito , Koshi Chikako , Fujinami Shuhei , Suzuki Masatatsu , Maeda Yonezou , Uehara Akira
Published: March 2006

A class II mixed valent Fe4(II,III,II,III) complex [Fe4(Me4-tpdp)2(μ-F)2(OH)2(H2O)2](BF4)4 was synthesized, where HMe4-tpdp is N,N,N′,N′-tetrakis[2-(6-methylpyridyl)methyl]-1,3-diamino-2-propanol. The crystal structure shows that the complex cation consists of two alkoxo-bridged dinuclear units which are connected by two fluoro bridges to form a bilayered structure (a box structure).
Oxidative Generation of 2-(Trifluoromethyl)- and 2-(Chlorodifluoromethyl)allylic Cations and Its Synthetic Application
Authors: Fuchigami Toshio , Yamamoto Kayoko
Published: March 2006

Oxidative generation of allylic cations having strong electron-withdrawing CF3 and CF2Cl groups from 2-(trifluoromethyl)- and 2-(chlorodifluoromethyl)allylsilanes was successfully carried out for the first time. The generated cation was trapped with nucleophiles such as arenes and acetonitrile.
Preparation of Micro-Crystalline ZrO2 with Monoclinic Structure and Its Strong Acid and Base Sites
Authors: Nakabayashi Hirotoshi
Published: March 2006

The micro-crystalline ZrO2 with the monoclinic structure was prepared by the calcination at low temperature of the Zr-hydroxide obtained by the hydrolysis of Zr-alkoxide. Both the strong acid sites and the strong base sites were observed to be simultaneously generated on the monoclinic ZrO2 surface.
A Stereoregular Polyphenylacetylene Derivative Bearing an Amino Group as a Probe for Chirality Assignments of Acids by Circular Dichroism
Authors: Yashima Eiji , Maeda Yukio , Okamoto Yoshio
Published: March 2006

Cis-transoidal poly(4-(N,N-diisopropylaminomethyl)phenylacetylene) prepared by polymerization with [Rh(nbd)Cl]2 was found to exhibit an induced circular dichroism in the UV-visible region upon complexation with optically active acids probably due to a prevailing one-handed helix formation of the polymer, the sign of which reflects the absolute configuration of the acids.
1,4-Asymmetric Induction from Chiral δ-Oxygenated Allylic Tin Reagents
Authors: Nishigaichi Yutaka , Yoshikawa Miyuki , Takigawa Yasuyo , Takuwa Akio
Published: March 2006

A new type of asymmetric induction from allylic tin reagents is developed. A chiral allylic tin which has an oxygen substituent (ether or ester) at its δ-position successfully induces a new chirality in a 1,4-induction mode in the reaction with aldehydes via the transmetallation with SnCl4.
Catalytic Dehydrochlorination of 1, 2-Dichloroethane over Pyridine Deposited Pitch-Based Active Carbon Fiber
Authors: Sotowa Chiaki , Kawabuchi Yuji , Mochida Isao
Published: March 2006

Pitch-based active carbon fiber (pitch-ACF) modified by pyridine chemical vapor deposition (CVD) showed excellent catalytic activity for dehydrochlorination of 1, 2-dichloroethane (1, 2-DCE) into vinyl chloride (VC). Compared with polyacrylonitrile-based ACF (PAN-ACF), the present ACF of 2% weight increase by CVD showed long life over 300 h at 360 °C (conversion: ca. 20%; VC selectivity: 99.7%; contact time: 5.8 × 10−3).
Design and Synthesis of a Potential Endoglycosidase Inhibitor: Chemical Conversion of N,N′-Diacetylchitobiose into Novel Pseudodisaccharide Containing a Fivemembered Cyclic N,N-Dimethylguanidine
Authors: Takahashi Shunya , Terayama Hiroyuki , Koshino Hiroyuki , Kuzuhara Hiroyoshi
Published: March 2006

(3aS,4R,5R,6R,6aS)-2-Dimethylamino-3a,5,6,6a-tetrahydro-4-hydroxy-6-hydroxymethyl-4H-cyclopentimidazole-5-yl 2-Acetamido-2-deoxy-β-d-glucopyranoside hydrochloride was designed as a potential inhibitor against endoglycosidases like lysozyme and chitinase, and was synthesized from N,N′-diacetylchitobiose by a series of reactions including radical cyclization of oxime ethers and cyclic guanidine-formation.
Promoting Effects of Carbon Dioxide on Dehydrogenation of Propane over a SiO2-supported Cr2O3 Catalyst
Authors: Takahara Isao , Saito Masahiro
Published: March 2006

The effects of carbon dioxide in the dehydrogenation of C3H8 to produce C3H6 were investigated over several Cr2O3 catalysts supported on Al2O3, active carbon and SiO2. Carbon dioxide exerted promoting effects only on SiO2-supported Cr2O3 catalyst. The promoting effects of carbon dioxide over a Cr2O3/SiO2 catalyst were to enhance the yield of C3H6 and to suppress the catalyst deactivation.
Determination of Memory Life of a Molecular Hysteresis Molecule by Thin Layer CV
Authors: Tomita Atsuko , Sano Mitsuru
Published: March 2006

Thin layer cyclic voltammograms have been measured for (1,5-dithiacyclooctane 1-oxide) bis(pentaammineruthenium(II)) in acetone. The rates of the interconversions of the two intermediate species are determined to be 2 × 10−4 s−1 and 4.4 × 10−4 s−1 by digital simulations to the thin layer voltammograms. The half life of the memory in the molecule is 1600 s.
Cationic Polymerization of Styrene with N-Benzyl Pyridinium Salt. Isolation of Polymeric Cationic Species and Its Application to Block Copolymer Synthesis
Authors: Lee Sang-Bong , Lee Kyu-Wan , Takata Toshikazu , Endo Takeshi
Published: March 2006

