bluuebunny/crossref_metadata_2025 huggingface dataset:
Raman spectroscopy and ab initio investigations of transient complex formation in CO2-benzene mixtures
Authors: Besnard M. , Cabaço M. Isabel , Talaga D. , Danten Y.
Published: December 2008

The polarized and depolarized Raman spectra of CO2 have been measured as a function of CO2 concentration (0.02–0.7 molar fractions) in the dense phase of the binary mixtures obtained by introducing under pressure (from 0.2 up to 6.0 MPa) supercritical carbon dioxide (at 313 K) in liquid benzene. Four main experimental features are observed. A new weak polarized band centered at approximately 660 cm−1 has been detected in the region of the Raman inactive ν2 bending mode of carbon dioxide. The analysis of the polarized band shapes of the Fermi dyad shows that CO2 molecules probe two environments. In one of them carbon dioxide interacts “specifically” with benzene molecules, whereas in the other it interacts “nonspecifically” with its neighbors. The analysis of the depolarized Fermi dyad profiles shows that the rotational dynamics of CO2 specifically interacting with benzene is strongly hindered. Finally, a new weak polarized band has been detected between the two components of the dyad. These observations rationalized at the light of ab initio calculations show that CO2-benzene transient complexes are formed. It is argued that ab initio predictions, limited here to a pair of molecules, are still valid in dense phase because the elementary act of formation of the transient complex can be probed on the observation time and spatial range of vibrational Raman spectroscopy.
Modeling bulk and surface Pt using the “Gaussian and plane wave” density functional theory formalism: Validation and comparison to k-point plane wave calculations
Authors: Santarossa Gianluca , Vargas Angelo , Iannuzzi Marcella , Pignedoli Carlo A. , Passerone Daniele , Baiker Alfons
Published: December 2008

We present a study on structural and electronic properties of bulk platinum and the two surfaces (111) and (100) comparing the Gaussian and plane wave method to standard plane wave schemes, normally employed for density functional theory calculations on metallic systems. The aim of this investigation is the assessment of methods based on the expansion of the Kohn–Sham orbitals into localized basis sets and on the supercell approach, in the description of the metallicity of Pt. Electronic structure calculations performed at Γ-point only on supercells of different sizes, from 108 up to 864 atoms, are compared to the results obtained for the unit cell of four Pt atoms where the k-point expansion of the wave function over Monkhorst–Pack grids up to (10×10×10) has been employed. The evaluation of the two approaches with respect to bulk properties is done through the calculation of the equilibrium lattice constant, the bulk modulus, and the total and the d-projected density of states. For the Pt(111) and Pt(100) surfaces, we consider the relaxation of the first layers, the surface energies, the work function, the total density of states, as well as the center and filling of the d bands. Our results confirm that the accuracy of two approaches in the description of electronic and structural properties of Pt is equivalent, providing that consistent supercells and k-point meshes are used. Moreover, we estimate the supercell size that can be safely adopted in the Gaussian and plane wave method in order to obtain the same reliability of previous theoretical studies based on well converged plane wave calculations available in literature. The latter studies, in turn, set the level of agreement with experimental data. In particular, we obtain excellent agreement in the evaluation of the density of states for either bulk and surface systems, and our data are also in good agreement with previous works on Pt reported in literature. We conclude that Gaussian and plane wave calculations, with simulation cells of 400–800 atoms, can be safely used in the study of chemistry related problems involving transition metal surfaces.
Double photoionization of thiophene and bromine-substituted thiophenes
Authors: Linusson P. , Storchi L. , Heijkenskjöld F. , Andersson E. , Elshakre M. , Pfeifer B. , Colombet M. , Eland J. H. D. , Karlsson L. , Rubensson J.-E. , Tarantelli F. , Feifel R.
Published: December 2008

We report the double photoionization spectra of thiophene, 3-bromothiophene, and 3,4-dibromothiophene using a coincidence spectroscopy technique based on electron time-of-flight measurements. Spectra have been recorded between the onset and 40.814 eV using He IIα radiation. The He I photoelectron spectrum of 3,4-dibromothiophene has also been measured. All the spectra have been analyzed and interpreted in detail on the basis of theoretical simulations from accurate Green’s function calculations.
Thermodynamic state dependence of orientational order and rotational relaxation in carbon tetrachloride
Authors: Rey Rossend
Published: December 2008

