bluuebunny/crossref_metadata_2025 huggingface dataset:
Spelling and word recognition in Grades 1 and 2: Relations to phonological awareness and naming speed in Dutch children
Authors: VERHAGEN WIM G. M. , AARNOUTSE COR A. J. , VAN LEEUWE JAN F. J.
Published: December 2009

The influences of early phonological awareness and naming speed on Dutch children's later word spelling were investigated in a longitudinal study. Phonological awareness and naming speed predicted spelling in early Grade 1, later Grade 1, and later Grade 2. Phonological awareness, however, predominated over naming speed for the prediction of early Grade 1 spelling. Comparison of the present results with those from an earlier study of children's word recognition using the same dataset and also structural equation modeling showed word recognition speed at the ends of Grades 1 and 2 in the earlier study to be uniquely predicted by early naming speed. Nonetheless, naming speed may measure almost the same in word recognition and word spelling accuracy.
Young children's sensitivity to new and given information when answering predicate-focus questions
Authors: SALOMO DOROTHÉ , LIEVEN ELENA , TOMASELLO MICHAEL
Published: December 2009

In two studies we investigated 2-year-old children's answers to predicate-focus questions depending on the preceding context. Children were presented with a successive series of short video clips showing transitive actions (e.g., frog washing duck) in which either the action (action-new) or the patient (patient-new) was the changing, and therefore new, element. During the last scene the experimenter asked the question (e.g., “What's the frog doing now?”). We found that children expressed the action and the patient in the patient-new condition but expressed only the action in the action-new condition. These results show that children are sensitive to both the predicate-focus question and newness in context. A further finding was that children expressed new patients in their answers more often when there was a verbal context prior to the questions than when there was not.
Peanut consumption and cardiovascular risk
Authors: Ghadimi Nouran Mina , Kimiagar Masoud , Abadi Alireza , Mirzazadeh Majid , Harrison Gail
Published: December 2009

Objective

We evaluated the effects of peanut consumption on lipid profiles, atherogenic index of plasma (AIP) and CHD risk in hypercholesterolaemic men.

Design

Randomised crossover clinical trial.

Setting

Participants were randomly assigned to two groups. They were asked to consume peanut supplements (about 77 g) with their habitual diet for 4 weeks.

Subjects

Fifty-four hypercholesterolaemic men with total cholesterol (TC) concentrations between 200 and 350 mg/dl.

Results

Compared with the habitual diet, peanut supplementation of the habitual diet significantly reduced TC/HDL cholesterol (HDL-C) ratio (mean 1 (se 0·3) P = 0·001) and LDL cholesterol (LDL-C)/HDL-C ratio (mean 0·7 (se 0·2); P = 0·001). Peanut consumption increased HDL-C (mean 6·1 (se 1·5) mg/dl; P < 0·001) and total antioxidant capacity (TAC) (mean 1·2 (se 0·6) U/mL P = 0·04). In addition, peanut consumption significantly reduced the AIP (mean 0·1 (se 0·03) P = 0·01) and CHD estimated risk over 10 years based on systolic and diastolic blood pressures (mean 1·4 % (se 0·5 %) P = 0·004 and mean 2·2 % (se 0·5 %) P < 0·001, respectively).

Conclusions

Short-term peanut consumption might improve lipid profiles, the AIP and CHD risk in free-living hypercholesterolaemic men.
Kainate receptors and signal integration by NG2 glial cells
Authors: Kukley Maria , Dietrich Dirk
Published: December 2009

It is well established that NG2 cells throughout the young and adult brain consistently detect the release of single vesicles filled with glutamate from nearby axons. The released neurotransmitter glutamate electrically excites NG2 cells via non-NMDA (N-methyl-D-aspartic acid) glutamate receptors but the individual contribution of AMPA and kainate receptors to neuron-NG2 cell signalling, is not well understood. Here we pharmacologically block AMPA-type glutamate receptors and investigate whether hippocampal NG2 cells also express the kainate subtype of glutamate receptors and what may be their contribution to synaptic connectivity. It has been shown previously that vesicular glutamate release does not lead to a detectable activation of kainate receptors on NG2 cells. Here we report that while bath application of 250 nM–1 μM kainate does not have a major effect on NG2 cells it consistently induces a small and persistent depolarising current. This current was not mimicked by ATPA, suggesting that this current is carried by non-GluR5 containing kainate receptors. In addition to this inward current, nanomolar concentrations of kainate also produced a dramatic increase in the frequency of spontaneous GABA-A receptor-mediated synaptic currents (IPSCs) in NG2 cells. This increase in spontaneous IPSC frequency was even more pronounced on application of the GluR5-specific agonist ATPA (approximately 15-fold increase in frequency). In contrast, mono-synaptic stimulated IPSCs recorded in NG2 cells were unaffected by kainate receptor activation. Those and further experiments show that the occurrence of the high frequency of IPSCs is due to action potential firing of hippocampal interneurons caused by activation of GluR5 receptors on the somatodendritic membrane of the interneurons. Our data suggest that hippocampal kainate receptors are not only important for communication between neurons but may also play a dual and subtype-specific role for neuron–glia signalling: Firstly, extra-synaptic non-GluR5 kainate receptors in the membrane of NG2 cells are ideally suited to instruct NG2 cells on the population activity of local excitatory neurons via ambient glutamate. Secondly, based on the known importance of GluR5 receptors on hippocampal interneurons for the generation of network rhythms and based on our finding that these interneurons heavily project onto NG2 cells, it appears that synaptic activation of interneuronal GluR5 receptors triggers signalling to NG2 cells which transmits the phase and frequency of ongoing network oscillations in the developing hippocampus.
The role of glial cells in influencing neurite extension by dorsal root ganglion cells
Authors: Ng Kai-Yu , Wong Yung H. , Wise Helen
Published: December 2009

