bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interconnected cortical networks between primary somatosensory cortex septal columns and posterior parietal cortex in rat
Authors: Lee Taehee , Alloway Kevin D. , Kim Uhnoh 
Published: December 2010

AbstractVisual and somesthetic cues are used for spatial processing in the posterior parietal cortex (PPC) of the mammalian brain. In rats, somatic information collected by the mystacial whiskers is critically involved in constructing a neural representation of the external space. Here, we delineated the topography of the cortical pathway from primary somatosensory cortex (SI) that may deliver vibrissal cues to PPC for spatial processing. For anterograde tracing, we made small injections of biotinylated dextran amine (BDA) into SI barrel cortex. The injections in the regions directly above the septal compartments produced dense terminals in PPC, whereas injections above the center of the barrels resulted in sparse terminals. For retrograde tracing, we made large injections of cholera toxin subunit B (CtB) in PPC. Retrogradely labeled neurons within SI barrel cortex formed multiple, parallel strips. In layer IV, these strips of labeled neurons were confined within the septal rows, extending from barrel arc position 0 to 5. In the extragranular layers, labeled neurons were clustered primarily within the vertical extensions of the septal rows and extended to the edges of neighboring barrel columns. Based on these findings, in which SI projections to PPC arise mainly from the septal columns, we hypothesize that septal columns may form interconnected cortical networks that engage in spatial information processing contingent on somestheic cues. J. Comp. Neurol. 519:405–419, 2011. © 2011 Wiley‐Liss, Inc.
Molecular Adsorbates at Single‐Crystal Platinum‐Group Metals and Bimetallic Surfaces
Authors: Baltruschat Helmut , Ernst Siegfried 
Published: December 2010

AbstractThe surface orientation of Pt‐group metals determines the kind of organic species (such as CO, benzene and ethene) that will adsorb on them as well as the prevailing reaction channels. Pt and Pd as well as (sub)monolayers of them on Au are compared, including mono‐ and multiatomic rows of Pd on stepped Au surfaces. In general, Pd is less active for oxidation or hydrogenation of the adsorbates. Desorption of the intact molecule is favored because of a lower adsorption strength.
FRET Microscopy in 2010: The Legacy of Theodor Förster on the 100th Anniversary of his Birth
Authors: Sun Yuansheng , Wallrabe Horst , Seo Soo‐Ah , Periasamy Ammasi 
Published: December 2010

AbstractTheodor Förster would have been 100 years old this year, and he would have been astounded to see the impact of his scientific achievement, which is still evolving. Combining his quantitative approach of (Förster) resonance energy transfer (FRET) with state‐of‐the‐art digital imaging techniques allows scientists to breach the resolution limits of light (ca. 200 nm) in light microscopy. The ability to deduce molecular or particle distances within a range of 1–10 nm in real time and to prove or disprove interactions between two or more components is of vital interest to researchers in many branches of science. While Förster’s groundbreaking theory was published in the 1940s, the availability of suitable fluorophores, instruments, and analytical tools spawned numerous experiments in the last 20 years, as demonstrated by the exponential increase in publications. These cover basic investigation of cellular processes and the ability to investigate them when they go awry in pathological states, the dynamics involved in genetics, and following events in environmental sciences and methods in drug screening. This review covers the essentials of Theodor Förster’s theory, describes the elements for successful implementation of FRET microscopy, the challenges and how to overcome them, and a leading‐edge example of how Förster’s scientific impact is still evolving in many directions. While this review cannot possibly do justice to the burgeoning field of FRET microscopy, a few interesting applications such as three‐color FRET, which greatly expands the opportunities for investigating interactions of cellular components compared with the traditional two‐color method, are described, and an extensive list of references is provided for the interested reader to access.
Control of Cross Relaxation of Multiple‐Quantum Coherences Induced by Fast Chemical Exchange under Heteronuclear Double‐Resonance Irradiation
Authors: Ulzega Simone , Salvi Nicola , Segawa Takuya F. , Ferrage Fabien , Bodenhausen Geoffrey 
Published: December 2010