Molecular dynamics simulations show that orientational correlations in carbon tetrachloride span a wide range of distances within the phases that are ordinarily described as orientationally disordered. They are long ranged in the plastic crystal phase, reach up to several solvation layers in the liquid phase, and only involve contact neighbors within the gas phase. On the contrary, short range arrangements are rather similar, with the sequence face-to-face, edge-to-face, and edge-to-edge describing the most populated relative orientations for increasing distances. In what concerns rotational relaxation, it is shown that none of the available theories is able to describe the relationship between rotational relaxation and angular velocity relaxation times for the three phases studied. This is at variance with experimental results obtained long ago for carbon tetrafluoride, which were in excellent accord with J-diffusion, but is in line with recent experimental results for deuterated methane in gas-phase mixtures.
Dynamics of hydrogen dissociation on stepped platinum
Authors: Groot I. M. N. , Schouten K. J. P. , Kleyn A. W. , Juurlink L. B. F.
Published: December 2008

We have studied the reactivity of hydrogen on the Pt(211) stepped surface using supersonic molecular beam techniques. We observe an energy dependence that is indicative of indirect adsorption below 9kJmol−1 and direct adsorption between 0 and 37kJmol−1. Comparison of our results to predictions based on six-dimensional quantum dynamics calculations for Pt(211) [R. A. Olsen et al., J. Chem. Phys. 128, 194715 (2008)] yields reasonable agreement. Discrepancies between theory and our experiments at low kinetic energy strongly indicate that the wells in the used potential energy surface are too shallow. Discrepancies at high kinetic energy point toward neglect of degrees of freedom vital to capture the full dynamics.
Using metal-organic templates to steer the growth of Fe and Co nanoclusters
Authors: Decker R. , Schlickum U. , Klappenberger F. , Zoppellaro G. , Klyatskaya S. , Ruben M. , Barth J. V. , Brune H.
Published: December 2008

Regularly sized Fe and Co nanostructures are created using two-dimensional metal-organic honeycomb lattices as templates. They consist of dicarbonitrile-polyphenyl molecules coordinated to Co centers on Ag(111). Subsequently deposited Fe or Co atoms nucleate clusters at specific sites on top of the metal-organic lattices while leaving their hexagonal pores empty. Choosing the deposition temperature, one can selectively decorate the molecules (120K) or the Co coordination nodes (190K) with Fe. The distance between the Fe and Co clusters and their shape can be adjusted through the lattice constant of the template by varying the number of phenyl rings in the molecules.
Depth-resolved holographic optical coherence imaging using a high-sensitivity photorefractive polymer device
Authors: Salvador M. , Prauzner J. , Köber S. , Meerholz K. , Jeong K. , Nolte D. D.
Published: December 2008

We present coherence-gated holographic imaging using a highly sensitive photorefractive (PR) polymer composite as the recording medium. Due to the high sensitivity of the composite holographic recording at intensities as low as 5 mW/cm2 allowed for a frame exposure time of only 500ms. Motivated by regenerative medical applications, we demonstrate optical depth sectioning of a polymer foam for use as a cell culture matrix. An axial resolution of 18 μm and a transverse resolution of 30 μm up to a depth of 600 μm was obtained using an off-axis recording geometry.
Coupling of nitrogen-vacancy centers in diamond to a GaP waveguide
Authors: Fu K.-M. C. , Santori C. , Barclay P. E. , Aharonovich I. , Prawer S. , Meyer N. , Holm A. M. , Beausoleil R. G.
Published: December 2008

The optical coupling of guided modes in a GaP waveguide to nitrogen-vacancy (NV) centers in diamond is demonstrated. The electric field penetration into diamond and the loss of the guided mode are measured. The results indicate that the GaP-diamond system could be useful in realizing coupled microcavity-NV devices for quantum information processing in diamond.
A terraced scanning super conducting quantum interference device susceptometer with submicron pickup loops
Authors: Koshnick Nicholas C. , Huber Martin E. , Bert Julie A. , Hicks Clifford W. , Large Jeff , Edwards Hal , Moler Kathryn A.
Published: December 2008

