bluuebunny/crossref_metadata_2025 huggingface dataset:
Language and Brain – Facts, Problems, Mysteries
Authors: Bierwisch Manfred
Published: November 2008

The representation of language in the brain is one of the lively topics in recent cognitive neurosciences. The present paper argues that standard models of structures and mechanisms of the brain, which are essentially based on principles of activation spreading in neuronal nets and learning by synaptic strengthening through coincidental activation, cannot account for crucial properties of the Language Faculty and are misguided in central respects. In particular, the apparently elegant notion that working memory is just the activated state of long-term memory is shown to be incapable of accounting for structures and processes of language production and comprehension. Four types of problems are sketched that illustrate the impasses encountered by standard models of activation spreading.
How Does Early Brain Organization Promote Language Acquisition in Humans?
Authors: Dehaene-Lambertz G. , Hertz-Pannier L. , Dubois J. , Dehaene S.
Published: November 2008

Speech processing in adults relies on precise and specialized networks, located primarily in the left hemisphere. Behavioural studies in infants indicate that a considerable amount of language learning already takes place in the first year of life in the domains of phonology, prosody, and word segmentation. Thanks to the progress of neuro-imaging, we can move beyond behavioural methods and examine how the infant’s brain processes verbal stimuli before learning. These studies reveal a structural and functional organization close to what is described in adults and suggest a strong bias for speech processing in these regions that might guide infants in the discovery of the properties of their native language, although no evidence can be provided as yet for speech specificity of such networks.
Antimicrobial resistance in companion animals
Authors: Scott Weese J.
Published: November 2008

Antimicrobial resistance (AMR) is an emerging problem in companion animals, because of difficult-to-treat infections, possible pressure to use antimicrobials that are important in human medicine, and potential zoonotic transmission. The extent and importance of AMR in companion animals are poorly understood, in part because of limited surveillance; however, it is clear that resistance is problematic in many pathogens and commensals, including staphylococci, enterococci,Escherichia coliandSalmonella.
Antimicrobial peptides and bacteriocins: alternatives to traditional antibiotics
Authors: Sang Yongming , Blecha Frank
Published: November 2008

Antimicrobial peptides (AMPs) are ubiquitous, gene-encoded natural antibiotics that have gained recent attention in the search for new antimicrobials to combat infectious disease. In multicellular organisms, AMPs, such as defensins and cathelicidins, provide a coordinated protective response against infection and are a principal component of innate immunity in vertebrates. In unicellular organisms, AMPs, such as bacteriocins, function to suppress competitor species. Because many AMPs kill bacteria by disruption of membrane integrity and are thus thought to be less likely to induce resistance, AMPs are being extensively evaluated as novel antimicrobial drugs. This review summarizes and discusses the antibiotic properties of AMPs highlighting their potential as alternatives to conventional antibiotics.
Dietary modulation of the mucosal immune response to a parasite
Authors: McClure Susan J
Published: November 2008

This study investigated the hypothesis that dietary deficiency of readily available carbohydrate (raCHO) modifies the immune response of lambs to the gastrointestinal nematode Trichostrongylus colubriformis. Sixty helminthologically naive Merino lambs were fed throughout the experiment diets containing three levels of raCHO that provided adequate, moderate or low intakes according to recommended standards and were given primary or both primary and secondary infections of T. colubriformis. A further 20 uninfected lambs received the low diet for 9 weeks, after which they were returned to the standard diet. Immune status was assessed by the measurement of plasma and jejunal antibody concentrations and blood and jejunal cell numbers and function. Diets low in carbohydrate resulted in a failure of the lambs to gain weight and decreases in plasma glucose concentration, blood lymphocytes expressing CD8 or Tcrγδ, monocytes, eosinophils, platelets and red blood cells, jejunal and plasma antibody concentrations, lymphocyte proliferation to worm antigen and numbers of jejunal CD8+ and Tcrδγ+ lymphocytes, eosinophils and CD1b+ dendritic cells. Thus, a low dietary concentration of raCHOs impaired the constitutive availability of lymphocytes and antigen‐presenting cells, and the cellular and humoral immunological responses. A hypothesis is suggested for the mechanism and for the possible wider implications.
Noninvasive and Quantitative Assessment of the Function of Multidrug Resistance-Associated Protein 1 in the Living Brain
Authors: Okamura Toshimitsu , Kikuchi Tatsuya , Okada Maki , Toramatsu Chie , Fukushi Kiyoshi , Takei Makoto , Irie Toshiaki
Published: November 2008

Multidrug resistance-associated protein 1 (MRP1) acts as a defense mechanism by pumping xenobiotics and endogenous metabolites out of the brain. The currently available techniques for studying brain-to-blood efflux have significant limitations related to either their invasiveness or the qualitative assessment. Here, we describe an in vivo method, which overcomes these limitations for assessing MRP1 function, using positron emission tomography (PET) and a PET probe. 6-Bromo-7-[11C]methylpurine was designed to readily enter the brain after intravenous administration and to be efficiently converted to its glutathione conjugate (MRP1 substrate) in situ. Dynamic PET scan provided the brain time—activity curve after injection of 6-bromo-7-[11C]methylpurine into mice. The efflux rate of the substrate was kinetically estimated to be 1.4 h−1with high precision. Moreover, knockout of Mrp1 gene caused approximately a 90% reduction of the efflux rate, compared with wild-type mice. In conclusion, our method allows noninvasive and quantitative assessment for MRP1 function in the living brain.
Expression and purification of human vascular‐endothelial‐growth‐factor‐receptor‐2 tyrosine kinase in Streptomyces for inhibitor screening
Authors: Liu Chunping , Guo Lianhong , Yao Chen , Zhang Ren , Li Yuan
Published: November 2008