A polymeric cationic species (III) could be isolated in the cationic polymerization of styrene with an N-benzyl pyridinium salt (MBCP) by adding the corresponding pyridine (OCP). III is considered to be a terminated end which is active enough to initiate the cationic polymerization since it has still an N-benzyl pyridinium salt structure. Therefore, III could initiate the cationic polymerization of epoxides to give the block copolymers of styrene and epoxides.
A New Stereocontrolled Route to (−)-Shikimic Acid
Authors: Kamikubo Takashi , Ogasawara Kunio
Published: March 2006

A new stereocontrolled route to (−)-shikimic acid, the component of the fruit of shikimi tree, Illicium religiosum, and the key biogenetic precursor of a variety of aromatic natural products, has been developed using the chiral 2,5-cyclohexadienol synthon.
Ion-exchange Reaction of Rubidium Ion in Rb8Nb22O59
Authors: Kumada Nobuhiro , Takagi Masakazu , Kinomura Nobukazu
Published: March 2006

Rubidium ion in Rb8Nb22O59 with a tunnel structure was ion-exchanged with alkaline ions and proton. The ion-exchange with proton was almost complete to yield H7.71Rb0.29Nb22O59·8.9H2O. The degree of ion-exchange with alkaline ions was 79.1%(Na+), 41.8%(K+) and 2.5%(Cs+), and the chemical compositions for the ion-exchanged compounds were Rb1.27Na6.33H0.40Nb22O59·6.1H2O, Rb3.06K3.34H1.60Nb22O59·5.1H2O and Rb6.22Cs0.20H1.58Nb22O59·1.9H2O. The ion-exchange of H7.71Rb0.29Nb22O59·8.9H2O with alkaline ions was also attempted.
Catalytic Stereoselective Synthesis of Pyrimidine 2-Deoxyribonucleosides
Authors: Mukaiyama Teruaki , Hirano Noriyuki , Nishida Minoru , Uchiro Hiromi
Published: March 2006

Highly stereoselective synthesis of β-d-deoxyribonucleosides from 1-O-acetyl-5-O-benzyl-2-deoxy-3-diethylthiocarbamoyl ribofuranoside (3) is performed by the reaction with silylated pyrimidine nucleobases in the presence of a catalytic amount of several Lewis acids.
Isolation of Two Conformationally Frozen Isomers of a Bridged Calix[6]arene
Authors: Saiki Toshiyuki , Okazaki Kei Goto, and Renji
Published: March 2006

Two conformationally frozen isomers of a 1,4-bridged calix[6]arene, one of which is a cone conformer while the other adopts a 1,2,3-alternate conformation, have been isolated by silica-gel chromatogarphy. The interconversion between them was not observed even after heating either of them at 120 °C.
Optional Formation of “Parallel or Antiparallel” β-Sheet-like Structures in (R)-(1-Naphthyl)glycyl-(R)-phenylglycine Crystals
Authors: Akazome Motohiro , Sumikawa Atsuko , Sonobe Ryo-ichi , Ogura Katsuyuki
Published: March 2006

(R)-(1-Naphthyl)glycyl-(R)-phenylglycine forms inclusion compounds with ethers (tetrahydrofuran and diethyl ether) or allylic alcohols (2-propen-1-ol and 2-methyl-2-propen-1-ol). X-ray crystallographic study showed that the dipeptide has the ability to optionally form “parallel or antiparallel” β-sheet-like structures by the choice of ethers or allylic alcohols, respectively, as the guest molecules.
Bulky Thiols and Their Coordination Compounds. An Improvement of the Removal Method of Tetrahydropyranyl Group from Thiols and Its Application for Ligand Syntheses
Authors: Watanabe Hideaki , Ogo Seiji , Yamamura Takeshi
Published: March 2006

The route for the syntheses of alkanthiols having bulky groups at the neighborhood of sulfur atoms was improved, and applied for the preparation of thiol ligands that mimic the cysteine containing metal binding sites in proteins. The new method developed the deprotection of tetrahydropyranyl group from α,α-diphenylalkyl 2-tetrahydropyranyl sulfides.
A Hubris Theory of Entrepreneurship
Authors: Hayward Mathew L. A. , Shepherd Dean A. , Griffin Dale
Published: March 2006

This paper develops a hubris theory of entrepreneurship to explain why so many new ventures are created in the shadow of high venture failure rates: More confident actors are moved to start ventures, and then act on such confidence when deciding how to allocate resources in their ventures. Building on theory and evidence from the behavioral decision-making literature, we describe how founders’ socially constructed confidence affects the manner in which they interpret information about their prior and current ventures. We then link founders’ propensity to be overconfident to their decisions to allocate, use, and attain resources. In our model, founders with greater socially constructed confidence tend to deprive their ventures of resources and resourcefulness and, therefore, increase the likelihood that their ventures will fail.
Introduction to the Focused Issue on Entrepreneurship
Authors: Shane Scott
Published: March 2006

This article is an introduction to the focused issue on entrepreneurship. It provides motivation for greater scholarly investigation of the phenomenon of entrepreneurship, explains the evolution of the focused issue, offers an overview of the seven papers in the issue, and offers the editor’s thoughts on the relationship of the papers in the focused issue to research on entrepreneurship in general.
Erratum—Intuitions About Combining Opinions: Misappreciation of the Averaging Principle
Authors: Larrick Richard P. , Soll Jack B.
Published: March 2006

Due to an error in typesetting, Figures 1–4 and Tables 1–3 were incorrectly labeled as part of this paper in Management Science, Vol. 52, No. 1, January 2006, pp. 111–127. The figures and tables are reprinted correctly below and in the electronic version.
NXY-059: Review of Neuroprotective Potential for Acute Stroke
Authors: Fong Jeffrey J , Rhoney Denise H
Published: March 2006

Objective:

To review available literature on the pharmacology, pharmacokinetics, efficacy, and tolerability of NXY-059, an Investigational agent with a potential role in the treatment of acute stroke.