Superconducting quantum interference devices (SQUIDs) can have excellent spin sensitivity depending on their magnetic flux noise, pickup loop diameter, and distance from the sample. We report a family of scanning SQUID susceptometers with terraced tips that position the pickup loops 300nm from the sample. The 600nm–2μm pickup loops, defined by focused ion beam, are integrated into a 12-layer optical lithography process allowing flux-locked feedback, in situ background subtraction and optimized flux noise. These features enable a sensitivity of ∼70 electron spins per root hertz at 4K.
Design of an efficient light-emitting diode with 10 GHz modulation bandwidth
Authors: Fattal D. , Fiorentino M. , Tan M. , Houng D. , Wang S. Y. , Beausoleil Raymond G.
Published: December 2008

We present a high-speed light-emitting-diode (LED) design for efficient modulation at speeds higher than 10 GHz. It relies on a tensile-strain GaAsP quantum well coupled with surface plasmon polaritons on a silver surface. We present optical pumping experiments showing a tenfold reduction in carrier lifetime when the quantum well is located 40 nm above the silver surface. We believe this represents the first step toward an efficient LED compatible with 10 GHz modulation speed for use in short distance optical communication systems.
Single-cycle azimuthal angle dependence of terahertz radiation from (100) n-type InP
Authors: Hargreaves S. , Lewis R. A.
Published: December 2008

We have observed that the terahertz power emitted by (100) n-type InP exhibits a single maximum and a single minimum as the crystal is rotated through 360° about its surface normal. This stands in contrast to other semiconductor terahertz emitters for which two, three, or four maxima per rotation have been observed. We have investigated the terahertz emission as a function of sample doping, optical excitation fluence, and applied in-plane magnetic field. The data cannot be accounted for by bulk optical rectification. We suggest that the origin of the phenomenon may be related to crystal twinning.
Enhanced contrast coherent anti-Stokes Raman scattering microscopy using annular phase masks
Authors: Beversluis Michael R. , Stranick Stephan J.
Published: December 2008

We have experimentally demonstrated enhanced image contrast of sample fine structure in a coherent anti-Stokes Raman scattering (CARS) microscope using liquid crystal spatial light modulators as programmable Toraldo-style pupil phase masks. We demonstrated through modeling, implementation, and verification of the focal intensity and phase distributions of the excitation beams the trade-offs between improved image contrast and CARS signal levels.
Cathodoluminescence inhomogeneity in ZnO nanorods
Authors: Foley Matthew , Ton-That Cuong , Phillips Matthew R.
Published: December 2008

Luminescence properties of vertically aligned, crystalline ZnO nanorods are studied by cathodoluminescence (CL) spectroscopy and microscopy. Results show that luminescence characteristics vary dramatically with location on the nanorod as well as CL excitation depth. CL inhomogeneity is observed between the nanorod tip and sidewalls, accompanied by a variation in the chemical environment of surface oxygen ions as probed by photoemission spectroscopy. Our findings demonstrate that CL can provide useful information on the local optical properties of nanostructured materials, which is simply beyond the capability of other methods.
Current-induced flip-flop of magnetization in magnetic tunnel junction with perpendicular magnetic layers and polarization-enhancement layers
Authors: Kim Woojin , Lee Taek Dong , Lee Kyung-Jin
Published: December 2008

We performed a micromagnetic investigation of current-induced magnetization switching in perpendicular magnetic tunnel junctions with polarization-enhancement layers. The pinned layer with a polarization-enhancement layer can be excited and eventually reverses at a current density lower than the value theoretically expected from that without a polarization-enhancement layer. The reversal results in continuous flip-flops of magnetizations as long as the current is applied. The flip-flop occurs at only one current polarity, caused by the precession amplification in polarization-enhancement layer. In order to prevent the unwanted flip-flop, the perpendicular anisotropy of the pinned layer must be severalfold larger than that of the free layer.
Elliptically polarized terahertz emission in the forward direction of a femtosecond laser filament in air
Authors: Chen Yanping , Marceau Claude , Liu Weiwei , Sun Zhen-Dong , Zhang Yizhu , Théberge Francis , Châteauneuf Marc , Dubois Jacques , Chin See Leang
Published: December 2008