AbstractA fully analytical description of the control of the cross‐correlated cross relaxation of multiple‐quantum coherences in the presence of local dynamics under heteronuclear double‐resonance radio‐frequency (RF) irradiation is presented. The contribution of chemical exchange to relaxation can be partly or fully quenched by RF fields. We assume a correlated two‐site chemical exchange model with arbitrary populations, and show that in the limit of fast exchange the dependence of the effective multiple‐quantum cross‐relaxation rate on the applied RF amplitude can be described by a compact analytical expression. Numerical simulations and preliminary experiments support our theoretical results. The relaxation dispersion as a function of RF amplitude can provide accurate information on the kinetics of correlated processes.
Chirality Measures for Vectors, Matrices, Operators and Functions
Authors: Dryzun Chaim , Avnir David 
Published: December 2010

AbstractWe introduce the general form of the continuous chirality measure (CCM), which is a quantitative estimation of the degree of chirality for a given object. The generalization makes it possible to calculate the chirality content of any mathematical description of a system by vectors, matrices, operators and functions. Another advantage of the new methodology is the ability to provide analytical expressions for the chirality measures. We apply it for specific cases, including vectors and molecules (amino acids), rotation matrices (metamaterials design), rotational potential operators (representing, for example, parity violation), and functions (the electronic structure of annulenes).
Thermomorphic Behavior of the Ionic Liquids [C4mim][FeCl4] and [C12mim][FeCl4]
Authors: Xie Zai‐Lai , Taubert Andreas 
Published: December 2010

AbstractThe iron‐containing ionic liquids 1‐butyl‐3‐methylimidazolium tetrachloroferrate(III) [C4mim][FeCl4] and 1‐dodecyl‐3‐methylimidazolium tetrachloroferrate(III) [C12mim][FeCl4] exhibit a thermally induced demixing with water (thermomorphism). The phase separation temperature varies with IL weight fraction in water and can be tuned between 100 °C and room temperature. The reversible lower critical solution temperature (LCST) is only observed at IL weight fractions below ca. 35 % in water. UV/Vis, IR, and Raman spectroscopy along with elemental analysis prove that the yellow‐brown liquid phase recovered after phase separation is the starting IL [C4mim][FeCl4] and [C12mim][FeCl4], respectively. Photometry and ICP‐OES show that about 40 % of iron remains in the water phase upon phase separation. Although the process is thus not very efficient at the moment, the current approach is the first example of an LCST behavior of a metal‐containing IL and therefore, although still inefficient, a prototype for catalyst removal or metal extraction.
HomoFRET Fluorescence Anisotropy Imaging as a Tool to Study Molecular Self‐Assembly in Live Cells
Authors: Chan Fiona T. S. , Kaminski Clemens F. , Kaminski Schierle Gabriele S. 
Published: December 2010

AbstractMolecular self‐assembly is a defining feature of numerous biological functions and dysfunctions, ranging from basic cell signalling to diseases mediated by protein aggregation. There is current demand for novel experimental methods to study molecular self‐assembly in live cells, and thereby in its physiological context. Förster resonance energy transfer (FRET) between fluorophores of a single type, known as homoFRET, permits noninvasive detection and quantification of molecular clusters in live cells. It can thus provide powerful insights into the molecular physiology of living systems and disease. HomoFRET is detected by measuring the loss of fluorescence anisotropy upon excitation with polarised light. This article reviews recent key developments in homoFRET fluorescence anisotropy imaging for the detection and quantification of molecular self‐assembly reactions in biological systems. A summary is given of the current state‐of‐the‐art and case studies are presented of successful implementations, highlighting technical aspects which have to be mastered to bridge the gap between proof‐of‐concept experiments and biological discoveries.
Observation of Runaway Electron Behaviour During Disruptions in LHCD Discharges in the HT‐7 Tokamak
Authors: Lu H. W. , Hu L. Q. , Li S. Y. , Zhou R. J. , Zhong G. Q. , the HT‐7 Team  
Published: December 2010

AbstractProduction of runaway electrons during disruptions has been observed in the HT‐7 Tokamak. The runaway current plateaus, which can carry part of the pre‐disruptive current, are observed in lower‐hybrid current drive (LHCD) limiter discharges. It is found that the runaway current can mitigate the disruptions effectively. We can use gas puffing to increase the line‐averaged density to restrain the runaway electrons and rebuild the plasmas after the disruptions. Detailed observations are presented on the runaway electrons generated following disruptions in the HT‐7 tokamak discharges. The results indicate that the magnetic oscillations play a significant role in the loss of runaway electrons in disruptions. There are two important preconditions to rebuild plasmas by runaway electrons after the disruptions. One of them are weak magnetic oscillations; another one are LHWs (lower‐hybrid waves) (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear Behavior of Electromagnetic Waves in Ultra‐Relativistic Electron‐Positron Plasmas
Authors: Liu Y. , Liu S. Q. 
Published: December 2010

