bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cortical Inputs and GABA Interneurons Imbalance Projection Neurons in the Striatum of Parkinsonian Rats
Authors: Mallet Nicolas , Ballion Bérangère , Le Moine Catherine , Gonon François 
Published: April 2006

The striatum receives massive cortical excitatory inputs and is densely innervated by dopamine. Striatal projection neurons form either the direct or indirect pathways. Models of Parkinson's disease propose that dopaminergic degeneration imbalances both pathways, although direct electrophysiological evidence is lacking. Here, striatal neurons were identified by electrophysiological criteria and Neurobiotin labeling combined with either immunohistochemistry orin situhybridization. Their spontaneous discharge activity and spike response to cortical stimulation were recordedin vivoin anesthetized rats rendered hemi-parkinsonian by 6-hydroxydopamine. We showed that striatonigral neurons (direct pathway) were inhibited whereas striatopallidal neurons (indirect pathway) were activated by dopaminergic lesion. We also identified, with antidromic stimulations, corticostriatal neurons that preferentially innervate striatonigral or striatopallidal neurons and showed that dopaminergic depletion selectively decreased the spontaneous activity of the former. Therefore, dopamine degeneration induces a cascade of imbalances that spread out of the basal ganglia and affect the whole basal ganglia-thalamo-cortical circuits.Fast-spiking GABA interneurons provide potent feedforward inhibition of striatal projection neurons. We showed here that these interneurons narrowed the time window of the responses of projection neurons to cortical stimulation. In the dopamine-depleted striatum, because the intrinsic activity of these interneurons was not altered, their feedforward inhibition worsened the striatal imbalance. Indeed, the time window of the evoked responses was narrower for striatonigral neurons and wider for striatopallidal neurons. Therefore, after dopaminergic depletion, cortical inputs and GABA interneurons might imbalance striatal projection neurons and represent two novel nondopaminergic mechanisms that might secondarily contribute to the pathophysiology of Parkinson's disease.
Somatosensory Cells in Area PEc of Macaque Posterior Parietal Cortex
Authors: Breveglieri Rossella , Galletti Claudio , Gamberini Michela , Passarelli Lauretta , Fattori Patrizia 
Published: April 2006

PEc is an area defined on cytoarchitectural grounds, located in the posterior part of the superior parietal lobule of macaque brain (Pandya and Seltzer, 1982). The aim of this work was to assess whether passive somatosensory stimulation elicited responses in PEc neurons. Extracellular recordings were performed in three awakeMacaca fascicularis. Passive somatosensory stimulation was performed in darkness, and eye movements were monitored continuously. Recording sites were assigned to different areas according to the cytoarchitectonic criteria described by Pandya and Seltzer (1982) and Luppino et al. (2005). Only recording sites within the limits of the cytoarchitecturally defined area PEc were taken into account in this work.Of 147 PEc cells, 83 (56%) were modulated by passive somatosensory stimulation. The majority of them (73%) responded to joint rotations, and 24% responded to tactile skin stimulation. The majority of PEc somatosensory responses (90%) were evoked by contralateral stimulation. Joint-modulated cells were mostly activated by the upper limbs (82%). The majority of tactile receptive fields (61%) were located on the arms, and a minority was located on the legs and trunk. One-half of PEc somatosensory cells were polysensory, because they were sensitive to visual stimulation. The majority of PEc somatosensory cells were activated by active reaching movements. Somatosensory cells, somatosensory submodalities, and body part representations were not clustered in PEc subregions; in other words, PEc does not show a somatotopic organization. Although the caudal sector of the superior parietal lobule has been traditionally considered as a somatosensory area, this is the first demonstration of the presence of somatosensory cells in this cortical region.
Somatic Sensation of Hand-Object Interactive Movement Is Associated with Activity in the Left Inferior Parietal Cortex
Authors: Naito Eiichi , Ehrsson H. Henrik 
Published: April 2006