VEGF (vascular endothelial growth factor) is a critical regulator in angiogenesis through binding to its specific receptors, including VEGFR‐2 (VEGF receptor 2), a kinase insert domain‐containing receptor, on the surface of endothelial cells. As angiogenesis has been shown to be essential for malignancy of tumours, VEGFR‐2 is a potential therapeutic target for the treatment of cancers. To explore this potential, VEGFR‐2‐CD (the protein tyrosine kinase catalytic domain of VEGFR‐2) was cloned and expressed in Streptomyces lividans TK24, a prokaryotic expression system. The recombinant protein was purified, and correlations between its activity and enzyme concentration, ATP concentration, substrate concentration and bivalent cations were characterized. An ELISA‐based screening system was then established and used to search for inhibitors acting on the tyrosine kinase part of VEGFR‐2. More than 600 compounds originating from a variety of microbes have been screened so far, and a number of them have been demonstrated to be potential inhibitors of VEGFR‐2 TK.
A purification method for improving the process yield and quality of recombinant human granulocyte colony‐stimulating factor expressed in Escherichia coli and its characterization
Authors: Rao Dasari Venkata Krishna , Narasu Mangamoori Lakshmi , Rao Adibhatla Kali Satya Bhujanga
Published: November 2008

A purification method employing a process‐control strategy was developed for improving the yield of rhG‐CSF (recombinant human granulocyte colony‐stimulating factor). A purity of ≥99% with an overall yield of 2.18 g/l was achieved in the present study. Analysis of the product during purification indicated that detergents removed 72% of LPS (lipopolysaccharides) and 98% of HCPs (host cell proteins) without removing nucleic acid. Cysteine concentration was a key parameter in protein refolding. The bed height and HETP (height equivalent theoretical plates) value in the SEC (size‐exclusion chromatography) column was evaluated and its impact on the resolution was studied. Formulation during SEC was found to be crucial for increasing the product yields with saving of time and process costs. The yield obtained in the present study is nearly four times higher than that reported in the literature. The product obtained was found to be acceptable for toxicological studies.
Rab11 regulates the recycling of the β2-adrenergic receptor through a direct interaction
Authors: Parent Audrey , Hamelin Emilie , Germain Pascale , Parent Jean-Luc
Published: November 2008

The β2ARs (β2-adrenergic receptors) undergo ligand-induced internalization into early endosomes, but then are rapidly and efficiently recycled back to the plasma membrane, restoring the numbers of functional cell-surface receptors. Gathering evidence suggests that, during prolonged exposure to agonist, some β2ARs also utilize a slow recycling pathway through the perinuclear recycling endosomal compartment regulated by the small GTPase Rab11. In the present study, we demonstrate by co-immunoprecipitation studies that there is a β2AR–Rab11 association in HEK-293 cells (human embryonic kidney cells). We show using purified His6-tagged Rab11 protein and β2AR intracellular domains fused to GST (glutathione transferase) that Rab11 interacts directly with the C-terminal tail of β2AR, but not with the other intracellular domains of the receptor. Pull-down and immunoprecipitation assays revealed that the β2AR interacts preferentially with the GDP-bound form of Rab11. Arg333 and Lys348 in the C-terminal tail of the β2AR were identified as crucial determinants for Rab11 binding. A β2AR construct with these two residues mutated to alanine, β2AR RK/AA (R333A/K348A), was generated. Analysis of cell-surface receptors by ELISA revealed that the recycling of β2AR RK/AA was drastically reduced when compared with wild-type β2AR after agonist washout, following prolonged receptor stimulation. Confocal microscopy demonstrated that the β2AR RK/AA mutant failed to co-localize with Rab11 and recycle to the plasma membrane, in contrast with the wild-type receptor. To our knowledge, the present study is the first report of a direct interaction between the β2AR and a Rab GTPase, which is required for the accurate intracellular trafficking of the receptor.
Oxysterol activation of phosphatidylcholine synthesis involves CTP:phosphocholine cytidylyltransferase α translocation to the nuclear envelope
Authors: Gehrig Karsten , Lagace Thomas A. , Ridgway Neale D.
Published: November 2008

In addition to suppressing cholesterol synthesis and uptake, oxysterols also activate glycerophospholipid and SM (sphingomyelin) synthesis, possibly to buffer cells from excess sterol accumulation. In the present study, we investigated the effects of oxysterols on the CDP-choline pathway for PtdCho (phosphatidylcholine) synthesis using wild-type and sterol-resistant CHO (Chinese-hamster ovary) cells expressing a mutant of SCAP [SREBP (sterol-regulatory-element-binding protein) cleavage-activating protein] (CHO-SCAP D443N). [3H]Choline-labelling experiments showed that 25OH (25-hydroxycholesterol), 22OH (22-hydroxycholesterol) and 27OH (27-hydroxycholesterol) increased PtdCho synthesis in CHO cells as a result of CCTα (CTP:phosphocholine cytidylyltransferase α) translocation and activation at the NE (nuclear envelope). These oxysterols also activate PtdCho synthesis in J774 macrophages. in vitro, CCTα activity was stimulated 2- to 2.5-fold by liposomes containing 5 mol% 25OH, 22OH or 27OH. Inclusion of up to 5 mol% cholesterol did not further activate CCTα. 25OH activated CCTα in CHO-SCAP D443N cells leading to a transient increase in PtdCho synthesis and accumulation of CDP-choline. CCTα translocation to the NE and intranuclear tubules in CHO-SCAP D443N cells was complete after 1 h exposure to 25OH compared with only partial translocation by 4–6 h in CHO-Mock cells. These enhanced responses in CHO-D443N cells were sterol-dependent since depletion with cyclodextrin or lovastatin resulted in reduced sensitivity to 25OH. However, the lack of effect of cholesterol on in vitro CCT activity indicates an indirect relationship or involvement of other sterols or oxysterol. We conclude that translocation and activation of CCTα at nuclear membranes by side-chain hydroxylated sterols are regulated by the cholesterol status of the cell.
Turkish Stuttering Association: A Model Project to Bring Stuttering Self-help to Turkey
Authors: Louis Kenneth O. St. , Topbaş Seyhun , OÖzdemir R. Sertan
Published: November 2008