Data Sources:

Information was obtained from a MEDLINE search (1966–February 2006) of English-language literature utilizing the following search terms: NXY-059, cerovive, nitrones, neuroprotection, free radical trapper, and secondary neurologic injury.

Study Selection and Data Extraction:

Data from animal and human trials were evaluated to summarize the mechanism of action, efficacy, and safety of NXY-059. All published and unpublished trials and abstracts citing NXY-059 were selected.

Data Synthesis:

NXY-059 is an intravenous, nitrone-based, free radical trapping agent in Phase III trials for treatment of acute stroke. In various animal models, NXY-059 has shown reductions in infarct volume and neurologic deficits. Pharmacokinetic studies indicate that NXY-059 displays a predictable pharmacokinetic profile and primarily undergoes renal elimination. Results from 2 Phase II clinical trials showed favorable results for the safety and tolerability of the drug. A recent analysis of one of the Phase III trials showed a statistically significant reduction in the primary outcome of disability after acute stroke in patients who received NXY-059 compared with placebo.

Conclusions:

NXY-059 is a novel agent undergoing worldwide Phase III trials. Initial safety and efficacy data have not revealed any serious adverse events requiring special monitoring and/or precautions, with the exception of drug accumulation in patients with renal insufficiency. The potential benefit of this agent can change the current management algorithm for acute stroke and may represent significant advancement for the care of these patients.
Optic Neuritis with Visual Field Defect—Possible Ibuprofen-Related Toxicity
Authors: Gamulescu Maria-A , Schalke Berthold , Schuierer Gerhard , Gabel Veit-P
Published: March 2006

Objective:

To report a case of optic neuritis with visual field defect associated with ibuprofen.

Case Summary:

A 41-year-old white man developed blurred vision in his right eye and pain with eye and head movements that lasted 2 days after use of ibuprofen 400 mg 3 times daily during the preceding 3 weeks. Medical and family histories were negative for significant related disease. Ophthalmologic examination revealed a marked decrease in visual acuity to 20/200 in the right eye with quadrant visual field loss and absent responses in visual evoked potential (VEP). After discontinuation of the drug and treatment with high-dose intravenous methylprednisolone and subcutaneous low-molecular-weight heparin, the patient's vision improved to 20/70, the visual field defect vanished, and the VEP returned to almost normal values during a 1 year follow-up period. An objective causality assessment revealed that the adverse reaction was possibly related to ibuprofen.

Discussion:

Ocular toxicity with blurred vision and centrocecal visual field defects have been rarely associated with long-term ibuprofen intake. We report a case of retrobulbar optic neuritis with quadrant visual field defect following short-term but regular ibuprofen intake. Although idiopathic optic neuritis cannot be completely ruled out, the absence of other risk factors and additional findings plus the improvement after discontinuation of the drug speak for isolated toxic optic neuritis of the right eye.

Conclusions:

Drug toxicity is an important differential diagnosis in retrobulbar optic neuritis. Clinicians should be aware of the potential optic toxicity, even with short-term use of a drug, and perform a thorough medication history in every patient with visual disturbances without a clear cause.
Self-Reported Adherence in Patients with Asthma
Authors: De Smet Brian D , Erickson Steven R , Kirking Duane M
Published: March 2006

Background:

Not all patients with asthma adhere to their prescribed drug regimens. The Behavioral Model of Health Services Utilization, organized as predisposing, enabling, and need variables, may be useful in identifying variables related to adherent medication-taking behavior.

Objective:

To examine the relationship between predisposing, enabling, and need variables and self-reported adherence with asthma controller drugs.

Methods:

A secondary analysis was conducted from a cross-sectional study using survey and claims data obtained from adults with asthma enrolled in a managed care organization. Independent variables included predisposing (age, gender, race, years with asthma, number of comorbidities, health beliefs), enabling (income, number of metered-dose inhaler [MDI] instructors, inhaler technique, perceived physician access), and need (patient-perceived severity, symptom-derived severity, health-related quality of life). Adherence was measured using a 4 item questionnaire scored as the mean of the responses, with 5 denoting highest adherence. Multivariate regression analysis was used to identify variables with statistically significant relationships to self-reported adherence. Stepwise backward elimination was used, with the final model consisting of variables considered significant at p less than 0.05.

Results:

The 573 respondents (1270 packets sent; 45% response rate) were primarily white (89.5%) and female (71.0%), with an average age of 40.5 ± 12.4 years (mean ± SD) and average asthma duration of 18.3 ± 14.2 years. The mean adherence scale score was 3.7 ± 1.1, with 84.6% indicating some level of nonadherence (score < 5). The final model had an adjusted R2 of 0.26 and Included 6 independent variables. Better adherence was associated with stronger beliefs in the benefits of treatment and trigger avoidance, greater perceived asthma severity, longer asthma duration, more MDI Instructors, and higher scores on the Short-Form 36 mental component summary.