When pretreated with pertussis toxin (PTX), the neurites of adult rat dorsal root ganglion (DRG) cells in mixed cell cultures retract over a period of 2 h following the initial stimulus of removal from the cell culture incubator for brief periods of observation. The purpose of this investigation was to determine whether this PTX-dependent response was specific to any one of the three subpopulations of DRG neurons. However, no neurite retraction response was observed in neuron-enriched populations of cells, or in cultures enriched in isolectin B4 (IB4)-positive neurons or in IB4-negative neurons. But, the addition of non-neuronal cells, and/or medium conditioned by non-neuronal cells, was sufficient to restore the PTX-dependent neurite retraction response, but only in large diameter IB4-negative neurons. In conclusion, we have identified a regulatory response, mediated by Gi/o-proteins, which prevents retraction of neurites in large diameter IB4-negative cells of adult rat DRG. The non-neuronal cells of adult rat DRG constitutively release factor/s that can stimulate neurite retraction of a subset of isolated DRG neurons, but this property of non-neuronal cells is only observed when the Gi/o-proteins of large diameter IB4-negative cells are inhibited.
Grounding line movement and ice shelf buttressing in marine ice sheets
Authors: Goldberg D. , Holland D. M. , Schoof C.
Published: December 2009

Understanding the dynamics of marine ice sheets is integral to studying the evolution of the Antarctic ice sheet in both the short and long terms. An important component of the dynamics, grounding line migration, has proved difficult to represent in numerical models, and most successful attempts have made use of techniques that are only readily applicable to flow line models. However, to capture the stress transmission involved in another important component, the buttressing of a marine ice sheet by its ice shelf, the transverse direction must also be resolved. We introduce a model that solves the time‐dependent shelfy stream equations and makes use of mesh adaption techniques to overcome the difficulties typically associated with the numerics of grounding line migration. We compare the model output with a recent benchmark for flow line models and show that our model yields an accurate solution while using far less resources than would be required without mesh adaption. We also show that the mesh adapting techniques extend to two horizontal dimensions. Experiments are carried out to determine how both ice shelf buttressing and ice rises affect the marine instability predicted for an ice sheet on a foredeepened bed. We find that buttressing is not always sufficient to stabilize such a sheet but collapse of the grounded portion is still greatly delayed. We also find that the effect of an ice rise is similar to that of narrowing the ice shelf.
Time domain analysis of thin‐wire antennas over lossy ground using the reflection‐coefficient approximation
Authors: Fernández Pantoja M. , Yarovoy A. G. , Rubio Bretones A. , González García S.
Published: December 2009

This paper presents a procedure to extend the methods of moments in time domain for the transient analysis of thin‐wire antennas to include those cases where the antennas are located over a lossy half‐space. This extended technique is based on the reflection coefficient (RC) approach, which approximates the fields incident on the ground interface as plane waves and calculates the time domain RC using the inverse Fourier transform of Fresnel equations. The implementation presented in this paper uses general expressions for the RC which extend its range of applicability to lossy grounds, and is proven to be accurate and fast for antennas located not too near to the ground. The resulting general purpose procedure, able to treat arbitrarily oriented thin‐wire antennas, is appropriate for all kind of half‐spaces, including lossy cases, and it has turned out to be as computationally fast solving the problem of an arbitrary ground as dealing with a perfect electric conductor ground plane. Results show a numerical validation of the method for different half‐spaces, paying special attention to the influence of the antenna to ground distance in the accuracy of the results.
Shimmed matching pulses: Simultaneous control of rf and static gradients for inhomogeneity correction
Authors: Franck John M. , Demas Vasiliki , Martin Rachel W. , Bouchard Louis-S. , Pines Alexander
Published: December 2009

Portable NMR systems generally suffer from poor field homogeneity and are therefore used more commonly for imaging and relaxation measurements rather than for spectroscopy. In recent years, various approaches have been proposed to increase the sample volume that is usable for spectroscopy. These include approaches based on manual shimming and those based on clever combinations of modulated radio frequency and gradient fields. However, this volume remains small and, therefore, of limited utility. We present improved pulses designed to correct for inhomogeneous dispersion across wide ranges of frequency offsets without eliminating chemical shift or spatial encoding. This method, based on the adiabatic double passage, combines the relatively larger corrections available from spatially matched rf gradients [C. Meriles et al., J. Magn. Reson. 164, 177 (2003)]. with the adjustable corrections available from time-modulated static field gradients [D. Topgaard et al., Proc. Natl. Acad. Sci. U.S.A. 101, 17576 (2004)]. We explain the origins of these corrections with a theoretical model that simplifies and expedites the design of the pulse waveforms. We also present a generalized method for evaluating and comparing pulses designed for inhomogeneity correction. Experiments validate this method and support simulations that offer new possibilities for significantly enhanced performance in portable environments.
Quadratic exponential vectors
Authors: Accardi Luigi , Dhahri Ameur
Published: December 2009