Elliptically polarized terahertz emission from a femtosecond laser filament in air in the forward direction was discovered by using a wire grid polarizer and electro-optic sampling technique. The generation mechanism could be through four-wave optical rectification or second-order optical rectification inside the filament zone where the inversion symmetry of air is broken.
Probing antiphase boundaries in Fe3O4 thin films using micro-Raman spectroscopy
Authors: Tiwari Shailja , Phase D. M. , Choudhary R. J.
Published: December 2008

We present Raman study of Fe3O4 films of different thicknesses grown on single crystal Si and MgO substrates to investigate the presence of antiphase boundaries (APBs). X-ray diffraction and x-ray photoelectron spectroscopy measurements indicate that films are single phase Fe3O4 on both the substrates. The changes in frequency and linewidth of different Raman modes [A1g and T2g(3)] are monitored and the electron-phonon coupling parameter (λ) is computed. λ is correlated with the combined effect of strain and APBs present in the grown films and it is concluded that the films grown on Si substrates are free from APBs.
Dielectric properties of Ba0.5Sr0.5TiO3/SiN bilayered thin films grown on Pt-coated sapphire substrates
Authors: Xiong Niandeng , Jiang Shuwen , Li Yanrong , Tan Lefan , Li Ruguan
Published: December 2008

The Ba0.5Sr0.5TiO3(BST)/SiN bilayered thin films with a SiN layer serving as a buffer layer between the top electrode and the BST layer have been prepared onto Pt-coated c-plane sapphire substrates. The dielectric measurements show that the loss tangent has been significantly lowered. The dielectric properties of the BST/SiN bilayered thin films are strongly dependent on the SiN thickness. The BST/SiN bilayered thin films at a SiN/BST thickness ratio of 0.2 give the largest figure of merit of 50.1. The thickness effect was discussed as well with a series connection model of multilayered capacitors, and the favorable simulation was obtained.
Enhanced conversion efficiency in dye-sensitized solar cells based on ZnO bifunctional nanoflowers loaded with gold nanoparticles
Authors: Dhas Vivek , Muduli Subas , Lee Wonjoo , Han Sung-Hwan , Ogale Satishchandra
Published: December 2008

The ZnO nanoflowers loaded with gold (Au) nanoparticles (NPs) are synthesized by a hydrothermal route using mixed precursors and controlled conditions. The dye-sensitized solar cells based on the ZnO nanoflowers with Au NPs show power conversion efficiency of 2.5%, which is considerably higher than that of ZnO nanoflowers without Au NPs. Detailed characterizations are performed, presented, and discussed.
Self-assembly of functionally gradient nanoparticle structures
Authors: Park Jonghyun , Lu Wei
Published: December 2008

Morphology control of binary nanoparticles in an electric field was investigated by a computational model. The study revealed rich patterning dynamics and how collective actions of relative permittivity, volume fraction, and particle size can lead to a wide range of superlattice structures from functionally gradient columns to chain networks. These results suggest a significant degree of experimental control to assemble binary nanoparticles into new materials.
Formation of color centers in nanodiamonds by plasma assisted diffusion of impurities from the growth substrate
Authors: Aharonovich Igor , Zhou Chunyuan , Stacey Alastair , Treussart François , Roch Jean-François , Prawer Steven
Published: December 2008

A technique to create nickel-related single color centers in individual nanodiamonds is demonstrated. The method involves implantation of nickel ions into a substrate onto which the diamond nanocrystals are subsequently grown by chemical vapor deposition. The nickel is transported during the growth from the implanted substrate to the plasma and incorporates itself into the growing nanodiamonds. The nanodiamonds grown by this method reveal narrow photoluminescence peaks and proved to be single photon emitters. The results demonstrate a significant advance in the control of nickel-related color centers in diamond which are core candidates for quantum information processing.
Temperature-driven phase transitions in SrBi2Ta2O9 from first-principles calculations
Authors: Machado R. , Sepliarsky M. , Stachiotti M. G.
Published: December 2008