Manipulation of objects and tool-use are known to be controlled by a network of frontal motor and parietal areas. Here, we investigate which of these areas are associated with the somatic sensation of hand-object interactive movement using functional magnetic resonance imaging.To dissociate the sensation of movement from the motor control commands, we used a new kinesthetic illusion. Twelve blindfolded right-handed participants placed the palm of their right or left hand on an object (a ball). Simultaneously, we vibrated the tendon of the wrist extensor muscle. This elicited the illusion that the wrist is flexing and the touched object is also moving along with the hand (hand-object illusion). As controls, we vibrated the skin surface over the nearby bone, which does not elicit any illusions, or we vibrated the tendon when the hand did not touch the object, which only generates the illusory flexion of the hand.We found that the hand-object illusion specifically activated the left inferior parietal lobule (IPL) (supramarginal gyrus and parietal operculum, including cytoarchitectonic areas ip1 and op1) and area 44. The left IPL was activated both during the hand-object illusions with the right and left hands, and the activity was greater than in the right corresponding parietal region, suggesting a dominant role of the left hemisphere.We conclude that the left IPL is involved in the somatic perception of hand-object interactive movement and suggest that the underlying mechanism is the somatic integration of internal information about the body and external information about the object.
Structural Determinants of M-Type KCNQ (Kv7) K+Channel Assembly
Authors: Schwake Michael , Athanasiadu Despina , Beimgraben Christian , Blanz Judith , Beck Christian , Jentsch Thomas J. , Saftig Paul , Friedrich Thomas 
Published: April 2006

The ability of KCNQ (Kv7) channels to form hetero-oligomers is of high physiological importance, because heteromers of KCNQ3 with KCNQ2 or KCNQ5 underlie the neuronal M-current, which modulates neuronal excitability. In KCNQ channels, we recently identified a C-terminal subunit interaction (si) domain that determines their subunit-specific assembly. Within thissidomain, there are two motifs that comprise ∼30 amino acid residues each and that exhibit a high probability for coiled-coil formation. Transfer of the first or the second coiled-coil (TCC) domain from KCNQ3 into the KCNQ1 scaffold resulted in chimeras KCNQ1(TCC1)Q3 and KCNQ1(TCC2)Q3, both of which coimmunoprecipitated with KCNQ2. However, only KCNQ1(TCC2)Q3 enhanced KCNQ2 currents and surface expression or exerted a strong dominant-negative effect on KCNQ2. Deletion of TCC2 within KCNQ2 yielded functional homomeric channels but prevented the current augmentation measured after coexpression of KCNQ2 and KCNQ3. In contrast, deleting TCC1 within KCNQ2 did not give functional homomeric KCNQ2 or heteromeric KCNQ2/KCNQ3 channels. Mutations that disrupted the predicted coiled-coil structure of TCC1 in KCNQ2 or KCNQ3 abolished channel activity after expressing these constructs singly or in combination, whereas helix-breaking mutations in TCC2 of KCNQ2 gave functional homomeric channels but prevented the heteromerization with KCNQ3. In contrast, KCNQ3 carrying a coiled-coil disrupting mutation in TCC2 hetero-oligomerized with KCNQ2.Our data suggest that the TCC1 domains of KCNQ2 and KCNQ3 are required to form functional homomeric as well as heteromeric channels, whereas both TCC2 domains facilitate an efficient transport of heteromeric KCNQ2/KCNQ3 channels to the plasma membrane.
Regulation of
DNA
methylation by
Dnmt
3
L
Authors: Bourc'his Déborah , Bestor Timothy H. 
Published: April 2006

Abstract

Imprinted genes and transposable elements simultaneously undergo de novo methylation during mammalian gametogenesis. Dnmt3L, a catalytically inactive DNA‐methyltransferase homolog, regulates this process by directing the methylation machinery to target maternally imprinted genes in growing oocytes, and transposable elements and to a lower extent paternally imprinted genes in perinatal prospermatogonia. Engineered mutations in the
Dnmt3L
gene highlighted the importance of germ line methylation in reproduction and development. Failure to methylate maternally imprinted genes in
Dnmt3L
‐mutant female germ cells resulted in a loss of allele‐specific expression of these genes in the heterozygous progeny and caused maternal‐effect lethality. Dnmt3L‐deficient male germ cells showed demethylation and mass reactivation of retroposons associated with an interruption of spermatogenesis at the pachytene stage due to anomalies in homologous chromosome pairing. Further studies of the methylation regulator Dnmt3L should provide important clues about the mechanisms that establish methylation patterns in the mammalian genome.
L
isteriae
Authors: Buchrieser Carmen , Glaser Philippe 
Published: April 2006