We give a necessary and sufficient condition for the existence of a quadratic exponential vector with test function in L2(Rd)∩L∞(Rd). We prove the linear independence and totality, in the quadratic Fock space, of these vectors. Using a technique different from the one used by Accardi et al. [Quantum Probability and Infinite Dimensional Analysis, Vol. 25, p. 262, (2009)], we also extend, to a more general class of test functions, the explicit form of the scalar product between two such vectors.
Lie symmetries and exact solutions of the barotropic vorticity equation
Authors: Bihlo Alexander , Popovych Roman O.
Published: December 2009

Lie group methods are used for the study of various issues related to symmetries and exact solutions of the barotropic vorticity equation. The Lie symmetries of the barotropic vorticity equations on the f- and β-planes, as well as on the sphere in rotating and rest reference frames, are determined. A symmetry background for reducing the rotating reference frame to the rest frame is presented. The one- and two-dimensional inequivalent subalgebras of the Lie invariance algebras of both equations are exhaustively classified and then used to compute invariant solutions of the vorticity equations. This provides large classes of exact solutions, which include both Rossby and Rossby–Haurwitz waves as special cases. We also discuss the possibility of partial invariance for the β-plane equation, thereby further extending the family of its exact solutions. This is done in a more systematic and complete way than previously available in literature.
Effect of Zr concentration on conductivity behavior of (1−x)PMN-xPZ ceramic: An impedance spectroscopy analysis
Authors: Singh Gurvinderjit , Tiwari V. S.
Published: December 2009

Impedance spectroscopy study was carried out on Pb[Mg(1−x)/3Nb2(1−x)/3Zrx]O3 for x=0.10, 0.20, and 0.30 in the frequency range 100 Hz–1 MHz and temperature range 498–723 K. The activation energies obtained for the conduction increase with an increase in Zr4+ content. A significant decrease in the electrical conductivity was observed by an increase in Zr4+ substitution. The conduction mechanism in PMN-PZ is attributed to the migration of doubly ionized oxygen vacancies. These results are explained in terms of lowering the structural disorder in PMN by Zr4+ substitution.
Competing nucleation pathways in a mixture of oppositely charged colloids: Out-of-equilibrium nucleation revisited
Authors: Peters Baron
Published: December 2009

Recent simulations of crystal nucleation from a compressed liquid of oppositely charged colloids show that the natural Brownian dynamics results in nuclei of a charge-disordered FCC (DFCC) solid whereas artificially accelerated dynamics with charge swap moves result in charge-ordered nuclei of a CsCl phase. These results were interpreted as a breakdown of the quasiequilibrium assumption for precritical nuclei. We use structure-specific nucleus size coordinates for the CsCl and DFCC structures and equilibrium based sampling methods to understand the dynamical effects on structure selectivity in this system. Nonequilibrium effects observed in previous simulations emerge from a diffusion tensor that dramatically changes when charge swap moves are used. Without the charge swap moves diffusion is strongly anisotropic with very slow motion along the charge-ordered CsCl axis and faster motion along the DFCC axis. Kramers–Langer–Berezhkovskii–Szabo theory predicts that under the realistic dynamics, the diffusion anisotropy shifts the current toward the DFCC axis. The diffusion tensor also varies with location on the free energy landscape. A numerical calculation of the current field with a diffusion tensor that depends on the location in the free energy landscape exacerbates the extent to which the current is skewed toward DFCC structures. Our analysis confirms that quasiequilibrium theories based on equilibrium properties can explain the nonequilibrium behavior of this system. Our analysis also shows that using a structure-specific nucleus size coordinate for each possible nucleation product can provide mechanistic insight on selectivity and competition between nucleation pathways.
Silver nanowire array-polymer composite as thermal interface material
Authors: Xu Ju , Munari Alessio , Dalton Eric , Mathewson Alan , Razeeb Kafil M.
Published: December 2009

Silver nanowire arrays embedded inside polycarbonate templates are investigated as a viable thermal interface material for electronic cooling applications. The composite shows an average thermal diffusivity value of 1.89×10−5 m2 s−1, which resulted in an intrinsic thermal conductivity of 30.3 W m−1 K−1. The nanowires’ protrusion from the film surface enables it to conform to the surface roughness to make a better thermal contact. This resulted in a 61% reduction in thermal impedance when compared with blank polymer. An ∼30 nm Au film on the top of the composite was found to act as a heat spreader, reducing the thermal impedance further by 35%. A contact impedance model was employed to compare the contact impedance of aligned silver nanowire-polymer composites with that of aligned carbon nanotubes, which showed that the Young’s modulus of the composite is the defining factor in the overall thermal impedance of these composites.
The dynamics of highly excited electronic systems: Applications of the electron force field
Authors: Su Julius T. , Goddard William A.
Published: December 2009