The phase transition sequence of SrBi2Ta2O9 is investigated using a shell model with parameters fitted to first-principles calculations. We show that the complex interplay between polar and nonpolar instabilities leads to the presence of two phase transitions, corroborating the existence of an intermediate orthorhombic paraelectric phase. This phase is characterized by the rotation of the TaO6 octahedra around the a axis. We show that this phase can also be detected from the dielectric response of the material. The present approach constitutes a powerful tool for a theoretical prediction of intermediate phases, not yet observed experimentally, in other Aurivillius compounds.
Sustainable Urban Development and the Challenge of Policy Integration: An Assessment of Planning Tools for Integrating Spatial and Environmental Planning in the Netherlands
Authors: Runhaar Hens , Driessen Peter P J , Soer Laila
Published: December 2008

Over the last 10–15 years, urban planners in the Netherlands have been given more policy space for defining area-specific environmental ambitions, in an attempt to promote further the integration of environmental and urban planning. This increased policy space has offered new opportunities, but also poses new challenges for urban planners. Urban planners often appear to struggle with the issue of how to come to an operationalization of area-specific urban environmental quality. Various planning tools exist that can assist planners with these tasks. In this paper we distinguish between ‘substance-oriented’ tools such as environmental impact assessments and ‘process-oriented’ tools that facilitate interaction and consensus building among planners and stakeholders. Recently, in the Netherlands, a distinct type of ‘hybrid’ planning tool has been developed specifically for defining area-based environmental ambitions in spatial plans, coupled with the development of measures for attaining these ambitions. However, little research has been conducted into how these planning tools perform in practice and how this can be understood, especially in comparison with more traditional ‘substance-oriented’ and ‘process-oriented’ planning tools. In this paper we assess the added value of the new hybrid tools on the basis of an analysis of three exemplary case studies. Although the tools seem to be helpful in assisting urban planners to better integration of environmental and spatial planning, there are some aspects that deserve more attention, including the identification of financial consequences of environmental ambitions, and guidelines for dealing with controversies. Future research is recommended into the influence of the hybrid tools on their sociopolitical contexts, their performance in comparison with other hybrid planning tools, and their effective design.
Characterisation of BcMF10, a novel gene involved in pollen wall development of Brassica rapa ssp. chinensis
Authors: Huang Li , Cao Jiashu , Zhang Ai-Hong , Zhang Yu-Chao , Ye Yi-Qun
Published: December 2008

Comparative expression profiling of flower buds in two male sterile lines [genic male sterile (GMS) and cytoplasmic male sterile (CMS)] with its male fertile maintainer line in Chinese cabbage pak-choi was performed using cDNA-AFLP technology to identify the genes implicated in male sterility. A novel gene BcMF10, sharing high sequence similarity to the function-unknown DUF1216 family in Arabidopsis was isolated, whose expression was absent in the flower buds of the GMS and CMS lines but present in the male fertile maintainer line. Temporal and spatial expression pattern analysis revealed that BcMF10 began to be expressed in tapetal cells and microspores during meiosis. Expression in tapetal cells was persistent until the degeneration of tapetum, and expression in microspores reached a peak during the tetrad stage but gradually declined as development proceeded. RNA interference technology was used to address the biological function of BcMF10. The RNAi transgenic Chinese cabbage pak-choi lines showed normal vegetative growth and reproductive development, but poor pollen germination. Scanning electron microscopy (SEM) showed that most of the transgenic pollen was deformed and exhibited an irregular shape with an abnormal number and distribution of germinal furrows. It is speculated that BcMF10 may encode a protein that plays a role in the formation of intine wall.
The harvest-responsive region of the Asparagus officinalis sparagine synthetase promoter reveals complexity in the regulation of the harvest response
Authors: Hunter Donald A. , Watson Lyn M.
Published: December 2008

The activity of a 1915-bp asparagine synthetase (AS) promoter of Asparagus officinalis L. was induced in mature leaves of transgenic Arabidopsis thaliana (L.) Heynh. plants when the leaves were detached and held in water for 24 h. To understand this induction by harvest, variants of the AS promoter were linked to the β-glucuronidase GUS reporter gene. Harvest induction in the leaves required detachment and was not simply a wound response. Two regions in the AS promoter (Region A, –640 to –523; Region B, –524 to –383) were independently able to confer harvest response to the otherwise unresponsive –383AS (minimal) promoter. Region A was studied in further detail. Various truncations, deletions, or nucleotide substitutions of Region A affected activity and fold induction of the minimal promoter. However, no harvest-inducible cis-acting element within Region A was identified. Although the minimal promoter contained a dehydration-responsive element and ACGT elements similar to ABA-responsive regulatory motifs these were not needed by the upstream regulatory regions for directing harvest response. When four copies of Region A were linked to the minimal promoter it became highly active in leaves before harvest. Deletions within Region A showed that it required its complete 117 bp for driving harvest response, yet the region cannot simply be thought of as a harvest-responsive module, since its concatemerisation led to constitutive expression.
Rooting depth and leaf hydraulic conductance in the xeric tree Haloxyolon ammodendron growing at sites of contrasting soil texture
Authors: Xu G.-Q. , Li Y.
Published: December 2008