Abstract

The genus
Listeria
contains six species of ubiquitous environmental bacteria.
Listeria monocytogenes
is an invasive, opportunistic, food‐borne pathogen and
Listeria ivanovii
, a pathogen that specifically affects ruminants. The
Listeria
genomes encode a high number of surface, transport, and regulatory proteins. Comparison of the five genomes revealed a high conservation in genome organization, size, and gene content. Strain specific differences are present, probably related to niche adaptation and different virulence properties. However known virulence factors necessary for human infection are conserved among all

L. monocytogenes

strains.
Advances of
LC
‐
MS
and
CZE
‐
MS
in proteome analysis
Authors: Lee Hookeun , Aebersold Ruedi 
Published: April 2006

Abstract
The combination of high‐performance separation techniques and mass spectrometry (MS) has had a significant impact on proteomics over the past decade. High‐resolution separation of peptides prior to MS is essential to improve sensitivity, speed, and throughput of the analysis of peptides that originate from the global digestion of complex protein mixtures. This article will review recent advances of microcapillary chromatography and capillary zone electrophoresis (CZE) in the field of proteomics.
Analyzing proteomic, genomic and transcriptomic elemental compositions to uncover the intimate evolution of biopolymers
Authors: Baudouin‐Cornu Peggy , Bragg Jason G. 
Published: April 2006

Abstract
The main elemental constituents of living organisms are subjected to biogeochemical cycles that result in both temporal and spatial variation in their abundance. Since organisms have to find their molecular constituents in the environment, this variability may affect the synthesis of biopolymers, in a manner that depends on their atomic (elemental) composition. For example, a biopolymer that is rich in a particular element may become more difficult to synthesize when that element is scarce. Indeed, several studies have now demonstrated that nutritional constraints can shape the evolution of biopolymers specifically in relation to their atomic composition; that is, at a more intimate scale than amino acid or base composition. We discuss these studies, and propose that the increasing availability of data on genomes, proteomes, and RNAs be exploited to study adaptive imprints in the atomic composition of biopolymers, and the factors driving these adaptations.
Polyelectrolyte Brushes as Ink Nanoreservoirs for Microcontact Printing of Ionic Species with Poly(dimethyl siloxane) Stamps
Authors: Azzaroni O. , Moya S. E. , Brown A. A. , Zheng Z. , Donath E. , Huck W. T. S. 
Published: April 2006

AbstractIn this work a new variation of microcontact printing is described, which is used to transfer chemical patterns onto different substrates. The approach is based on the use of conventional elastomeric stamps modified with polyelectrolyte brushes. It is demonstrated that, by using stamps modified with brushes acting as preconcentrating/sorbent nanolayers, it is possible to control the uptake of aqueous inks containing ionic species. This controlled uptake can be easily used for site‐selective delivery of the loaded species by means of soft lithography. The potential of this approach is demonstrated by creating patterned counterion domains in a flat polyelectrolyte brush and by promoting a site‐selective metallization through galvanic displacement reactions with reactive species.
Wavelength and Intensity Multiplexing of Metal Nanoparticles for the Fabrication of Multicolored Micro‐ and Nanospheres
Authors: Lim Y. T. , Kim J. K. , Shin Y. B. , Chung B. H. 
Published: April 2006

AbstractMulticolored micro‐ and nanospheres have been successfully fabricated by a novel method that was developed to broaden the selection of colors available in the application of metal nanoparticles (NPs). The colors of the metal NPs have been systematically tuned over a wide spectral range by wavelength and intensity multiplexing of three‐colored NPs. Multicolor polystyrene micro‐ and nanospheres could be fabricated by combining the systematic color tuning of metal NPs and self‐assembly of metal NPs on the surfaces of the polymer spheres. The agglomeration of metal NPs on the surfaces of polymer spheres could be prevented by optimizing the concentration of the metal NPs and the reaction pH.
High Carrier Density and Metallic Conductivity in Poly(3‐hexylthiophene) Achieved by Electrostatic Charge Injection
Authors: Panzer M. J. , Frisbie C. D. 
Published: April 2006