Highly excited heterogeneous complex materials are essential elements of important processes, ranging from inertial confinement fusion to semiconductor device fabrication. Understanding the dynamics of these systems has been challenging because of the difficulty in extracting mechanistic information from either experiment or theory. We describe here the electron force field (eFF) approximation to quantum mechanics which provides a practical approach to simulating the dynamics of such systems. eFF includes all the normal electrostatic interactions between electrons and nuclei and the normal quantum mechanical description of kinetic energy for the electrons, but contains two severe approximations: first, the individual electrons are represented as floating Gaussian wave packets whose position and size respond instantaneously to various forces during the dynamics; and second, these wave packets are combined into a many-body wave function as a Hartree product without explicit antisymmetrization. The Pauli principle is accounted for by adding an extra spin-dependent term to the Hamiltonian. These approximations are a logical extension of existing approaches to simulate the dynamics of fermions, which we review. In this paper, we discuss the details of the equations of motion and potentials that form eFF, and evaluate the ability of eFF to describe ground-state systems containing covalent, ionic, multicenter, and/or metallic bonds. We also summarize two eFF calculations previously reported on electronically excited systems: (1) the thermodynamics of hydrogen compressed up to ten times liquid density and heated up to 200 000 K; and (2) the dynamics of Auger fragmentation in a diamond nanoparticle, where hundreds of electron volts of excitation energy are dissipated over tens of femtoseconds. These cases represent the first steps toward using eFF to model highly excited electronic processes in complex materials.
Reversible assembly of magnetized particles: Application to water-borne pathogen enumeration
Authors: Ramadan Qasem
Published: December 2009

Reversible assembly of magnetized particles and cells has been proposed and implemented. The approach is based on magnetized particles or magnetically labeled cell immobilization in an array of individual particle/cell for optical counting. The device has been tested for few types of magnetic particles and one water-borne pathogen: Giardia Lamblia. An individual particle immobilization efficiency of 92% was achieved.
Polarization-induced switching effect in graphene nanoribbon edge-defect junction
Authors: Yin G. , Liang Y. Y. , Jiang F. , Chen H. , Wang P. , Note R. , Mizuseki H. , Kawazoe Y.
Published: December 2009

With nonequilibrium Green’s function approach combined with density functional theory, we perform an ab initio calculation to investigate transport properties of graphene nanoribbon (GNR) junctions self-consistently. Tight-binding approximation is applied to model the zigzag (ZGNR) electrodes, and its validity is confirmed in comparison to the GAUSSIAN03 periodic boundary condition calculation result of the same system. The origin of abnormal jump points usually appearing in the transmission spectrum is explained with the detailed tight-binding ZGNR band structure. Transport property of an edge-defect ZGNR junction is investigated, and the tunable tunneling current can be sensitively controlled by transverse electric fields.
An energy dispersive x-ray scattering and molecular dynamics study of liquid dimethyl carbonate
Authors: Gontrani Lorenzo , Russina Olga , Marincola Flaminia Cesare , Caminiti Ruggero
Published: December 2009

In this work, we report on the first x-ray diffraction study on liquid dimethyl carbonate. Diffraction spectra were collected with an energy-dispersive instrument, whose wide Q-range allows the structure determination of weakly ordered systems (such as liquids). The structural correlation in this liquid ranges up to about 20 Å. The observed patterns are interpreted with a structural model derived from classical molecular dynamics simulations. The simulations were run using OPLS force field, only slightly modified to restrain bond distances to the experimental values. The model structure function and radial distribution functions, averaged among the productive trajectory frames, are in very good agreement with the corresponding experimental ones. Molecular dynamics results show that the deviations from C2v cis-cis structure, predicted by ab initio calculations and observed by electron diffraction in the gas phase, are small. By analyzing the intra- and intermolecular pair distribution functions, it was possible to assign the peaks of the experimental radial distribution function to specific structural correlations, and to compute the different average intermolecular coordination numbers. The intermolecular methyl-carbonyl oxygen distance is thoroughly discussed to assess the presence of weak C–H⋯⋅O hydrogen bonds.
Correlation energy of two electrons in the high-density limit
Authors: Loos Pierre-François , Gill Peter M. W.
Published: December 2009

We consider the high-density-limit correlation energy Ec in D≥2 dimensions for the S1 ground states of three two-electron systems: helium (in which the electrons move in a Coulombic field), spherium (in which they move on the surface of a sphere), and hookium (in which they move in a quadratic potential). We find that the Ec values are strikingly similar, depending strongly on D but only weakly on the external potential. We conjecture that for large D, the limiting correlation energy Ec∼−δ2/8 in any confining external potential, where δ=1/(D−1).
Photoinduced change of dielectric permittivity in molecular doped polymer layer
Authors: Sakai Heisuke , Murata Hideyuki , Murakami Motonobu , Ohkubo Kei , Fukuzumi Shunichi
Published: December 2009

We demonstrate a large photoinduced change of dielectric permittivity due to the charge separated (CS) state of an electron donor-acceptor linked molecule, 6-[4′-(N,N-diphenylamino)phenyl]-3-ethoxycarbonylcoumarin (DPA–CM), doped in a polymethylmethacryrate (PMMA) matrix. Dielectric permittivity of DPA–CM in PMMA film increases from 4.1 to 7.5 under photoirradiation. Electron spin resonance spectra of the films measured under photoirradiation clearly show the formation of the CS state of DPA–CM in PMMA matrix. The origin of the photoinduced change of the dielectric permittivity is ascribed to the realignment of dipole of the CS state of DPA–CM.
Amorphous hafnium-indium-zinc oxide semiconductor thin film transistors
Authors: Kim Chang-Jung , Kim Sangwook , Lee Je-Hun , Park Jin-Seong , Kim Sunil , Park Jaechul , Lee Eunha , Lee Jaechul , Park Youngsoo , Kim Joo Han , Shin Sung Tae , Chung U-In
Published: December 2009