An experiment was conducted on Haloxylon ammodendron C.A. Mey, a small xeric tree. Soil water content, soil evaporation, leaf water potential, leaf transpiration rate and stomatal conductance were measured at the two sites that contrast in soil texture: sandy and heavy textured, 8 km apart on the southern periphery of Gurbantonggut Desert, Central Asia, during the 2005 and 2006 growing seasons. Leaf specific hydraulic conductance was calculated from the measurements, and root distributions of plants grown at the two sites were quantified by whole-root system excavation. In general, plants grown in sandy soil experienced better water status than in heavy textured soil. Low soil evaporation loss is not the main reason for this better plant water status at sandy site. Plants in sandy soil developed much deeper root systems, larger root surface areas and higher root: leaf surface area ratio than in heavy textured soil, which facilitated plants acquiring more water and surviving the prolonged drought period. Plants growing at light textured sites should have an advantage in acclimatising to the changed water conditions of the future. Plants at the more sandy sites have a larger buffering capacity to excessive variation in ambient conditions.
Plant extracellular matrix metalloproteinases
Authors: Flinn Barry S.
Published: December 2008

The plant extracellular matrix (ECM) includes a variety of proteins with critical roles in the regulation of plant growth, development, and responses to pests and pathogens. Several studies have shown that various ECM proteins undergo proteolytic modification. In mammals, the extracellular matrix metalloproteinases (MMPs) are known modifiers of the ECM, implicated in tissue architecture changes and the release of biologically active and/or signalling molecules. Although plant MMPs have been identified, little is known about their activity and function. Plant MMPs show structural similarity to mammalian MMPs, including the presence of an auto-regulatory cysteine switch domain and a zinc-binding catalytic domain. Plant MMPs are differentially expressed in cells and tissues during plant growth and development, as well as in response to several biotic and abiotic stresses. The few gene expression and mutant analyses to date indicate their involvement in plant growth, morphogenesis, senescence and adaptation and response to stress. In order to gain a further understanding of their function, an analysis and characterisation of MMP proteins, their activity and their substrates during plant growth and development are still required. This review describes plant MMP work to date, as well as the variety of genomic and proteomic methodologies available to characterise plant MMP activity, function and potential substrates.
The RAD51 gene family in bread wheat is highly conserved across eukaryotes, with RAD51A upregulated during early meiosis
Authors: Khoo Kelvin H. P. , Jolly Hayley R. , Able Jason A.
Published: December 2008

The RADiation sensitive protein 51 (RAD51) recombinase is a eukaryotic homologue of the bacterial Recombinase A (RecA). It is required for homologous recombination of DNA during meiosis where it plays a role in processes such as homology searching and strand invasion. RAD51 is well conserved in eukaryotes with as many as four paralogues identified in vertebrates and some higher plants. Here we report the isolation and preliminary characterisation of four RAD51 gene family members in hexaploid (bread) wheat (Triticum aestivum L.). RAD51A1, RAD51A2 and RAD51D were located on chromosome group 7, and RAD51C was on chromosome group 2. Q-PCR gene expression profiling revealed that RAD51A1 was upregulated during meiosis with lower expression levels seen in mitotic tissue, and bioinformatics analysis demonstrated the evolutionary linkages of this gene family to other eukaryotic RAD51 sequences. Western blot analysis of heterologously expressed RAD51 from bread wheat has shown that it is detectable using anti-human RAD51 antibodies and that molecular modelling of the same protein revealed structural conservation when compared with yeast, human, Arabidopsis and maize RAD51A orthologues. This report has widened the knowledge base of this important protein family in plants, and highlighted the high level of structural conservation among RAD51 proteins from various species.
Portable PIT detector as a new tool for non-disruptively locating individually tagged amphibians in the field: a case study with Pyrenean brook salamanders (Calotriton asper)
Authors: Cucherousset J. , Marty P. , Pelozuelo L. , Roussel J.-M.
Published: December 2008