Conclusions:

Complex beliefs, perceptions, and experiences constitute the variables associated with adherent medication-taking behavior. Future longitudinal studies should include these variables to determine the predictive strength of the model.
Cell-Free Plasma DNA: A Marker for Apoptosis during Hemodialysis
Authors: Atamaniuk Johanna , Ruzicka Katharina , Stuhlmeier Karl M , Karimi Alireza , Eigner Manfred , Mueller Mathias M
Published: March 2006

Background: We evaluated whether cell-free plasma DNA might be an appropriate marker for cell damage during hemodialysis (HD) and whether it correlated with annexin V expression and 7-amino-actinomycin D (7AAD) nuclear staining of blood leukocytes.

Methods: Circulating DNA, annexin V, and 7AAD were measured in HD patients before HD, 20 min after start of HD, and after HD had ended. Healthy volunteers provided control measurements. Necrosis and apoptosis were monitored by gel electrophoresis.

Results: Plasma DNA concentrations were not significantly different between controls and patients before HD. Circulating DNA increased significantly (P <0.05) after 20 min of treatment with HD. Post-HD concentrations of DNA were significantly higher compared with pre-HD and controls (P <0.005). Agarose gel electrophoresis showed ladders typical of apoptosis in post-HD samples. Two subpopulations of CD45+ leukocytes were defined by flow cytometry: annexin V+/7AAD+ population for apoptosis, and annexin V+/7AAD− for early apoptosis. Compared with healthy controls, mean fluorescence (MF) of 7AAD+ apoptotic cells in the annexin V+/7AAD+ subpopulation before HD was not significantly increased. HD increased MF of 7AAD+ cells in the annexin V+/7AAD+ subpopulation. In this subpopulation, MF of annexin V+ cells was significantly higher (P <0.01). MF of annexin V+ cells in the annexin V+/7AAD+ subpopulation increased during HD.

Conclusions: During HD, cell-free plasma DNA concentrations, annexin V expression, and 7AAD uptake in leukocytes increases. The increase in plasma DNA, appearing as ladders typical of apoptosis, and the 7AAD uptake in leukocytes demonstrate that the predominant portion of circulating DNA in HD patients originates from apoptotic leukocytes.
cAMP-Dependent Protein Kinase Postsynaptic Localization Regulated by NMDA Receptor Activation through Translocation of an A-Kinase Anchoring Protein Scaffold Protein
Authors: Smith Karen E. , Gibson Emily S. , Dell’Acqua Mark L.
Published: March 2006

NMDA receptor-dependent long-term potentiation and long-term depression (LTD) involve changes in AMPA receptor activity and postsynaptic localization that are in part controlled by glutamate receptor 1 (GluR1) subunit phosphorylation. The scaffolding molecule A-kinase anchoring protein (AKAP)79/150 targets both the cAMP-dependent protein kinase (PKA) and protein phosphatase 2B/calcineurin (PP2B/CaN) to AMPA receptors to regulate GluR1 phosphorylation. Here, we report that brief NMDA receptor activation leads to persistent redistribution of AKAP79/150 and PKA-RII, but not PP2B/CaN, from postsynaptic membranes to the cytoplasm in hippocampal slices. Similar to LTD, AKAP79/150 redistribution requires PP2B/CaN activation and is accompanied by GluR1 dephosphorylation and internalization. Using fluorescence resonance energy transfer microscopy in hippocampal neurons, we demonstrate that PKA anchoring to AKAP79/150 is required for NMDA receptor regulation of PKA-RII localization and that movement of AKAP–PKA complexes underlies PKA redistribution. These findings suggest that LTD involves removal of AKAP79/150 and PKA from synapses in addition to activation of PP2B/CaN. Movement of AKAP79/150–PKA complexes from the synapse could further favor the actions of phosphatases in maintaining dephosphorylation of postsynaptic substrates, such as GluR1, that are important for LTD induction and expression. In addition, our observations demonstrate that AKAPs serve not solely as stationary anchors in cells but also as dynamic signaling components.
Parietal Area 5 and the Initiation of Self-Timed Movements versus Simple Reactions
Authors: Maimon Gaby , Assad John A.
Published: March 2006

The timing of action has been studied extensively in reaction-time tasks in which an abrupt sensory stimulus triggers a movement. In these experiments, neurophysiologists have attempted to explain variability in movement time with variability in neuronal activity. However, in natural settings, movements are not usually triggered by abrupt sensory cues. What underlies the timing of action under such circumstances, when movements are uncoupled or only weakly coupled to abrupt events in the external world? We trained monkeys to perform the same arm movement either in direct reaction to a salient visual event, or as a self-timed action, less coupled to any obvious external trigger. Neurons in cortical area 5 exhibited phasic discharge modulations that were generally comparable for both modes of action, with some neurons increasing and others decreasing their firing rates with movement. For self-timed movements, however, there was an additional, slow ramp-up or ramp-down of activity in the few hundred milliseconds before the phasic discharge. These ramping modulations occurred well before any detectable changes in arm-muscle activity and their time course bore a striking resemblance to activity in the putamen preceding self-timed movements, observed previously. Together, the results suggest a possible mechanism for the internal timing of action within the motor system. In this model, reverberant activity in corticobasal-ganglia circuits reaches a threshold level resulting in much larger perimovement discharges within the same network, consequently driving the initiation of action.
Paired-Pulse Depression at Photoreceptor Synapses
Authors: Rabl Katalin , Cadetti Lucia , Thoreson Wallace B.
Published: March 2006