We developed amorphous hafnium-indium-zinc oxide (HIZO) thin films as oxide semiconductors and investigated the films electrically and physically. Adding of hafnium (Hf) element can suppress growing the columnar structure and drastically decrease the carrier concentration and hall mobility in HIZO films. The thin film transistors (TFTs) with amorphous HIZO active channel exhibit good electrical properties with field effect mobility of around 10 cm2/Vs, S of 0.23 V/decade, and high Ion/off ratio of over 108, enough to operate the next electronic devices. In particular, under bias-temperature stress test, the HIZO TFTs with 0.3 mol % (Hf content) showed only 0.46 V shift in threshold voltage, compared with 3.25 V shift in HIZO TFT (0.1 mol %). The Hf ions may play a key role to improve the instability of TFTs due to high oxygen bonding ability. Therefore, the amorphous HIZO semiconductor will be a prominent candidate as an operation device for large area electronic applications.
Thermophoretically driven carbon nanotube oscillators
Authors: Coluci V. R. , Timóteo V. S. , Galvão D. S.
Published: December 2009

The behavior of a nanodevice based upon double-walled carbon nanotube oscillators driven by periodically applied thermal gradients (7 and 17 K/nm) is investigated by numerical calculations and classical molecular dynamics simulations. Our results indicate that thermophoresis can be effective to initiate the oscillator and that suitable heat pulses may provide an appropriate way to tune its behavior. Sustained regular oscillatory as well as chaotic motions were observed for the systems investigated in this work.
High magnetic field matching effects in NbN films induced by template grown dense ferromagnetic nanowires arrays
Authors: Hallet X. , Mátéfi-Tempfli M. , Michotte S. , Piraux L. , Vanacken J. , Moshchalkov V. V. , Mátéfi-Tempfli S.
Published: December 2009

Dense arrays of ordered ferromagnetic nanowires have been used to create periodic magnetic pinning centers in thin superconducting NbN films. The nanowires were electrodeposited in a highly ordered porous alumina membrane and the thin NbN film was deposited on top of the perpendicularly oriented magnetic nanowires. Matching effects have been observed up to 2.5 T (11th matching field) and are maintained at low temperature. An appreciable enhancement of the superconducting properties is observed. At low fields, a hysteretic behavior in the magnetoresistance is found, directly related to the magnetization processes of arrays of interacting single domain ferromagnetic nanowires.
Actin remodeling by ADF/cofilin is required for cargo sorting at the trans-Golgi network
Authors: von Blume Julia , Duran Juan M. , Forlanelli Elena , Alleaume Anne-Marie , Egorov Mikhail , Polishchuk Roman , Molina Henrik , Malhotra Vivek
Published: December 2009

Knockdown of the actin-severing protein actin-depolymerizing factor (ADF)/cofilin inhibited export of an exogenously expressed soluble secretory protein from Golgi membranes in Drosophila melanogaster and mammalian tissue culture cells. A stable isotope labeling by amino acids in cell culture mass spectrometry–based protein profiling revealed that a large number of endogenous secretory proteins in mammalian cells were not secreted upon ADF/cofilin knockdown. Although many secretory proteins were retained, a Golgi-resident protein and a lysosomal hydrolase were aberrantly secreted upon ADF/cofilin knockdown. Overall, our findings indicate that inactivation of ADF/cofilin perturbed the sorting of a subset of both soluble and integral membrane proteins at the trans-Golgi network (TGN). We suggest that ADF/cofilin-dependent actin trimming generates a sorting domain at the TGN, which filters secretory cargo for export, and that uncontrolled growth of this domain causes missorting of proteins. This type of actin-dependent compartmentalization and filtering of secretory cargo at the TGN by ADF/cofilin could explain sorting of proteins that are destined to the cell surface.
Exaggerated inflammation, impaired host defense, and neuropathology in progranulin-deficient mice
Authors: Yin Fangfang , Banerjee Rebecca , Thomas Bobby , Zhou Ping , Qian Liping , Jia Ting , Ma Xiaojing , Ma Yao , Iadecola Costantino , Beal M. Flint , Nathan Carl , Ding Aihao
Published: December 2009

Progranulin (PGRN) is a widely expressed protein involved in diverse biological processes. Haploinsufficiency of PGRN in the human causes tau-negative, ubiquitin-positive frontotemporal dementia (FTD). However, the mechanisms are unknown. To explore the role of PGRN in vivo, we generated PGRN-deficient mice. Macrophages from these mice released less interleukin-10 and more inflammatory cytokines than wild type (WT) when exposed to bacterial lipopolysaccharide. PGRN-deficient mice failed to clear Listeria monocytogenes infection as quickly as WT and allowed bacteria to proliferate in the brain, with correspondingly greater inflammation than in WT. PGRN-deficient macrophages and microglia were cytotoxic to hippocampal cells in vitro, and PGRN-deficient hippocampal slices were hypersusceptible to deprivation of oxygen and glucose. With age, brains of PGRN-deficient mice displayed greater activation of microglia and astrocytes than WT, and their hippocampal and thalamic neurons accumulated cytosolic phosphorylated transactivation response element DNA binding protein–43. Thus, PGRN is a key regulator of inflammation and plays critical roles in both host defense and neuronal integrity. FTD associated with PGRN insufficiency may result from many years of reduced neutrotrophic support together with cumulative damage in association with dysregulated inflammation.
VSOP/Hv1 proton channels sustain calcium entry, neutrophil migration, and superoxide production by limiting cell depolarization and acidification
Authors: El Chemaly Antoun , Okochi Yoshifumi , Sasaki Mari , Arnaudeau Serge , Okamura Yasushi , Demaurex Nicolas
Published: December 2009