Passive Integrated Transponder (PIT) telemetry has recently been adapted for locating PIT-tagged fish in shallow waters using portable detectors. In the present study, we tested this method for adult amphibians (Pyrenean brook salamanders, Calotriton asper) PIT-tagged with 12-mm transponders in a headwater rocky stream. PIT telemetry performances were compared with a conventional hand-capture method, i.e. visual searching and overturning movable stones in the streambed. The mean efficiency of the portable detector (88.2% ± 5.2, s.e.) was significantly higher than hand-capture (51.1% ± 6.4) and the operator progressed, on average, four times faster. Time efficiencies were, on average, 0.92 (±0.15) and 0.12 (±0.04) adult salamanders per minute with the portable detector and by hand-capture, respectively. The efficiency of the portable detector was negatively correlated with the percentage of large stones on the streambed. The time needed to prospect a section was positively correlated with the abundance of PIT-tagged adult salamanders, spring inlets and undercut banks. Because PIT telemetry is less disruptive than hand-capture for both salamanders and their habitat, it is a promising and non-disruptive method for developing studies on the ecology and management of amphibians in shallow waters.
A handcuff model for the cohesin complex
Authors: Zhang Nenggang , Kuznetsov Sergey G. , Sharan Shyam K. , Li Kaiyi , Rao Pulivarthi H. , Pati Debananda
Published: December 2008

The cohesin complex is responsible for the accurate separation of sister chromatids into two daughter cells. Several models for the cohesin complex have been proposed, but the one-ring embrace model currently predominates the field. However, the static configuration of the embrace model is not flexible enough for cohesins to perform their functions during DNA replication, transcription, and DNA repair. We used coimmunoprecipitation, a protein fragment complement assay, and a yeast two-hybrid assay to analyze the protein–protein interactions among cohesin subunits. The results show that three of the four human cohesin core subunits (Smc1, Smc3, and Rad21) interact with themselves in an Scc3 (SA1/SA2)-dependent manner. These data support a two-ring handcuff model for the cohesin complex, which is flexible enough to establish and maintain sister chromatid cohesion as well as ensure the fidelity of chromosome segregation in higher eukaryotes.
Na+ channels get anchored…with a little help
Authors: Rasband Matthew N.
Published: December 2008

Neurons have high densities of voltage-gated Na+ channels that are restricted to axon initial segments and nodes of Ranvier, where they are responsible for initiating and propagating action potentials. New findings (Bréchet, A., M.-P. Fache, A. Brachet, G. Ferracci, A. Baude, M. Irondelle, S. Pereira, C. Leterrier, and B. Dargent. 2008. J. Cell Biol. 183:1101–1114) reveal that phosphorylation of several key serine residues by the protein kinase CK2 regulates Na+ channel interactions with ankyrin G. The presence of CK2 at the axon initial segment and nodes of Ranvier provides a mechanism to regulate the specific accumulation and retention of Na+ channels within these important domains.
An extension of the Maskit slice for 4-dimensional Kleinian groups
Authors: Araki Yoshiaki , Ito Kentaro
Published: December 2008

LetΓ\Gammabe a33-dimensional Kleinian punctured torus group with accidental parabolic transformations. The deformation space ofΓ\Gammain the group of Möbius transformations on the22-sphere is well known as the Maskit sliceM1,1{\mathcal {M}}_{1,1}of punctured torus groups. In this paper, we study deformationsΓ′\Gamma ’ofΓ\Gammain the group of Möbius transformations on the33-sphere such thatΓ′\Gamma ’does not contain screw parabolic transformations. We will show that the space of the deformations is realized as a domain of33-spaceR3\mathbb {R}^3, which contains the Maskit sliceM1,1{\mathcal {M}}_{1,1}as a slice through a plane. Furthermore, we will show that the space also contains the Maskit sliceM0,4\mathcal {M}_{0,4}of fourth-punctured sphere groups as a slice through another plane. Some of the other slices of the space will be also studied.
A Review of Nontraditional Biomanipulation
Authors: Zhang Xia , Xie Ping , Huang Xiaoping
Published: December 2008