Synaptic depression produced by repetitive stimulation is likely to be particularly important in shaping responses of second-order retinal neurons at the tonically active photoreceptor synapse. We analyzed the time course and mechanisms of synaptic depression at rod and cone synapses using paired-pulse protocols involving two complementary measurements of exocytosis: (1) paired whole-cell recordings of the postsynaptic current (PSC) in second-order retinal neurons and (2) capacitance measurements of vesicular membrane fusion in rods and cones. PSCs in ON bipolar, OFF bipolar, and horizontal cells evoked by stimulation of either rods or cones recovered from paired-pulse depression (PPD) at rates similar to the recovery of exocytotic capacitance changes in rods and cones. Correlation between presynaptic and postsynaptic measures of recovery from PPD suggests that 80–90% of the depression at these synapses is presynaptic in origin. Consistent with a predominantly presynaptic mechanism, inhibiting desensitization of postsynaptic glutamate receptors had little effect on PPD. The depression of exocytotic capacitance changes exceeded depression of the presynaptic calcium current, suggesting that it is primarily caused by a depletion of synaptic vesicles. In support of this idea, limiting Ca2+influx by using weaker depolarizing stimuli promoted faster recovery from PPD. Although cones exhibit much faster exocytotic kinetics than rods, exocytotic capacitance changes recovered from PPD at similar rates in both cell types. Thus, depression of release is not likely to contribute to differences in the kinetics of transmission from rods and cones.
Stimulus-Dependent Auditory Tuning Results in Synchronous Population Coding of Vocalizations in the Songbird Midbrain
Authors: Woolley Sarah M. N. , Gill Patrick R. , Theunissen Frédéric E.
Published: March 2006

Physiological studies in vocal animals such as songbirds indicate that vocalizations drive auditory neurons particularly well. But the neural mechanisms whereby vocalizations are encoded differently from other sounds in the auditory system are unknown. We used spectrotemporal receptive fields (STRFs) to study the neural encoding of song versus the encoding of a generic sound, modulation-limited noise, by single neurons and the neuronal population in the zebra finch auditory midbrain. The noise was designed to match song in frequency, spectrotemporal modulation boundaries, and power. STRF calculations were balanced between the two stimulus types by forcing a common stimulus subspace. We found that 91% of midbrain neurons showed significant differences in spectral and temporal tuning properties when birds heard song and when birds heard modulation-limited noise. During the processing of noise, spectrotemporal tuning was highly variable across cells. During song processing, the tuning of individual cells became more similar; frequency tuning bandwidth increased, best temporal modulation frequency increased, and spike timing became more precise. The outcome was a population response to song that encoded rapidly changing sounds with power and precision, resulting in a faithful neural representation of the temporal pattern of a song. Modeling responses to song using the tuning to modulation-limited noise showed that the population response would not encode song as precisely or robustly. We conclude that stimulus-dependent changes in auditory tuning during song processing facilitate the high-fidelity encoding of the temporal pattern of a song.
Glutamate Stimulates Oligodendrocyte Progenitor Migration Mediated via an αvIntegrin/Myelin Proteolipid Protein Complex
Authors: Gudz Tatyana I. , Komuro Hitoshi , Macklin Wendy B.
Published: March 2006

In the mammalian CNS, oligodendrocyte precursor cells (OPCs) express most neurotransmitter receptors, but their function remains unclear. The current studies suggest a physiological role for glutamate (AMPA and/or kainate) receptors in OPC migration. AMPA stimulated αvintegrin-mediated OPC migration by increasing both the rate of cell movement and the frequency of Ca2+transients. A protein complex containing the myelin proteolipid protein (PLP) and αvintegrin modulated the AMPA-stimulated migration, and stimulation of OPC AMPA receptors resulted in increased association of the AMPA receptor subunits themselves with the αvintegrin/PLP complex. Thus, after AMPA receptor stimulation, an αvintegrin/PLP/neurotransmitter receptor protein complex forms that reduces binding to the extracellular matrix and enhances OPC migration. To assess the extent to which PLP was involved in the AMPA-stimulated migration, OPCs from the myelin-deficient (MD) rat, which has a PLP gene mutation, were analyzed. OPCs from the MD rat had a normal basal migration rate, but AMPA did not stimulate the migration of these cells, suggesting that the PLP/αvintegrin complex was important for the AMPA-mediated induction. AMPA-induced modulation of OPC migration was abolished by pertussis toxin, although baseline migration was normal. Thus, G-protein-dependent signaling is crucial for AMPA-stimulated migration of OPCs but not for basal OPC migration. Other signaling pathways involved in this AMPA-stimulated OPC migration were also determined. These studies highlight novel signaling determinants of OPC migration and suggest that glutamate could play a pivotal role in regulating integrin-mediated OPC migration.
Binary-Coded Monitoring of a Behavioral Sequence by Cells in the Pre-Supplementary Motor Area
Authors: Shima Keisetsu , Tanji Jun
Published: March 2006

To regulate the temporal structure of a series of behavioral sequences involving multiple actions, it is essential to monitor the progress of the entire behavioral process. To identify the involvement of three cortical motor areas in monitoring behavioral sequences, we examined neuronal activity while monkeys sequentially performed a series of motor tasks in accordance with a predetermined behavioral schedule that included a numerical structure. We found that neurons in the pre-supplementary motor area exhibited activity that appeared to monitor the performance of the behavioral trials in a binary-coded manner. One-half of the activity represented odd-numbered trials within a behavioral sequence, whereas the other one-half represented even-numbered trials. Such neuronal activity, resembling the operation of binary counting elements widely used for constructing artificial computing devices, was rare in the supplementary motor area or in the primary motor cortex.
Tyrosine Phosphatases Regulate AMPA Receptor Trafficking during Metabotropic Glutamate Receptor-Mediated Long-Term Depression
Authors: Moult Peter R. , Gladding Clare M. , Sanderson Thomas M. , Fitzjohn Stephen M. , Bashir Zafar I. , Molnar Elek , Collingridge Graham L.
Published: March 2006