Neutrophils kill microbes with reactive oxygen species generated by the NADPH oxidase, an enzyme which moves electrons across membranes. Voltage-gated proton channels (voltage-sensing domain only protein [VSOP]/Hv1) are required for high-level superoxide production by phagocytes, but the mechanism of this effect is not established. We show that neutrophils from VSOP/Hv1−/− mice lack proton currents but have normal electron currents, indicating that these cells have a fully functional oxidase that cannot conduct protons. VSOP/Hv1−/− neutrophils had a more acidic cytosol, were more depolarized, and produced less superoxide and hydrogen peroxide than neutrophils from wild-type mice. Hydrogen peroxide production was rescued by providing an artificial conductance with gramicidin. Loss of VSOP/Hv1 also aborted calcium responses to chemoattractants, increased neutrophil spreading, and decreased neutrophil migration. The migration defect was restored by the addition of a calcium ionophore. Our findings indicate that proton channels extrude the acid and compensate the charge generated by the oxidase, thereby sustaining calcium entry signals that control the adhesion and motility of neutrophils. Loss of proton channels thus aborts superoxide production and causes a severe signaling defect in neutrophils.
Effects of drought on avian community structure
Authors: ALBRIGHT THOMAS P. , PIDGEON ANNA M. , RITTENHOUSE CHADWICK D. , CLAYTON MURRAY K. , FLATHER CURTIS H. , CULBERT PATRICK D. , WARDLOW BRIAN D. , RADELOFF VOLKER C.
Published: December 2009

Droughts are expected to become more frequent under global climate change. Avifauna depend on precipitation for hydration, cover, and food. While there are indications that avian communities respond negatively to drought, little is known about the response of birds with differing functional and behavioural traits, what time periods and indicators of drought are most relevant, or how response varies geographically at broad spatial scales. Our goals were thus to determine (1) how avian abundance and species richness are related to drought, (2) whether community variations are more related to vegetation vigour or precipitation deviations and at what time periods relationships were strongest, (3) how response varies among avian guilds, and (4) how response varies among ecoregions with different precipitation regimes. Using mixed effect models and 1989–2005 North American Breeding Bird Survey data over the central United States, we examined the response to 10 precipitation‐ and greenness‐based metrics by abundance and species richness of the avian community overall, and of four behavioural guilds. Drought was associated with the most negative impacts on avifauna in the semiarid Great Plains, while positive responses were observed in montane areas. Our models predict that in the plains, Neotropical migrants respond the most negatively to extreme drought, decreasing by 13.2% and 6.0% in abundance and richness, while permanent resident abundance and richness increase by 11.5% and 3.6%, respectively in montane areas. In most cases, response of abundance was greater than richness and models based on precipitation metrics spanning 32‐week time periods were more supported than those covering shorter time periods and those based on greenness. While drought is but one of myriad environmental variations birds encounter, our results indicate that drought is capable of imposing sizable shifts in abundance, richness, and composition on avian communities, an important implication of a more climatically variable future.
Functional changes in the control of carbon fluxes after 3 years of increased drought in a Mediterranean evergreen forest?
Authors: MISSON LAURENT , ROCHETEAU ALAIN , RAMBAL SERGE , OURCIVAL JEAN‐MARC , LIMOUSIN JEAN‐MARC , RODRIGUEZ RAQUEL
Published: December 2009

Our objective was to test how a long‐term increased water limitation affects structural and functional properties of a Mediterranean ecosystem, and how these changes modify the response of the main carbon fluxes to climatic controls. In 2003, a 27% throughfall exclusion experiment was installed in a Quercus ilex L. forest in France. Gross primary production (GPP), ecosystem respiration (RECO) and net ecosystem exchange (NEE) were estimated in a control and a dry treatment. Decreasing throughfall decreased GPP by 14% and had a smaller effect on RECO (−12%), especially soil respiration RS (−11%). Interannual variability of GPP (29%) was higher than for RECO (12%). Error propagation was used to estimates uncertainties in the NEE fluxes, which ranged from 3% to 10% in the control treatment but up to 167% for NEE in the dry treatment because more steps and data types were involved in the scaling. After 3 years of throughfall exclusion, we found no acclimation of RS to climatic drivers. Functional properties of the response of RS to soil water, temperature and rain pulse remained similar in the control and the dry treatments. A diurnal clockwise hysteresis in RS was probably controlled by canopy photosynthesis with a 3 h lag. The proportion of diurnal variation of respiration due to photosynthesis was similar in all treatments (4–5%). Because of the characteristic of rain in Mediterranean climates, a continuous decrease of water input in these environments have an effect on topsoil water and consequently on RS only during short periods when rainfall is characterized by infrequent and small events that does not allow the topsoil to reach field capacity and does not allow to dry completely. However, in the longer term, we expect a stronger decrease in RS in the dry treatment driven by the decrease in GPP.
Proliferation and apoptotic rates and increased frequency of p63‐positive cells in the prostate acinar epithelium of alloxan‐induced diabetic rats
Authors: Arcolino Fanny Oliveira , Ribeiro Daniele Lisboa , Gobbo Marina Guimarães , Taboga Sebastião Roberto , Góes Rejane Maira
Published: December 2009