AbstractA set of nonlinear equations which can self‐consistently describe the behavior of high frequency Electromagnetic (EM) waves in un‐magnetized, ultra‐relativistic electron‐positron (e‐p) plasmas is obtained on the basis of Vlasov‐Maxwell equations. Nonlinear wave‐wave, wave‐particle interactions lead to the coupling of high frequency EM waves with low frequency density perturbations which result from EM waves radiation pressure. The same as that in conventional electron‐ion (e‐i) plasmas, strong EM waves in e‐p plasmas will give rise to density depletion in which itself are trapped. But on the contrary to that in e‐i plasmas, there no longer exists electrostatic acoustic–like wave in e‐p plasmas due to the absence of mass difference. For linear polarized EM waves, a stationary EM soliton with a spiky structure will be formed. The possible relation of the localized field to pulsar radio pulse is discussed (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Effect of a Poloidal Phase Difference on the Asymmetry of the Coupling Characteristics of an ICRH Antenna
Authors: Du Dan , Gong Xue‐Yu , Hu He‐Ping , Liu Bai‐Qing , Huang Qian‐Hong , Lu Xing‐Qiang 
Published: December 2010

AbstractThe coupling asymmetry characteristics of an ion cyclotron resonance heating (ICRH) antenna consisting of two poloidal aligned straps are studied for a JET‐type tokamak. The model used combines a three‐dimensional (3‐D) planar, cold‐plasma, single pass antenna‐plasma coupling code with any phase difference between the current straps, which takes into account the feeders' current and phase difference effects. The result shows that the asymmetry of radiated energy in poloidal direction can be controlled through changing the phase difference of the antenna straps, and when the phase difference equals to π, the asymmetry tends to become most pronounced (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effective Polytropic Indices of Anisotropic Planetary Magnetosheath Plasmas with Magnetoacoustic Waves
Authors: Meister C.‐V. , Maurer Ch. , Hoffmann D.H.H. 
Published: December 2010

AbstractMagnetosheath models for the planets Earth, Jupiter and Saturn are developed within the frame of the double‐adiabatic Chew‐Goldberger‐Low approximation. It is shown that in all three magnetosheaths slow and fast magnetoacoustic waves are generated, the dispersions of which considerably differ from that of isotropic systems. If slow magnetoacoustic waves exist in the magnetosheaths, then the effective polytropic coefficient of the plasma may be smaller than unity ‐ that means compression of the plasma is accompanied, in the average, by cooling. Such polytropic coefficients are not obtained when fast magnetoacoustic waves are excited (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Local Field Corrections Effect on Equation of State in Dense Hydrogen Plasma: Plasma Phase Transition
Authors: Bennadji K. 
Published: December 2010

AbstractWe present calculations of Hydrogen plasma pressure including local field correction (LFC) effects modelled in the Singwi Tosi Land and Sjölander model extended to arbitrary temperature (ATSTLS), neutrals contributions are not included. We show that LFC induces thermodynamic instabilities (phase transition) in the vicinity of the maximum electron coupling parameter which corresponds to maximum departure of the ATSTLS electron polarizability from the Random Phase Approximation one. Comparison of our results to Monte‐Carlo calculations induced us to think that free electron coupling plays a dominant role in plasma phase transition. Critical temperature is estimated and compared to existing values (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron Temperature Dependence of the Dissociative Recombination Coefficient of Molecular Argon Ions Ar+2 with Electrons
Authors: Lukáč P. , Mikuš O. , Morva I. , Zábudlá Z. , Trnovec J. , Morvová M. 
Published: December 2010