A new self-help organization has been established to serve stuttering individuals and their families and/or friends in Turkey and other Turkish-speaking areas of the world. This Turkish Stuttering Association (TKB for “Türkiye Kekemelik Birliği” in Turkish) was inaugurated with a Web site in both Turkish and English. The Web site permits discussions among those who stutter and other interested persons. The next step is to foster face-to-face chapters of the TKB through the Web site and via annual workshops at the Education, Research, and Training Center for Speech and Language Disorders (DILKOM) at Anadolu University in Eskisehir, Turkey.
High-efficiency, low-voltage phosphorescent organic light-emitting diode devices with mixed host
Authors: Kondakova Marina E. , Pawlik Thomas D. , Young Ralph H. , Giesen David J. , Kondakov Denis Y. , Brown Christopher T. , Deaton Joseph C. , Lenhard Jerome R. , Klubek Kevin P.
Published: November 2008

We report high-efficiency, low-voltage phosphorescent green and blue organic light-emitting diode (PHOLED) devices using mixed-host materials in the light-emitting layer (LEL) and various combinations of electron-injecting and electron-transporting layers. The low voltage does not rely on doping of the charge-transport layers. The mixed LEL architecture offers significantly improved efficiency and voltage compared to conventional PHOLEDs with neat hosts, in part by loosening the connection between the electrical band gap and the triplet energy. Bulk recombination in the LEL occurs within ∼10 nm of the interface with an electron-blocking layer. A “hole-blocking layer” need not have hole- or triplet-exciton-blocking properties. Optical microcavity effects on the spectrum and efficiency were used to locate the recombination zone. The effect of layer thickness on drive voltage was used to determine the voltage budget of a typical device. The behavior of undoped devices was investigated, and the electroluminescence is attributed to an exciplex of the two host materials. Electrically detected electron paramagnetic resonance was used to study the behavior of doped and undoped PHOLED devices from 20 to 200 K, which largely mimics the behavior of the same devices at room temperature.
High temperature thermoelectric characteristics of Ca0.9R0.1MnO3 (R=La,Pr,…,Yb)
Authors: Wang Yang , Sui Yu , Su Wenhui
Published: November 2008

Electron-doped perovskite manganite Ca0.9R0.1MnO3 (R=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb) polycrystalline samples were prepared and their transport and thermoelectric properties were studied from room temperature to 1000 K. The transport behavior for all the samples is adiabatic small polaron hopping mechanism below 600 K but changes to metallic conductivity at higher temperature. Above 600 K, more 3d electrons of Mn3+ ions will occupy eg orbitals, resulting in the variation in thermoelectric power values. For all the samples, thermoelectric power is only determined by carrier concentration, but resistivity also rests with effective bandwidth. The size matching between Ca2+ and R3+ ions together with heavier R3+ doping can improve thermoelectric performance evidently. Combining these two factors, Ca0.9Dy0.1MnO3 and Ca0.9Yb0.1MnO3 reach ZT=0.2 at 1000 K, suggesting that they can be efficient high temperature n-type thermoelectric oxide materials.
On the spectral theory and dispersive estimates for a discrete Schrödinger equation in one dimension
Authors: Pelinovsky D. E. , Stefanov A.
Published: November 2008

Based on the recent work [Komech et al., “Dispersive estimates for 1D discrete Schrödinger and Klein-Gordon equations,” Appl. Anal. 85, 1487 (2006)] for compact potentials, we develop the spectral theory for the one-dimensional discrete Schrödinger operator, Hϕ=(−Δ+V)ϕ=−(ϕn+1+ϕn−1−2ϕn)+Vnϕn. We show that under appropriate decay conditions on the general potential (and a nonresonance condition at the spectral edges), the spectrum of H consists of finitely many eigenvalues of finite multiplicities and the essential (absolutely continuous) spectrum, while the resolvent satisfies the limiting absorption principle and the Puiseux expansions near the edges. These properties imply the dispersive estimates ‖eitHPa.c.(H)‖lσ2→l−σ2≲t−3/2 for any fixed σ>52 and any t>0, where Pa.c.(H) denotes the spectral projection to the absolutely continuous spectrum of H. In addition, based on the scattering theory for the discrete Jost solutions and the previous results by Stefanov and Kevrekidis [“Asymptotic behaviour of small solutions for the discrete nonlinear Schrödinger and Klein-Gordon equations,” Nonlinearity 18, 1841 (2005)], we find new dispersive estimates ‖eitHPa.c.(H)‖l1→l∞≲t−1/3, which are sharp for the discrete Schrödinger operators even for V=0.
NMR and Seebeck coefficient studies of the electronic band structure in Nb1−xB2
Authors: Su T. H. , Lue C. S. , Kuo Y. K.
Published: November 2008