Two forms of long-term depression (LTD), triggered by activation of NMDA receptors (NMDARs) and metabotropic glutamate receptors (mGluRs), respectively, can be induced at CA1 synapses in the hippocampus. Compared with NMDAR-LTD, relatively little is known about mGluR-LTD. Here, we show that protein tyrosine phosphatase (PTP) inhibitors, orthovanadate and phenylarsine oxide, selectively block mGluR-LTD induced by application of the group I mGluR agonist (RS)-3,5-dihydroxyphenylglycine (DHPG-LTD), because NMDAR-LTD is unaffected by these inhibitors. Furthermore, DHPG-LTD measured using whole-cell recording is similarly blocked by either bath-applied or patch-loaded PTP inhibitors. These inhibitors also block the changes in paired-pulse facilitation and coefficient of variation that are associated with the expression of DHPG-LTD. DHPG treatment of hippocampal slices was associated with a decrease in the level of tyrosine phosphorylation of GluR2 AMPA receptor (AMPAR) subunits, an effect blocked by orthovanadate. Finally, in dissociated hippocampal neurons, orthovanadate blocked the ability of DHPG to reduce the number of AMPA receptor clusters on the surface of dendrites. Again, the effects of PTP blockade were selective, because NMDA-induced decreases in surface AMPAR clusters was unaffected by orthovanadate. Together, these data suggest that activation of postsynaptic PTP results in tyrosine dephosphorylation of AMPARs and their removal from the synapse.
Dopamine D3Receptors Regulate GABAAReceptor Function through a Phospho-Dependent Endocytosis Mechanism in Nucleus Accumbens
Authors: Chen Guojun , Kittler Josef T. , Moss Stephen J. , Yan Zhen
Published: March 2006

The dopamine D3receptor, which is highly enriched in nucleus accumbens (NAc), has been suggested to play an important role in reinforcement and reward. To understand the potential cellular mechanism underlying D3receptor functions, we examined the effect of D3receptor activation on GABAAreceptor (GABAAR)-mediated current and inhibitory synaptic transmission in medium spiny neurons of NAc. Application of PD128907 [(4aR,10bR)-3,4a,4,10b-tetrahydro-4-propyl-2H,5H-[1]benzopyrano-[4,3-b]-1,4-oxazin-9-ol hydrochloride], a specific D3receptor agonist, caused a significant reduction of GABAAR current in acutely dissociated NAc neurons and miniature IPSC amplitude in NAc slices. This effect was blocked by dialysis with a dynamin inhibitory peptide, which prevents the clathrin/activator protein 2 (AP2)-mediated GABAAreceptor endocytosis. In addition, the D3effect on GABAAR current was prevented by agents that manipulate protein kinase A (PKA) activity. Infusion of a peptide derived from GABAAR β subunits, which contains an atypical binding motif for the clathrin AP2 adaptor complex and the major PKA phosphorylation sites and binds with high affinity to AP2 only when dephosphorylated, diminished the D3regulation of IPSC amplitude. The phosphorylated equivalent of the peptide was without effect. Moreover, PD128907 increased GABAAR internalization and reduced the surface expression of GABAAreceptor β subunits in NAc slices, which was prevented by dynamin inhibitory peptide or cAMP treatment. Together, our results suggest that D3receptor activation suppresses the efficacy of inhibitory synaptic transmission in NAc by increasing the phospho-dependent endocytosis of GABAAreceptors.
A Medieval Food List from the Monastery of Cluny
Authors: ambrose kirk
Published: March 2006

The sixth-century Rule of Saint Benedict places a premium on silence and proscribes speaking at various times, including during meals. In keeping with the spirit of this mandate, the monks of Cluny, an extremely wealthy and powerful monastery in southern Burgundy, placed a premium on silence from a very early date. The earliest descriptions of a sign language used at Cluny are recorded in two of the monastery's customaries, compiled during the last quarter of the eleventh century. A host of signals are described, but, tellingly, these lists begin with those for food. There were practical reasons for this, namely mandated silence in the refectory, but it also might evidence the relish with which monks enjoyed their food. Indeed, the translation offered here suggests that the monks ate very well.

Because the signals translated here are almost exclusively substantives, it would be nearly impossible to communicate any but the most rudimentary thoughts. That entire conversations were possible by means of gestures is suggested by contemporary criticisms of monks chattering away with hand signals. For our purposes, this would confirm the likely suspicion that the medieval monk enjoyed an even greater variety of foods than indicated here.
Organic in Mexico: A Conversation with Diana Kennedy
Authors: o'neil l. peat
Published: March 2006