AbstractThe use of electrostatic charge injection (i.e., the transverse field effect) to induce both very large two‐dimensional hole densities (∼ 1015 charges cm–2) and metallic conductivities in poly(3‐hexylthiophene) (P3HT) is reported. Films of P3HT are electrostatically gated by a solution‐deposited polymer‐electrolyte gate dielectric in a field‐effect‐transistor configuration. Exceptionally high hole field‐effect mobilities (up to 0.7 cm2 V–1 s–1) are measured concurrently with large hole densities, resulting in an extremely large sheet conductance of 200 μS sq.–1. The large room‐temperature conductivity of 1000 S cm–1 together with the very low measured activation energies (0.7–4 meV) suggest that the metal–insulator transition in P3HT is achieved. A maximum in sheet conductance versus charge density is also observed, which may result from near‐filling of the valence band or from charge correlations that lower the carrier mobility. Importantly, the large hole densities in P3HT are achieved using capacitive coupling between the polymer‐electrolyte gate dielectric and P3HT (i.e., the field effect) and not via chemical or electrochemical doping. Electrostatic control of carrier density up to 1015 charges cm–2 (∼ 1022 charges cm–3) opens opportunities to explore systematically the importance of charge‐correlation effects on transport in conjugated polymers without the structural rearrangement associated with chemical or electrochemical doping.
The seasonal forecast of electricity demand: a hierarchical Bayesian model with climatological weather generator
Authors: Pezzulli Sergio , Frederic Patrizio , Majithia Shanti , Sabbagh Sal , Black Emily , Sutton Rowan , Stephenson David 
Published: April 2006

AbstractIn this paper we focus on the one year ahead prediction of the electricity peak‐demand daily trajectory during the winter season in Central England and Wales. We define a Bayesian hierarchical model for predicting the winter trajectories and present results based on the past observed weather. Thanks to the flexibility of the Bayesian approach, we are able to produce the marginal posterior distributions of all the predictands of interest. This is a fundamental progress with respect to the classical methods. The results are encouraging in both skill and representation of uncertainty. Further extensions are straightforward at least in principle. The main two of those consist in conditioning the weather generator model with respect to additional information like the knowledge of the first part of the winter and/or the seasonal weather forecast. Copyright © 2006 John Wiley & Sons, Ltd.
Posterior sampling with constructed likelihood functions: an application to flowgraph models
Authors: J. Williams Brian , V. Huzurbazar Aparna 
Published: April 2006

AbstractWe consider posterior sampling in situations where data are incomplete in such a way that likelihood functions corresponding to portions of the data must be constructed. Slice sampling, a recently developed Markov chain Monte Carlo method, makes such computation feasible. Such situations arise in the context of stochastic networks where an overall predictive waiting time is comprised of convolutions and finite mixtures of individual transitions and portions of the individual transition information is unobserved for some records. We present applications involving flowgraph models in the reliability setting; however, the methodology presented is relevant to any application where likelihood functions cannot be specified in closed form but can be evaluated numerically. Copyright © 2006 John Wiley & Sons, Ltd.
A Bayesian analysis of clusters of extreme losses
Authors: Vaz de Melo Mendes Beatriz 
Published: April 2006

AbstractOccasional short range dependence in a claim generating process, probably induced by some subordinated process, may result in clusters of extreme losses. Under such circumstances, the iid assumption for the exceedances may not hold anymore. For a given value of the retention level, we overcome this difficulty by applying an empirical rule for cluster definition and aggregating the excesses within clusters. This modelling strategy is compared to the classical random sum of excess losses model based on the iid assumption. The usual discrete probability models and an extreme value distribution from the Pareto family are assumed, respectively, for the counting processes and the severities. Bayesian techniques are then used to obtain a predictive distribution of the annual excess claim amount. Maximum likelihood estimates are also computed and compared. We illustrate using a fire insurance claims data. The Bayesian approach provided more conservative point and interval estimates for the statistical premium. Copyright © 2006 John Wiley & Sons, Ltd.
Experimental design principles for isotopically instationary 13C labeling experiments
Authors: Nöh Katharina , Wiechert Wolfgang 
Published: April 2006