With the aim of providing experimental information for the Nb deficiency enhanced superconducting temperature (TC) in the Nb1−xB2 samples, we carried out a study on Nb1−xB2 (x=0, 0.13, 0.20, and 0.26) by means of nuclear magnetic resonance (NMR) and Seebeck coefficient (S) measurements. From the N93b NMR spin-lattice relaxation rates, we can deduce the Nb 4d partial Fermi level density of states (DOS) Nd(EF) for each individual composition. The result indicates that Nb0.74B2 and Nb0.80B2 possess large Nd(EF) while the lowest one appears in Nb0.87B2. The Seebeck coefficient also shows smaller absolute values in Nb0.74B2 and Nb0.80B2, associated with higher Fermi level DOS in both compounds. Interestingly, the temperature variation in S exhibits a broad minimum in Nb0.87B2, which is attributed to the presence of a pseudogap near the Fermi level. These observations were found to be in good agreement with the prediction from band structure calculations based on the appearance of the Nb vacancies in Nb1−xB2. In addition, the present study clearly reveals that the observed Tc enhancement by Nb deficiency has no direct relevance to their electronic Fermi level DOS.
Highly textured SmCo5 (001) thin film with high coercivity
Authors: Chen J. S. , Zhang L. N. , Hu J. F. , Ding J.
Published: November 2008

The seedlayer effect on crystallographic structure and magnetic properties of cosputtered SmCo films on Cu underlayer was investigated. Highly textured (001) SmCo5 thin films were obtained by introducing a thin Ti or Ta seedlayer. Especially, with the Ta seedlayer, the half maximum of the rocking curve of SmCo (001) peak was as small as 3.4° and the high-index SmCo5 (003) diffraction peak was clearly observed, showing a high quality of texture and crystallinity. The SmCo5 films showed a large perpendicular anisotropy with out-of-plane coercivities over 20 kOe. Well crystallized SmCo5 films with (001) texture could be obtained at a temperature as low as 325 °C. The crystallinity, (001) texture, and magnetic properties of SmCo5 thin films were found to be dependent on deposition temperature, the texture of the Cu (111) underlayer, roughness of the Cu underlayer, and formation of SmCoCu alloy through the Cu diffusion.
Fatigue measurement system designed for a chalcogenide-based device using a homemade heater tip
Authors: Kim H. J. , Choi S. K. , Kang S. H. , Oh K. H.
Published: November 2008

A fatigue measurement system is designed using a homemade tungsten (W) heater tip. This system is composed of a pulse generator and an atomic force microscope with the W heater tip attached. Also included are a parameter analyzer and control devices. The entire measurement process is controlled by a designed program without communication errors. Additionally, a process to fabricate the sharp W heater tip that applies an electrical pulse and evaluates the electrical properties is introduced. The analysis of the tip, carried out by scanning electron microscopy and electron backscattering diffraction, shows that the tip has great thermomechanical stability. Using this fatigue measurement system, the resistance of the Ge2Sb2Te5 (GST) cell was successfully measured as a function of the number of set/reset cycles. The specific area (both program area and failure area) was easily observed. It is expected that the expansion of GST is a source of information regarding the fatigue of a GST cell.
Terahertz vibrational absorption spectroscopy using microstrip-line waveguides
Authors: Byrne M. B. , Cunningham J. , Tych K. , Burnett A. D. , Stringer M. R. , Wood C. D. , Dazhang L. , Lachab M. , Linfield E. H. , Davies A. G.
Published: November 2008

We demonstrate that terahertz microstrip-line waveguides can be used to measure absorption spectra of polycrystalline materials with a high frequency resolution (∼2 GHz) and with a spatial resolution that is determined by the microstrip-line dimensions, rather than the free-space wavelength. The evanescent terahertz-bandwidth electric field extending above the microstrip line interacts with, and is modified by, overlaid dielectric samples, thus enabling the characteristic vibrational absorption resonances in the sample to be probed. As an example, the terahertz absorption spectrum of polycrystalline lactose monohydrate was investigated; the lowest lying mode was observed at 534(±2) GHz, in excellent agreement with free-space measurements. This microstrip technique offers both a higher spatial and frequency resolution than free-space terahertz time-domain spectroscopy and requires no contact between the waveguide and sample.
Electrowetting-enhanced microfluidic device for drop generation
Authors: Gu Hao , Malloggi Florent , Vanapalli Siva A. , Mugele Frieder
Published: November 2008

We integrated electrowetting into a microfluidic flow focusing device to study drop generation under the influence of electric fields. Using both the dispersed phase inlet pressure and the applied voltage as control parameters, we find that the range of drop sizes and the drop generation rate can be controlled in a much finer way than with hydrodynamics alone. In particular a “conical spray” regime occurring at a voltage of O(50 V) allows for continuous tuning of the (highly monodisperse) drop diameter from ≈5 to 50 μm at a fixed continuous flow rate.
Growth of atomically smooth MgO films on graphene by molecular beam epitaxy
Authors: Wang W. H. , Han W. , Pi K. , McCreary K. M. , Miao F. , Bao W. , Lau C. N. , Kawakami R. K.
Published: November 2008