AbstractA dual mode (TM010 cylindrical cavity/cylindrical waveguide) microwave apparatus is used to study the ion mobility and dissociative recombination of molecular argon ions with electrons in the afterglow period of a d.c. glow discharge as a function of electron temperature when electrons were heated by microwaves up to Te ≤ 10300K, with T+ = Tgas = 300K. The electron temperature dependence of the total rate coefficient of dissociative recombination may be represented by α (Ar+2) = (8.1 ± 0.5) × 10–7[300/Te(inK)]0.64cm3s–1 which is in very good agreement with most previous experimental results but not with the recent theoretical calculations (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The Quantum Excess Free Energy for Two Component Plasma
Authors: Hussein N. A. , Ibrahim D. A. E. 
Published: December 2010

AbstractThe aim of this paper is to calculate the quantum excess free energy until the third virial coefficient for the two component plasma (TCP). We consider only the thermal equilibrium plasma in the case of nλ3ab ≪ 1 where λ2ab = (ħ2/(mabKT)) is the thermal De Broglie wave‐length. The second and third virial coefficients are represented in forms of a convergent series expansion in terms of the interaction Parameter ξ2ab = ((eaeb)/(λabKT)). We obtained the excess free energy until the third virial coefficient to the order ξ6ab. The effects of symmetry are taken into account, also the exchange effects were taken in account. We compared our results with others. Upon comparison with Ebeling et al. one observes that the considerable contribution of the third virial coefficient in the region of high temperatures (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Environmental enrichment influences neuronal stem cells in the adult crayfish brain
Authors: Ayub Neishay , Benton Jeanne L. , Zhang Yi , Beltz Barbara S. 
Published: December 2010

AbstractNew neurons are incorporated throughout life into the brains of many vertebrate and nonvertebrate species. This process of adult neurogenesis is regulated by a variety of external and endogenous factors, including environmental enrichment, which increases the production of neurons in juvenile mice and crayfish. The primary goal of this study was to exploit the spatial separation of the neuronal precursor cell lineage in crayfish to determine which generation(s) of precursors is altered by environmental conditions. Further, in crayfish, an intimate relationship between the first‐generation neuronal precursors (stem cells) and cells circulating in the hemolymph has been proposed (Zhang et al., 2009). Therefore, a second goal was to assess whether environmental enrichment alters the numbers or types of cells circulating in the hemolymph. We find that neurogenesis in the brains of sexually differentiated procambarid crayfish is enhanced by environmental enrichment as previously demonstrated by Sandeman and Sandeman (2000) in young, sexually undifferentiated Cherax destructor. We also show that environmental enrichment increases the cell cycle rate of neuronal stem cells. Although there was no effect of environment on the overall numbers of cells circulating in the hemolymph, enrichment resulted in increased expression of glutamine synthetase (GS), a marker of the neuronal stem cells, in a small percentage of circulating cells; there was little or no GS immunoreactivity in hemolymph cells extracted from deprived animals. Thus, environmental enrichment influences the rate of neuronal stem cell division in adult crayfish, as well as the composition of cells circulating in the hemolymph. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 71: 351–361, 2011
Neurongrowth, a software for automatic quantification of neurite and filopodial dynamics from time‐lapse sequences of digital images
Authors: Fanti Zian , Elena Martinez‐Perez M. , De‐Miguel Francisco F. 
Published: December 2010

AbstractWe developed NeuronGrowth, a software for the automatic quantification of extension and retraction of neurites and filopodia, from time‐lapse sequences of two‐dimensional digital micrographs. NeuronGrowth requires a semiautomatic characterization of individual neurites in a reference frame, which is then used for automatic tracking and measurement of every neurite over the whole image sequence. Modules for sequence alignment, background subtraction, flat field correction, light normalization, and cropping have been integrated to improve the quality of the analysis. Moreover, NeuronGrowth incorporates a deconvolution filter that corrects the shadow‐cast effect of differential interference contrast (DIC) images. NeuronGrowth was tested by analyzing the formation of outgrowth patterns by individual leech neurons cultured under two different conditions. Phase contrast images were obtained from neurons plated on CNS homogenates and DIC images were obtained from similar neurons plated on ganglion capsules as substrates. Filopodia were measured from fluorescent growth‐cones of chick dorsal root ganglion cells. Quantitative data of neurite extension and retraction obtained by three different users applying NeuronGrowth and two other manually operated software packages were similar. However, NeuronGrowth required less user participation and had a better time performance when compared with the other software packages. NeuronGrowth may be used in general to quantify the dynamics of tubular structures such as blood vessels. NeuronGrowth is a free plug‐in for the free software ImageJ and can be downloaded along with a user manual, a troubleshooting section and other information required for its use from http://www.ifc.unam.mx or http://www.ifc.unam.mx/ffm/index.html. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 71: 870–881, 2011
Par proteins and neuronal polarity
Authors: Insolera Ryan , Chen She , Shi Song‐Hai 
Published: December 2010