Diana Kennedy, culinary historian and cookbook author, explains regional Mexican cuisines to a global audience. L. Peat O'Neil interviews Kennedy and the wide-ranging discussion covers organic agriculture in Mexico, the effects of NAFTA on small farmers, rural activists and the diversity of Mexico's agricultural produce. Kennedy comments on chefs in Mexico City and contemporary Mexican cooking. Kennedy notes that progress in sustainable agriculture is slow in Mexico because of government disinterest and corruption. Kennedy discusses her many visits to the state of Oaxaca, where organic product branding as "Fair Trade organic" first was applied. Her current book project is focused on Oaxaca's regional recipes from remote areas of the state. Kennedy fosters all aspects of sustainable living. Other sources quoted include Pablo Span, a farmer-hotel owner in San Cayetano, Michoacan; and Salvador V. Garibay, a consultant with the Research Institute of Organic Agriculture (FiBL) based in Frick, Switzerland. Garibay works on organic agricultural projects in Mexico and Central America.
Shakespearean Jell-O: Mortality and Malleability in the Kitchen
Authors: wall wendy
Published: March 2006

This study compares the symbolic meanings of gelatin in two eras-the early modern period and the twentieth century. Rather than offering a detailed history of changes in the process of gelatin-making and use over the centuries, I focus on the shifting cultural meanings of this foodstuff at its most dramatic historical divide, the moment when it became a mass produced product and was widely reinterpreted for the public through advertising. In Shakespeare's day, gelatin took meaning from two primary contexts: household labor practices (namely, the violent and highly visible process by which it was made in the kitchen) and contemporary Galenic medical theory, which dictated that extreme emotions could make the body transform into "jelly." As such, gelatin symbolized the frightening alterability of the flesh made visible in daily practice. In the twentieth century, however, Jell-O's plasticity was transformed into a positive virtue, one signaling childhood pleasures, creative potentiality, even patriotism. Its alterability became a hallmark feature linking this edible to dominant myths about the modern American subject.
Simulation of Pediatric Trauma Stabilization in 35 North Carolina Emergency Departments: Identification of Targets for Performance Improvement
Authors: Hunt Elizabeth A. , Hohenhaus Susan M. , Luo Xuemei , Frush Karen S.
Published: March 2006

OBJECTIVE. Trauma is the leading cause of death in children. Most children present to community hospital emergency departments (EDs) for initial stabilization. Thus, all EDs must be prepared to care for injured children. The objectives of this study were to (1) characterize the quality of trauma stabilization efforts in EDs and (2) identify targets for educational interventions.

METHODS. This was a prospective observational study of simulated trauma stabilizations, that is, “mock codes,” at 35 North Carolina EDs. An evaluation tool was created to score each mock code on 44 stabilization tasks. Primary outcomes were (1) interrater reliability of tool, (2) overall performance by each ED, and (3) performance per stabilization task.

RESULTS. Evaluation-tool interrater reliability was excellent. The median number of stabilization tasks that needed improvement by the EDs was 25 (57%) of 44 tasks. Although problems were numerous and varied, many EDs need improvement in tasks uniquely important and/or complicated in pediatric resuscitations, including (1) estimating a child's weight (17 of 35 EDs [49%]), (2) preparing for intraosseous needle placement (24 of 35 [69%]), (3) ordering intravenous fluid boluses (31 of 35 [89%]), (4) applying warming measures (34 of 35 [97%]), and (5) ordering dextrose for hypoglycemia (34 of 35 [97%]).

CONCLUSIONS. This study used simulation to identify deficiencies in stabilization of children presenting to EDs, revealing that mistakes are ubiquitous. ED personnel were universally receptive to feedback. Future research should investigate whether interventions aimed at improving identified deficiencies can improve trauma stabilization performance and, ultimately, the outcomes of children who present to EDs.
Volume Matters: Physician Practice Characteristics and Immunization Coverage Among Young Children Insured Through a Universal Health Plan
Authors: Guttmann Astrid , Manuel Doug , Dick Paul T. , To Teresa , Lam Kelvin , Stukel Therese A.
Published: March 2006

OBJECTIVES. We studied the association between immunization coverage for a cohort of 2-year-old children covered by a universal health insurance plan and pediatric provider and other health services characteristics.

METHODS. We assembled a cohort of 101570 infants born in urban areas in Ontario, Canada, between July 1, 1997, and June 31, 1998. Children were considered to have up-to-date (UTD) immunization coverage if they had ≥5 immunizations by 2 years of age, ie, the recommended 3 doses and 1 booster of diphtheria-polio-tetanus-pertussis/Haemophilus influenzae type b vaccine and 1 dose of measles-mumps-rubella vaccine. Provider practice characteristics were derived from outpatient billing records, and 1996 census data were used to derive neighborhood income quintiles. The association between UTD immunization status and provider characteristics was assessed with multilevel regression models, controlling for patient characteristics.

RESULTS. Overall, the rate of complete UTD immunization coverage was low (66.3%) despite a large number of primary care visits (median: 19 visits). Children whose usual provider had a low volume of pediatric primary care were less than one half as likely to be UTD. Other factors associated with not being UTD included very low continuity of care, low continuity of care, and usual provider in practice for <5 years. With adjustment for patient and provider characteristics, there was no difference in immunization coverage for general practitioners versus pediatricians. Children from low-income neighborhoods were less likely to be UTD.

CONCLUSIONS. Despite universal access to primary care services, rates of complete immunization coverage among 2-year-old children in Ontario are low. Because visit rates are high, primary care reform should include interventions directed at provider immunization practices to reduce missed opportunities.
Improving the Quality of End-of-Life Care in the Pediatric Intensive Care Unit: Parents' Priorities and Recommendations
Authors: Meyer Elaine C. , Ritholz Marilyn D. , Burns Jeffrey P. , Truog Robert D.
Published: March 2006

OBJECTIVE. Despite recognition that dying children and their families have unique palliative care needs, there has been little empirical inquiry of parent perspectives to improve the quality of end-of-life care and communication. The purpose of this study was to identify and describe the priorities and recommendations for end-of-life care and communication from the parents' perspective.