We investigate the growth of MgO films on graphene by molecular beam epitaxy and find that surface diffusion promotes a rough morphology. To reduce the mobility of surface atoms, the graphene surface is dressed by Ti atoms prior to MgO deposition. With as little as 0.5 ML (monolayer) of Ti, the MgO overlayer becomes atomically smooth. Furthermore, no aggregation of MgO is observed at the edges of the graphene sheet. These results are important for the fabrication of nanoscale electronic and spintronic devices.
BaTiO
3
-carbon nanotube/polyvinylidene fluoride three-phase composites with high dielectric constant and low dielectric loss
Authors: Yao Sheng-Hong , Dang Zhi-Min , Jiang Mei-Juan , Bai JinBo
Published: November 2008

A three-phase composite with multiwall carbon nanotube (MWNT) and BaTiO3 particles embedded into polyvinylidene fluoride (PVDF) was prepared. The uniform dispersion of fillers was realized, and the dielectric constant was as high as 151 at 102Hz when the volume fraction of MWNT and BaTiO3 were 0.01 and 0.15, respectively. The BaTiO3-MWNT/PVDF composite with high dielectric constant displayed relatively low dielectric loss and good flexibility due to the low concentrations of MWNT and BaTiO3. The results can be explained by the space charge polarization at the interfaces between the conductor and the insulator and the evolutions of conductive pathway and microcapacitance structure.
Quantitative dopant profiling of laser annealed focused ion beam-prepared silicon p-n junctions with nanometer-scale resolution
Authors: Cooper David , Hartmann Jean-Michel , Aventurier Bernard , Templier Francois , Chabli Amal
Published: November 2008

Silicon p-n junction specimens have been prepared by focused ion beam milling for examination using off-axis electron holography. By using 28nS pulsed XeCl excimer laser irradiation we have reduced the total electrically “inactive” thickness in these specimens from 142to5nm. A platinum layer has been sputtered onto the specimen surfaces to remove the build up of charge from the region of interest during examination. Subsequently, a value of the built in potential has been determined directly from a phase image which is consistent with theory.
High fidelity optical readout of excited-state lifetimes and ionization of hydrogenic donors in GaAs
Authors: Allen D. G. , Kim Sangwoo , Stanley C. R. , Sherwin M. S.
Published: November 2008

Optical detection of terahertz-frequency Rydberg transitions of neutral donors in GaAs is demonstrated via state-dependent resonance fluorescence from the neutral donor bound exciton (DX0) transition. The intensity of the elastically scattered light is proportional to the fraction of donor-bound electrons in the (bright) ground state; excited state and ionized donors are dark. Resonance fluorescence recovery after terahertz excitation yields a single-shot, time-resolved measurement of the lifetime of the lowest excited (2P−) state. We also demonstrate contactless detection of electron ionization/capture via the ionized donor exciton (DX+) transition.
Living tissue under treatment of cold plasma atmospheric jet
Authors: Shashurin A. , Keidar M. , Bronnikov S. , Jurjus R. A. , Stepp M. A.
Published: November 2008

The interaction of the cold atmospheric plasma jet with fibroblast cells was studied. Plasma jet was initiated in the helium flow blowing through the syringe by application of high ac voltage to the discharge electrodes. The plasma jet had a length of 5cm and a diameter of 1.5–2mm in ambient air. Treatment of cells with plasma jet resulted in decreasing of cell migration rate, cell detachment, and appearance of “frozen” cells, while treatment with helium flow (no plasma) resulted in appearance of frozen cells only. A variety of cellular responses was explained by different intensities of treatment.
Fabrication of negative index materials using dielectric and metallic composite route
Authors: Ma Y. G. , Zhao L. , Wang P. , Ong C. K.
Published: November 2008

In this work the authors proposed a dielectric and metallic composite route to design a negative index material. It was shown that a high-permittivity dielectric geometry could excite a magnetic dipolar resonance mode. Its incorporation with metallic wire resonators would generate the double negative resonance behavior, which gave the negative index. The homogenization ability of extending the composite combination into three dimensional structures was discussed.
Surface and bulk contribution to Cu(111) quantum efficiency
Authors: Pedersoli E. , Greaves C. M. R. , Wan W. , Coleman-Smith C. , Padmore H. A. , Pagliara S. , Cartella A. , Lamarca F. , Ferrini G. , Galimberti G. , Montagnese M. , dal Conte S. , Parmigiani F.
Published: November 2008

The quantum efficiency (QE) of Cu(111) is measured for different impinging light angles with photon energies just above the work function. We observe that the vectorial photoelectric effect, an enhancement of the QE due to illumination with light with an electric vector perpendicular to the sample surface, is stronger in the more surface sensitive regime. This can be explained by a contribution to photoemission due to the variation in the electromagnetic potential at the surface. The contributions of bulk and surface electrons can then be determined.
Žižek's Dialectics of Difference and the Problem of Space
Authors: Secor Anna J
Published: November 2008

This paper begins with the question of what about dialectics might be interesting to geographers today. I argue that, for those who are interested in engaging dialectical thought, Slavoj Žižek's work offers a productive way of conceptualizing an open dialectic without synthesis or totality. The goal of this paper is to explain Žižek' idea of the parallax view and to demonstrate its relevance for geographers. To do this, I begin by showing how Žižek's dialectical vision differs from that of David Harvey by using the example of Harvey's analysis of ‘capitalist imperialism’. Next, I turn to Deleuzian spatial ontology and its understandings of virtual and actual spaces. I discuss Žižek's engagement with Gilles Deleuze's thought and draw out the implications of a dialectical understanding of the virtual and the actual.
The Subaltern Moment in Hegel's Dialectic
Authors: Gidwani Vinay
Published: November 2008