The effects of experimental type 1 diabetes were investigated in the acinar epithelium of rat ventral prostate, focusing on the rates of cell proliferation and the frequency of apoptosis and p63‐positive cells. Type 1 diabetes was induced in adult male Wistar rats by a single alloxan administration (42 mg/kg b.w.) and its effects were analysed for 1 week and 3 months after the establishment of the disease. A group of diabetic rats was treated daily with 5 IU of insulin during 1 week after diabetes had been diagnosed. Immunocytochemical methods for the localization of cell proliferation antigen (PCNA), androgen receptor (AR) and p63 protein were carried out, and apoptotic cells were identified by TUNEL essay. In diabetic rats, testosterone levels reduced drastically after 1 week and in a lower degree after 3 months. In short‐term diabetic rats, cell proliferation decreased, and in medium‐term, epithelial apoptotic rates increased. In both periods after the onset of diabetes, the frequency of p63‐positive cells doubled. Insulin treatment was effective in preventing testosterone decrease, p63‐positive cell increase and apoptotic rates, but did not interfere in cell proliferation. This investigation shows that, soon after diabetes onset, there are important modifications in cell proliferation within the acinar prostatic epithelium, and in longer term, there is a marked impact on kinetics of differentiation and cell death, which may initially be attributable to an androgenic fall, but is probably also because of other factors related to diabetes, as changes are considerably different from those resulting from castration.
Quality of life after surgery for rectal cancer with special reference to pelvic floor dysfunction
Authors: Varpe P. , Huhtinen H. , Rantala A. , Salminen P. , Rautava P. , Hurme S. , Grönroos J.
Published: December 2009

Aim  Conventional outcomes such as survival, tumour recurrence and complication rates after surgery for rectal cancer have been rigorously assessed, but the importance of maintaining quality of life (QOL) after surgery for rectal cancer has received less attention. The aim of the current study was to analyse QOL and the occurrence of pelvic dysfunction after the surgical treatment of rectal cancer.

Method  Between May 2005 and May 2008, 150 patients with rectal cancer underwent abdominoperineal resection (APR) or anterior resection (AR). Seventy‐four answered two preoperative questionnaires. At a follow up of 1 year, 65 were alive without sign of recurrence and answered the same questionnaires: (a) validated RAND 36‐item health survey QOL questionnaire; and (b) self‐administered disease‐related questionnaire with special reference to anorectal and urogenital function.

Results  The postoperative general QOL was similar after surgery, and mental functioning was better (P < 0.001). Problems with physical functions were associated with anal dysfunction after AR (P < 0.001) and problems with social functioning were associated with urinary dysfunction (P = 0.038). At 1 year after surgery, urinary incontinence was worse (P = 0.026) after all operations, and the incidence of dysuria was higher after APR than AR (P = 0.001). Male sexual function also worsened (P = 0.060). Anorectal dysfunction caused more inconvenience among patients who underwent AR (P = 0.028). Preoperative radiation was associated with postoperative ejaculation problems (P = 0.028) and anal incontinence (P = 0.012).

Conclusion  Factors affecting QOL and pelvic floor function should be taken into account when making treatment decisions in rectal cancer.
An open study of maintenance antibiotic therapy for chronic antibiotic‐dependent pouchitis: efficacy, complications and outcome
Authors: McLaughlin S. D. , Clark S. K. , Tekkis P. P. , Ciclitira P. J. , Nicholls R. J.
Published: December 2009

Aim  About 5% of restorative proctocolectomy (RPC) patients develop chronic antibiotic‐dependent pouchitis. These require antibiotic maintenance therapy. We report our experience in managing this patient group.

Method  Patients with RPC that was treated with antibiotic maintenance therapy were identified from the hospital pouch database. Data including faecal antibiotic sensitivity, functional outcome, side effects and Cleveland Global Quality of Life (CGQOL) score were recorded.

Results  Twenty‐five patients were identified. The median length of treatment was 15.8 (range 3–62) months. Ten (40%) patients had pouchitis with co‐existing prepouch ileitis. The median frequency of defecation was 7 (range 4–11)/24 h, the median clinical Pouch Disease Activity Index (PDAI) was 0 (range 0–1) and the CQGOL score was 0.7 (range 0.5–1.0). Of those who relapsed, three (50%) patients had achieved mucosal healing following the induction of remission. Failure of mucosal healing did not predict a reduced time to relapse (P = 0.18). Prepouch ileitis was associated with an increased risk of developing antibiotic resistance (P = 0.023). Treatment of this with alternating antibiotic combination therapy was successful in all cases.