Abstract13C metabolic flux analysis (MFA) is a well‐established tool in Metabolic Engineering that found numerous applications in recent years. However, one strong limitation of the current method is the requirement of an—at least approximate—isotopic stationary state at sampling time. This requirement leads to a principle lower limit for the duration of a 13C labeling experiment. A new methodological development is based on repeated sampling during the instationary transient of the 13C labeling dynamics. The statistical and computational treatment of such instationary experiments is a completely new terrain. The computational effort is very high because large differential equations have to be solved and, moreover, the intracellular pool sizes play a significant role. For this reason, the present contribution works out principles and strategies for the experimental design of instationary experiments based on a simple example network. Hereby, the potential of isotopically instationary experiments is investigated in detail. Various statistical results on instationary flux identifiability are presented and possible pitfalls of experimental design are discussed. Finally, a framework for almost optimal experimental design of isotopically instationary experiments is proposed which provides a practical guideline for the analysis of large‐scale networks. © 2006 Wiley Periodicals, Inc.
A validated high‐performance liquid chromatographic assay for determination of lumiracoxib in human plasma
Authors: Cheremina Olga , Brune Kay , Hinz Burkhard 
Published: April 2006

AbstractLumiracoxib {2‐[(2‐fluoro‐6‐chlorophenyl)amino]‐5‐methyl‐benzeneacetic acid} is a highly selective and potent cyclooxygenase‐2 (COX‐2) inhibitor, which is chemically distinct from other coxibs in that it contains a carboxylic group and is weakly acidic. In the present study, a liquid–liquid extraction‐based reversed‐phase HPLC method with UV detection was validated and applied for the analysis of lumiracoxib in human plasma. The analyte was separated on a reversed‐phase column with acetonitrile and 0.05% trichloracetic acid in water (35:65, v/v) as mobile phase at a flow rate of 1 mL/min, and UV detection at 270 nm. The retention times for lumiracoxib and niflumic acid (internal standard) were 16.9 and 10.4 min, respectively. The validated quantitation range for lumiracoxib was 10–10,000 ng/mL. The developed procedure was applied to assess the pharmacokinetics of lumiracoxib following administration of a single oral 200 mg dose to a healthy male volunteer. Copyright © 2006 John Wiley & Sons, Ltd.
Twin Probes as a Novel Tool for the Detection of Single‐Nucleotide Polymorphisms
Authors: Ergen Erhan , Weber Markus , Jacob Josemon , Herrmann Andreas , Müllen Klaus 
Published: April 2006

AbstractSingle‐nucleotide polymorphisms (SNPs) are the most common form of DNA sequence variation. There is a strong interest from both academy and industry to develop rapid, sensitive and cost effective methods for SNP detection. Here we report a novel structural concept for DNA detection based on fluorescence dequenching upon hybridization. The so‐called “twin probe” consists of a central fluorene derivative as fluorophore to which two identical oligonucleotides are covalently attached. This probe architecture is applied in homogeneous hybridization assays with subsequent fluorescence spectroscopic analysis. The bioorganic hybrid structure is well suited for sequence specific DNA detection and even SNPs are identified with high efficiency. Additionally, the photophysical properties of the twin probe were investigated. The covalent attachment of two single stranded oligonucleotides leads to strong quenching of the central fluorescence dye induced by the nucleobases. The twin probe is characterized by supramolecular aggregate formation accompanied by red‐shifted emission and broad fluorescence spectra.
Structure and Magnetic Properties of the Orthorhombic n = 2 Ruddlesden—Popper Phases Sr3Co2O5+δ (δ = 0.91, 0.64 and 0.38).
Authors: Viciu L. , Zandbergen H. W. , Xu Q. , Huang Q. , Lee M. , Cava R. J. 
Published: April 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Phase Transitions in K3AlF6.
Authors: Abakumov Artem M. , Rossell Marta D. , Alekseeva Anastasiya M. , Vassiliev Sergey Yu. , Mudrezova Svetlana N. , Van Tendeloo Gustaaf , Antipov Evgeny V. 
Published: April 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Oxide Foams for the Synthesis of High‐Surface‐Area Vanadium Nitride Catalysts.
Authors: Krawiec Piotr , De Cola Patrizia Laura , Glaeser Roger , Weitkamp Jens , Weidenthaler Claudia , Kaskel Stefan 
Published: April 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Capturing an Aluminophosphite Intermediate in the New Route of Synthesizing Zeolite‐Like Aluminophosphates.
Authors: Li Niu , Ma Yanfeng , Xiang Shouhe , Guan Naijia 
Published: April 2006

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.