I stage the question ‘What about dialectics?’ by showing Frantz Fanon's insurrectionary fidelity to Georg Wilhelm Friedrich Hegel and his dialectic. Fanon is an acute and disloyal reader of Hegel, and relentlessly probes the moment of negation in Hegel's dialectic to pry it open for an emancipatory, nonsublative politics of a ‘new humanity’. Fanon's attempts to side with the radical implications of otherness disclose the ‘subaltern moment’ in Hegel's dialectic and leave us a de formed Hegel, profoundly equivocal and no longer easily named (hence, recognized) as the philosopher of synthesis and reconciliation.
Dialegesthai: Towards a Posttranscendent Politics—Or, let's Talk about Bodies
Authors: Hooper Barbara
Published: November 2008

The purpose of this essay is neither to praise or condemn dialectic nor to adjudicate between dialectics. I seek instead to investigate a particular relation between dialectic and dualism that was developed in the ancient Greek polis as a way of opening a conversation concerning the necessity of waging a posttranscendent, postdualist politics. Approaching the polis through the problematic nomos of flesh, and focusing on the produced opposition between reason and appetite, the essay suggests how a dispositif of transcendence operated in the polis to reduce the rule of the many, associated with the mob-like appetites of the body, in favor of the few who had (allegedly) achieved self-mastery and transcendence. For beings produced as body this meant a greater degree of corporeal vulnerability and a reduced, at times radically reduced, potential for survival. This politics of transcendence did not vanish with the polis but persisted in diverse forms, continuing to under-write the unevenly distributed right to be that it originally authorized and that, beginning in ‘1492’, was globalized, becoming the massive assault on bodies that has characterized the bio(geo)politics of Western modernity and still dominates the present. The essay concludes with a consideration of what a posttranscendent politics might be and a postscript regarding the cunning of passion.
Dialectics Revisited. Reality Discharged
Authors: Doel Marcus A
Published: November 2008

Dialectics is a powerful way of engaging with our conflicted world, and yet it remains obscure, neglected, and badly misunderstood. Despite the prevalence of attempts to come to terms with all manner of antagonisms, contradictions, polarities, and oppositions across a host of theoretical practices and domains, relatively few authors make recourse to dialectics, and those who do invariably frame it within the following, rather unhelpful, terms: thesis–antithesis–synthesis or position–negation–negation-of-the-negation. While the advent of poststructuralism in general, and of deconstruction in particular, has arguably robbed the dialectic of much of its purchase, it is nonetheless worth revisiting dialectics since it offers an exemplary distillation of what is at stake in thinking through the Real as conflicted and charged. Accordingly, the paper is an attempt to clarify the dialectical articulation of the Real in its confliction, and advances the heretical possibility that the Real may be bereft of charge. Almost everyone works on the basis of a charged Reality—of a Real that is essentially polarized, antagonized, and conflicted—and most critical and fatal theorists dream of discharging the Real: selectively in the case of the former; wholesale in the case of the latter. Thinking through dialectics in the company of deconstruction and poststructuralism, however, opens up an entirely new terrain for the Real that is untouched by the positive and the negative, and which slips through the grasp of both critical and fatal theory. Reality is always already cracked open, but there is nothing to discharge.
Changing Times, Changing Places: Urban Development and the Politics of Space–Time
Authors: Raco Mike , Henderson Steven , Bowlby Sophie
Published: November 2008

Much of the writing on urban regeneration in the UK has been focused on the types of urban spaces that have been created in city centres. Less has been written about the issue of when the benefits of regeneration could and should be delivered to a range of different interests, and the different time frames that exist in any development area. Different perceptions of time have been reflected in dominant development philosophies in the UK and elsewhere. The trickle-down agendas of the 1980s, for example, were criticised for their focus on the short-term time frames and needs of developers, often at the expense of those of local communities. The recent emergence of sustainability discourses, however, ostensibly changes the time focus of development and promotes a broader concern with new imagined futures. This paper draws on the example of development in Salford Quays, in the North West of England, to argue that more attention needs to be given to the politics of space–time in urban development processes. It begins by discussing the importance and relevance of this approach before turning to the case study and the ways in which the local politics of space–time has influenced development agendas and outcomes. The paper argues that such an approach harbours the potential for more progressive, far-reaching, and sustainable development agendas to be developed and implemented.
Formation and Stabilization of Anisotropic Palladium and Platinum Nanoparticles in Aqueous Polymer Solution Using Microwave Irradiation
Authors: Pal Angshuman , Shah Sunil , Chakraborty Debjani , Devi Surekha
Published: November 2008

Anisotropic palladium and platinum nanoparticles were synthesized by reduction of the corresponding metal ions with hydrazine using polyacrylamide as a stabilizing agent in aqueous medium under microwave irradiation. The formation of particles was confirmed by UV-visible spectroscopy. The size and shape of the particles were determined using transmission electron microscopy. Rapid microwave heating resulted in ‘star-shaped’ palladium nanoparticles, but platinum nanoparticles were observed to be spherical with a distinctly visible 3–4 nm coating of polyacrylamide on their surface, which was not observed for the palladium particles. The Pt nanoparticles were used as a catalyst in the redox reaction.
An Efficacious Protocol for the Oxidation of 3,4-Dihydropyrimidin-2(1H)-ones using Pyridinium Chlorochromate as Catalyst
Authors: Singh Kamaljit , Singh Kawaljit
Published: November 2008