METHODS. This was a qualitative study based on parental responses to open-ended questions on anonymous, self-administered questionnaires, conducted at 3 pediatric ICUs in Boston, Massachusetts. Fifty-six parents whose children had died in PICUs after withdrawal of life support participated in this study. We measured parent-identified priorities for end-of-life care and communication.

RESULTS. Parents identified 6 priorities for pediatric end-of-life care including honest and complete information, ready access to staff, communication and care coordination, emotional expression and support by staff, preservation of the integrity of the parent-child relationship, and faith.

CONCLUSIONS. Parental priorities and recommendations offer simple yet compelling guidance to improve pediatric end-of-life clinical practice and research.
Do Changes in Body Mass Index Percentile Reflect Changes in Body Composition in Children? Data From the Fels Longitudinal Study
Authors: Demerath Ellen W. , Schubert Christine M. , Maynard L. Michele , Sun Shumei S. , Chumlea W. Cameron , Pickoff Arthur , Czerwinski Stefan A. , Towne Bradford , Siervogel Roger M.
Published: March 2006

OBJECTIVE. Our aim was to examine the degree to which changes in BMI percentile reflect changes in body fat and lean body mass during childhood and how age and gender affect these relationships.

METHODS. This analysis used serial data on 494 white boys and girls who were aged 8 to 18 years and participating in the Fels Longitudinal Study (total 2319 observations). Total body fat (TBF), total body fat-free mass (FFM), and percentage of body fat (%BF) were determined by hydrodensitometry, and then BMI was partitioned into its fat and fat-free components: fat mass index (FMI) and FFM index (FFMI). We calculated predicted changes (Δ) in FMI, FFMI, and %BF for each 10-unit increase in BMI percentile using mixed-effects models.

RESULTS. FFMI had a linear relationship with BMI percentile, whereas FMI and %BF tended to increase dramatically only at higher BMI percentiles. Gender and age had significant effects on the relationship between BMI percentile and FFMI, FMI, and %BF. Predicted Δ%BF for boys 13 to 18 years of age was negative, suggesting loss of relative fatness for each 10-unit increase in BMI percentile.

CONCLUSIONS. In this longitudinal study of white children, FFMI consistently increased with BMI percentile, whereas FMI and %BF had more complicated relationships with BMI percentile depending on gender, age, and whether BMI percentile was high or low. Our results suggest that BMI percentile changes may not accurately reflect changes in adiposity in children over time, particularly among male adolescents and children of lower BMI.
Risks for Low Intellectual Performance Related to Being Born Small for Gestational Age Are Modified by Gestational Age
Authors: Bergvall Niklas , Iliadou Anastasia , Johansson Stefan , Tuvemo Torsten , Cnattingius Sven
Published: March 2006

OBJECTIVE. We sought to study whether the association between being born small for gestational age and risk for low intellectual performance was modified by gestational age.

METHODS. A population-based cohort study was conducted of 352125 boys who were born between 28 and 43 completed weeks of gestation from 1973 to 1981 in Sweden. Risk for low intellectual performance at military conscription, estimated as odds ratios with 95% confidence intervals was measured.

RESULTS. Compared with men who were born preterm (28–36 weeks) and had normal birth weight for gestational age, men who were born preterm and had a very low birth weight for gestational age were not at increased risk for low intellectual performance. In contrast, men who were born preterm with a very short birth length or a very small head circumference for gestational age faced a near doubled risk for low intellectual performance compared with their appropriate peers. Among men who were born at term (37–41 weeks), risk for low intellectual performance was increased among those with very or moderately small birth weight, birth length, or head circumference for gestational age.

CONCLUSIONS. During early stages of gestation, growth in length and head circumference may be more important for intellectual development than weight increase. Future studies on size at birth and intellectual performance should consider also including anthropometric measurements other than birth weight.
A Randomized, Controlled Trial of Removable Splinting Versus Casting for Wrist Buckle Fractures in Children
Authors: Plint Amy C. , Perry Jeffrey J. , Correll Rhonda , Gaboury Isabelle , Lawton Louis
Published: March 2006

OBJECTIVE. Wrist buckle fractures are a frequent reason for emergency department visits. Although textbooks recommend 2 to 4 weeks of immobilization in a short arm cast, management varies. Treatment with both casts and splints is common, and length of immobilization varies. The objective was to determine if children with distal radius and/or ulna buckle fractures treated with a removable splint have better physical functioning than those treated with a short arm cast for 3 weeks.

METHODS. This was a randomized, controlled trial in the emergency department of an academic, tertiary care children's hospital. Participants were children 6 to 15 years of age with distal radius and/or ulna buckle fractures who were randomly assigned to treatment with a short arm cast for 3 weeks or a removable splint. Cast removal was at 3 weeks. A validated self-reported outcome tool, the Activities Scales for Kids performance version (ASKp), was used to measure physical functioning over a 4-week period. The main outcome was the ASKp score at 14 days postinjury.

RESULTS. We randomly assigned 113 patients, and 87 were included in the final analysis: 42 in the splint group and 45 in the cast group. Study groups were similar in age, gender, bone fractured, and dominant hand injured. There were significant differences in ASKp score at day 14 and change in ASKp from baseline at days 14 and 20, indicating better functioning in the splint group. Splinted children had less difficulty with bathing throughout the entire study. There were no significant differences in pain between groups as measured by visual analog scale. There were no refractures.

CONCLUSIONS. Children treated with removable splinting have better physical functioning and less difficulty with activities than those treated with a cast.