AbstractA hallmark of neurons is their ability to polarize with dendrite and axon specification to allow the proper flow of information through the nervous system. Over the past decade, extensive research has been performed in an attempt to understand the molecular and cellular machinery mediating this neuronal polarization process. It has become evident that many of the critical regulators involved in establishing neuronal polarity are evolutionarily conserved proteins that had previously been implicated in controlling the polarization of other cell types. At the forefront of this research are the partition defective (Par) proteins. In this review,we will provide a commentary on the progressof work regarding the central importance of Parproteins in the establishment of neuronal polarity. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 71: 483–494, 2011
Enteric neurons synthesize netrins and are essential for the development of the vagal sensory innervation of the fetal gut
Authors: Ratcliffe Elyanne M. , Fan Lena , Mohammed Tandi J. , Anderson Monique , Chalazonitis Alcmène , Gershon Michael D. 
Published: December 2010

AbstractDuring fetal life, vagal sensory fibers establish a reproducible distribution in the gut that includes an association with myenteric ganglia. Previous work has shown that netrin is expressed in the bowel wall and, by acting on its receptor, deleted in colorectal cancer (DCC), mediates the guidance of vagal sensory axons to the developing gut. Because the highest concentration of netrins in fetal bowel is in the endoderm, we tested the hypothesis that the ingrowth of vagal afferents to the gut would be independent of the presence of enteric neurons, although enteric neurons might influence the internal distribution of these fibers. Surprisingly, experiments indicated that the vagal sensory innervation is intrinsic neuron‐dependent. To examine the vagal innervation in the absence of enteric ganglia, fetal Ret −/− mice were labeled by applying DiI bilaterally to nodose ganglia. In Ret −/− mice, DiI‐labeled vagal sensory axons descended in paraesophageal trunks as far as the proximal stomach, which contains neurons, but did not enter the aganglionic bowel. To determine whether neurons produce netrins, enteric neural‐crest‐derived cells (ENCDCs) were immunoselected from E15 rat gut. Transcripts encoding netrin‐1 and ‐3 were not detected in the ENCDCs, but appeared after they had given rise to neurons. When these neurons were cocultured with cells expressing c‐Myc‐tagged netrin‐1, the neurons displayed netrin‐1, but not c‐Myc, immunoreactivity. Enteric neurons thus synthesize netrins. The extent to which neuronal netrin accounts for the dependence of the vagal sensory innervation on intrinsic neurons, remains to be determined. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 71: 362–373, 2011
Kinetic spectrophotometric methods for the determination of artificial sweetener (sucralose) in tablets
Authors: Youssef Rasha M. , Korany Mohamed A. , Khamis Essam F. , Mahgoub Hoda , Kamal Miranda F. 
Published: December 2010

AbstractTwo simple and sensitive kinetic spectrophotometric methods for the determination of sucralose are described. The first method is based upon a kinetic investigation of the oxidation reaction of the drug with alkaline potassium permanganate at room temperature for a fixed time of 30 min. The absorbance of the green coloured manganate ions produced was measured at 610 nm. The second method is based on the reaction of sucralose with cerium (IV) ammonium sulfate in the presence of perchloric acid with the subsequent measurement of the excess unreacted cerium (IV) ammonium sulfate at 320 nm at a fixed time of 30 min in a thermostated water bath at 60 ± 1 °C. This principle is adopted to develop a kinetic method for sucralose determination. The absorbance concentration plots in both methods were rectilinear over the range 4–16 and 10–30 µg ml−1, for the first and second methods, respectively. The different experimental parameters affecting the development and stability of the colours were carefully studied and optimized. The determination of sucralose by rate constant method, fixed concentration method, and fixed‐time method was also feasible with calibration equations obtained but the latter method was found to be more applicable. The two methods have been applied successfully to commercial tablets. Copyright © 2010 John Wiley & Sons, Ltd.