4-Unsubstituted as well as 4,6-aryl/alkyl-3,4-dihydropyrimidin-2(1H)-ones were oxidized under neutral conditions using pyridinium chlorochromate to obtain the corresponding pyrimidin-2(1H)-ones in a synthetically useful manner.
Two Interesting One-Dimensional Chainlike Architectures Formed by Substituted Keggin Polyoxoanions and Novel Cobalt - Ethylenediamine Complexes
Authors: Wang Yu , Zhang Zhiming , Wang Enbo , Qi Yanfei , Chang Song
Published: November 2008

Two novel supported heteropolytungstates, NaH3[CoIII(en)2(OH)SiW11CoIIO39]·9.25H2O 1 (en = ethylenediamine) and [Co(en)2]4[Co4(Hen)2Si2W18O68]·H2en·6H2O 2 have been synthesized and characterized by single-crystal X-ray diffraction, electrochemistry, IR, and thermogravimetry. Compound 1 exhibits an interesting one-dimensional chainlike architecture assembled by bridged sodium ions that support monosubstituted Keggin polyoxoanions. To our knowledge, it represents the first example of a supported structure that consists of monosubstituted Keggin polyoxoanions and a novel interbridged, dinuclear Co metal unit. Compound 2 is constructed from trivacant Keggin polyanions linked through a tetrameric cobalt unit, which coordinates with organonitrogen ligands. Moreover, the sandwich-type polyoxoanions were connected by two [Co(en)2] coordination complexes, respectively, and linked by Co2+ ions into a straight chain.
Synthesis of 2-Aryl- and 2,5-Diarylfurans and Thiophenes by Suzuki - Miyaura Reactions Using Potassium Trifluoroborate Salts and Heteroaryltellurides
Authors: Botteselle Giancarlo V. , Hough Thomas L. S. , Venturoso Raphael C. , Cella Rodrigo , Vieira Adriano S. , Stefani Helio A.
Published: November 2008

The Suzuki–Miyaura cross-coupling reaction of 2-(butyltellanyl) or 2,5-bis-(butyltellanyl)furans and thiophenes with potassium aryltrifluoroborate salts catalyzed by palladium afforded 2-aryl- or 2,5-diaryl-furans and thiophenes in moderate to good yields.
Ruthenium(II) Complexes of New Chelating Indolizino[2,3-b]pyrazine- and Indolizino[2,3-b]quinoxaline-Derived Ligands: Syntheses, Electrochemistry and Absorption Spectroscopy
Authors: Sumby Christopher J.
Published: November 2008

The highly conjugated chelating ligands 5-(2-pyridyl)indolizino[2,3-b]pyrazine 1, 5-(2-pyridyl)indolizino[2,3-b]quinoxaline 2, and 8,9-dimethyl-5-(2-pyridyl)indolizino[2,3-b]quinoxaline 3 were prepared in one step, with good yields, from di-2-pyridylmethane and 2,3-dichloropyrazine, 2,3-dichloroquinoxaline, and 8,9-dimethyl-2,3-dichloroquinoxaline, respectively. Compounds 1–3 display long-wavelength absorption maxima in the green (1) and yellow (2 and 3) to give intensely coloured red and purple solutions, respectively. Bis(2,2′-bipyridyl)ruthenium(ii) and bis(4,4′-dimethyl-2,2′-bipyridyl)ruthenium(ii) complexes were prepared in moderate to good yields, characterized by NMR spectroscopy and mass spectrometry, and studied by cyclic voltammetry and absorption spectroscopy. Copper(ii) and silver(i) nitrate complexes of the ligands were prepared and complexes [Cu(NO3)2(1)], [Cu(NO3)2(2)]2, and [Ag(NO3)(3)2] were characterized by X-ray crystallography. These structures revealed the planar nature of the ligands and confirmed the proposed chelating mode.
A Design to Improve Internal Validity of Assessments of Teaching Demonstrations
Authors: Bartsch Robert A. , Bittner Wendy M. Engelhardt , Moreno Jesse E.
Published: November 2008

Internal validity is important in assessing teaching demonstrations both for one's knowledge and for quality assessment demanded by outside sources. We describe a method to improve the internal validity of assessments of teaching demonstrations: a 1-group pretest–posttest design with alternative forms. This design is often more practical and ethical than random assignment, and it is more valid than a single posttest-only or simple 1-group pretest–posttest design. We describe how to interpret results from this design and discuss the advantages and disadvantages.
Improving Learning through Interventions of Student-Generated Questions and Concept Maps
Authors: Berry Jack W. , Chew Stephen L.
Published: November 2008

Using the principles of the scholarship of teaching and learning, we evaluated 2 learning strategies to determine if they could improve student exam performance in general psychology. After the second of 3 exams, we gave students the option of participating in a specific learning activity and assessed its impact using the third exam. In Study 1, participating students generated a minimum of 3 questions per week over course material. Lower performing students who participated improved their exam performance such that they were indistinguishable from stronger students who did not participate. In Study 2, students had the option of generating concept maps over course material. Generating concept maps significantly improved performance.
Models and Exemplars of Scholarship in the Teaching of Psychology
Authors: Buskist William , Carlson Janet F. , Christopher Andrew N. , Prieto Loreto , Smith Randolph A.
Published: November 2008

This article provides ideas for engaging in the scholarship of teaching in psychology. Topics covered include contributing to the Society for the Teaching of Psychology's Office of Teaching Resources in Psychology and Teaching of Psychology. Writing and editing books also constitute scholarly work. Finally, teaching with intentionality and accountability can be productive in leading to scholarship opportunities. By providing models and exemplars of scholarship in the teaching of psychology, we hope to encourage more teachers to engage in such activities.
Assessing Effective Teaching of Psychology: A Meta-Analytic Integration of Learning Outcomes
Authors: Tomcho Thomas J. , Foels Rob
Published: November 2008