Conclusion  Antibiotic maintenance therapy appears safe, well‐tolerated and effective for the treatment of chronic antibiotic‐dependent pouchitis. It results in an improved quality of life and function. Prepouch ileitis, but not failure of mucosal healing, is associated with an increased risk of developing antibiotic resistance.
The National Bowel Cancer Audit: the risks and benefits of moving to open reporting of clinical outcomes
Authors: Thompson M. R. , Tekkis P. P. , Stamatakis J. , Smith J. J. , Wood L. F. , Von Hildebrand M. , Poloniecki J. D.
Published: December 2009

Background  The government’s proposals to openly report clinical outcomes poses challenges to the National Bowel Cancer Audit now funded by the UK department of health.

Aim  To identify the benefits and risks of open reporting and to propose ways the risks might be minimized.

Methods  A review of the literature on clinical audit and the consequences of open reporting.

Results  There are significant potential benefits of a national audit of bowel cancer including protecting patients from sub‐standard care, providing clinicians with externally validated evidence of their performance, outcome data for clinical governance and evidence that increases in government expenditure are achieving improvements in survival from bowel cancer. These benefits will only be achieved if the audit captures most of the cases of bowel cancer in the UK, the data collected is complete and accurate, the results are risk adjusted and these are presented to the public in a way that is fair, clear and understandable. Involvement of clinicians who have confidence in the results of the audit and who actively compare their own results against a national standard is essential. It is suggested that a staged move to open reporting should minimise the risk of falsely identifying an outlying unit.

Conclusion  The fundamental aim of the National Bowel Cancer Audit is the pursuit of excellence by identification and adoption of best practice. This could achieve a continuous improvement in the care of all patients with bowel cancer in the UK. The ACPGBI suggests a safer way of transition to open reporting to avoid at least some of its pitfalls.
Interaction between synchronous bilateral prophylactic oophorectomy and adjuvant chemotherapy in female patients with locally advanced colorectal cancer
Authors: Cai G. X. , Xu Y. , Tang D. F. , Lian P. , Peng J. J. , Wang M. H. , Guan Z. Q. , Cai S. J.
Published: December 2009

Aim  In this study we explored the prognostic impact of synchronous bilateral prophylactic oophorectomy in female patients with primary colorectal cancer undergoing radical surgery.

Method  From 1991 to 2000, 267 female patients with stage II or stage III colorectal cancer, who had undergone curative resection, were retrospectively reviewed. In 224 patients, the ovaries were preserved. The other 43 patients underwent synchronous bilateral prophylactic oophorectomy. Univariate and multivariate analyses (Kaplan–Meier and Cox regression, respectively) were used to evaluate the effect of prophylactic oophorectomy and other clinical factors on the prognosis of patients.

Results  Both univariate and multivariate analyses showed that tumor stage and adjuvant chemotherapy were the only two significant clinical factors that affected the 5‐year overall survival of patients (P < 0.01). There was no significant difference in the 5‐year overall survival between patients who had, or had not, undergone prophylactic oophorectomy (75%vs 73%, P > 0.05). In the subgroup analysis by adjuvant chemotherapy, the 5‐year overall survival in patients receiving adjuvant chemotherapy was similar between nonoophorectomy and oophorectomy groups. However, in patients without adjuvant chemotherapy, the oophorectomy group was shown to have a significantly better 5‐year overall survival than the nonoophorectomy group (76%vs 51%, P = 0.047).

Conclusion  Prophylactic oophorectomy may improve the overall survival of female patients with locally advanced colorectal cancer without adjuvant chemotherapy, but its survival benefit vanished in patients receiving adjuvant chemotherapy. The role of prophylactic oophorectomy may be substituted by adjuvant chemotherapy, which makes prophylactic oophorectomy unnecessary during surgery for locally advanced colorectal cancer.
How Does Cross‐Border Activity Affect EU Banking Markets?
Authors: Lozano‐Vivas Ana , Weill Laurent
Published: December 2009

Cross‐border activity in the EU is widely viewed as a necessary condition for the implementation of a single banking market and therefore as a positive factor for the enhancement of competition and cost performance in the region. In this paper, we analyse the relevance of this view by investigating whether cross‐border activity really promotes competition and cost efficiency in EU banking markets. We also consider the potential role of a bank's mode of entry by comparing existing domestic banks that foreign banks take over (mergers and acquisitions) with new branches created by foreign banks, often through subsidiaries (greenfield operations). We consider the impact of cross‐border banks on cost efficiency (measured by the stochastic frontier approach), profitability (assessed through return on assets) and competition (measured by the Lerner index). We find that greenfield banks enhance cost efficiency and competition, while mergers and acquisitions hamper competition and cost efficiency. Therefore, our results suggest that EU authorities should promote only greenfield banks rather than all cross‐border entries.
Exchange Rate Policy: The Euro Area, the United States and Asia*
Authors: Coutinho Leonor
Published: December 2009

This paper uses a three‐country stylized model of the United States, the euro area and Asia to analyse alternative policy responses to an exogenous depreciation of the US dollar. It is assumed that the Asian authorities respond by maintaining their peg to the dollar, while the European Central Bank (ECB) can either maintain its monetary policy stance or attempt to stabilize the euro's exchange rate. Using simulations, we find that in many cases, it is not optimal for the ECB to try to offset euro appreciation. The basic results are driven by the degree of substitutability among US, euro area and Asian goods, and the degree of product market competition within each market.