Teaching researchers can assess learning outcome effectiveness as a function of students' graded performance or changes in knowledge, skills and behaviors, or attitudes. We meta-analyzed 197 studies to determine the effectiveness of teaching activities in Teaching of Psychology (ToP) both overall and also as a function of type of learning outcome assessment. We found that, on average, studies evidenced a medium effect size across types of learning outcomes. Given the effectiveness of ToP teaching activities, researchers should address the (a) potential confounding role of teacher rapport, immediacy, and alliance in evaluating teaching effectiveness; (b) ethics of teaching activity development; and (c) appropriateness of using course grades to assess teaching activity effectiveness.
Integrating Teacher Behaviors with Character Strengths and Virtues for Faculty Development
Authors: McGovern Thomas V. , Miller Samantha Leigh
Published: November 2008

We describe a model for new and senior faculty members, integrating a behavioral approach to enhancing teaching skills with research from the field of positive psychology on virtues and character strengths. The Teacher Behaviors Checklist (Keeley, Smith, & Buskist, 2006) identifies target behaviors amenable to modification, derived from qualitative descriptors associated with teaching exemplars. The Values in Action Inventory of Strengths (Peterson, Park, & Seligman, 2005) is a self-assessment instrument that yields priority rankings on 24 character strengths and 6 trait-like virtues identified from multidisciplinary and multicultural literature. Used together, the feedback from both instruments offers well-researched stimuli for faculty to be more reflective and deliberate about their teaching and learning strategies.
Theoretical study of the dihydrogen bonded HMH···HB≡NH and HMH···HN≡BH complexes (M=Be, Mg and Ca): properties and structures
Authors: Ghiasi Reza , Monajjemi Majid
Published: November 2008

The nature of HMH···HB≡NH and HMH···HN≡BH (M=Be, Mg and Ca) interactions were studied with ab initio calculations. The interaction energies were calculated at MP2/6–311++G(2d,2p) level. The calculations suggest that the size of cation and the interaction mode of HB≡NH are two influential factors that affect the nature of interaction. AIM and NBO analyses of complexes indicate that the variation of densities and the extent of charge transfers upon complexation correlate well with the obtained interaction energies. The character of interactions has been compared with the HMH···HC≡CH complexes.
Adoption of Alcohol-Based Handrub by United States Hospitals: A National Survey
Authors: Mody Lona , Saint Sanjay , Kaufman Samuel R. , Kowalski Christine , Krein Sarah L.
Published: November 2008

The extent to which the use of alcohol-based handrub for hand hygiene has been adopted by US hospitals is unknown. A survey of infection control coordinators (response rate, 516 [72%] of 719) revealed that most hospitals (436 [84%] of 516) have adopted alcohol-based handrub. Leadership support and staff receptivity play a significant role in its adoption.
Shortest path analysis using partial correlations for classifying gene functions from gene expression data
Authors: Fitch A. Marie , Jones M. Beatrix
Published: November 2008

Motivation: Gaussian graphical models (GGMs) are a popular tool for representing gene association structures. We propose using estimated partial correlations from these models to attach lengths to the edges of the GGM, where the length of an edge is inversely related to the partial correlation between the gene pair. Graphical lasso is used to fit the GGMs and obtain partial correlations. The shortest paths between pairs of genes are found. Where terminal genes have the same biological function intermediate genes on the path are classified as having the same function. We validate the method using genes of known function using the Rosetta Compendium of yeast (Saccharomyces Cerevisiae) gene expression profiles. We also compare our results with those obtained using a graph constructed using correlations.

Results: Using a partial correlation graph, we are able to classify approximately twice as many genes to the same level of accuracy as when using a correlation graph. More importantly when both methods are tuned to classify a similar number of genes, the partial correlation approach can increase the accuracy of the classifications.

Contact:  m.fitch@massey.ac.nz
A SNARE Complex Unique to Seed Plants Is Required for Protein Storage Vacuole Biogenesis and Seed Development ofArabidopsis thaliana
Authors: Ebine Kazuo , Okatani Yusuke , Uemura Tomohiro , Goh Tatsuaki , Shoda Keiko , Niihama Mitsuru , Morita Miyo Terao , Spitzer Christoph , Otegui Marisa S. , Nakano Akihiko , Ueda Takashi
Published: November 2008

The SNARE complex is a key regulator of vesicular traffic, executing membrane fusion between transport vesicles or organelles and target membranes. A functional SNARE complex consists of four coiled-coil helical bundles, three of which are supplied by Q-SNAREs and another from an R-SNARE. Arabidopsis thaliana VAMP727 is an R-SNARE, with homologs only in seed plants. We have found that VAMP727 colocalizes with SYP22/ VAM3, a Q-SNARE, on a subpopulation of prevacuolar compartments/endosomes closely associated with the vacuolar membrane. Genetic and biochemical analyses, including examination of a synergistic interaction of vamp727 and syp22 mutations, histological examination of protein localization, and coimmunoprecipitation from Arabidopsis lysates indicate that VAMP727 forms a complex with SYP22, VTI11, and SYP51 and that this complex plays a crucial role in vacuolar transport, seed maturation, and vacuole biogenesis. We suggest that the VAMP727 complex mediates the membrane fusion between the prevacuolar compartment and the vacuole and that this process has evolved as an essential step for seed development.