The aim of this review is to identify problems, find general patterns, and extract recommendations for successful management using nontraditional biomanipulation to improve water quality. There are many obstacles that prevent traditional biomanipulation from achieving expectations: expending largely to remove planktivorous fish, reduction of external and internal phosphorus, and macrophyte re-establishment. Grazing pressure from large zooplankton is decoupled in hypereutrophic waters where cyanobacterial blooms flourish. The original idea of biomanipulation (increased zooplankton grazing rate as a tool for controlling nuisance algae) is not the only means of controlling nuisance algae via biotic manipulations. Stocking phytoplanktivorous fish may be considered to be a nontraditional method; however, it can be an effective management tool to control nuisance algal blooms in tropical lakes that are highly productive and unmanageable to reduce nutrient concentrations to low levels.

Although small enclosures increase spatial overlap between predators and prey, leading to overestimates of the impact of predation, microcosm and whole-lake experiments have revealed similar community responses to major factors that regulate lake communities, such as nutrients and planktivorous fish. Both enclosure experiments and large-scale observations revealed that the initial phytoplankton community composition greatly impacted the success of biomanipulation. Long-term observations in Lake Donghu and Lake Qiandaohu have documented that silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) (two filter-feeding planktivorous species commonly used in management) can suppress Microcystis blooms efficiently. The introduction of silver and bighead carp could be an effective management technique in eutrophic systems that lack macrozooplankton. We confirmed that nontraditional biomanipulation is only appropriate if the primary aim is to reduce nuisance blooms of large algal species, which cannot be controlled effectively by large herbivorous zooplankton. Alternatively, this type of biomanipulation did not work efficiently in less eutrophic systems where nanophytoplankton dominated.
Effects of Temperature, Salinity, pH, and Light on Filtering and Grazing Rates of a Calanoid Copepod (Schmackeria dubia)
Authors: Li Changling , Luo Xiaoxia , Huang Xianghu , Gu Binhe
Published: December 2008

Calanoid copepods are key components of the marine food web and the food sources of many larval fishes and planktivores, and grazers of phytoplankton. Understanding the ranges of major environmental variables suitable for their growth is essential to maintain the balance between trophic links and resources protection. In this study, the effects of temperature, salinity, pH, and light intensity on the filtering and grazing rates of a herbivorous copepod (Schmackeria dubia) were conducted in several control experiments. Our results indicated that experimental animals grazed normally at water temperatures between 15 and 35°C. The filtering and grazing rates increased by onefold at water temperatures from 15 to 25°C, with a peak at around 30°C.S. dubiafed normally at salinity ranging from 20 to 30 ppt, with significantly low filtering and grazing rates at salinity below 15 ppt and above 35 ppt. The filtering and grazing rates increased as pH increased, peaked at approximately 8.5, and then decreased substantially. Light intensity also displayed an important impact on the filtering and grazing rates. Filtering and grazing rates were high when light intensity was greater than 20 and less than 200 µmol m-2s-1. S. dubia nearly stopped feeding at low light intensity (less than 20 µmol m-2s-1).
Recent advances in the molecular pathology of soft tissue sarcoma: Implications for diagnosis, patient prognosis, and molecular target therapy in the future
Authors: Oda Yoshinao , Tsuneyoshi Masazumi
Published: December 2008

In the present paper, recent advances in the molecular pathology of soft tissue sarcomas (STS) and the implications for their prognostic value are reviewed, and the potential targets of molecular therapy are discussed. According to the molecular genetic aspect, STS are divided into two groups: chromosome translocation‐associated sarcomas and sarcomas without specific translocation. In the former group, specific fusion transcripts, such as SS18–SSX, EWS–FLI1, and PAX3–FKHR, could be detected in synovial sarcoma, Ewing's sarcoma and primitive neuroectodermal tumor, and alveolar rhabdomyosarcoma, respectively. The direct or indirect interactions between these fusion transcripts and cell cycle regulators have been elucidated by several investigators. Therefore, these fusion transcripts are promising candidates as molecular targets. As evaluated in carcinomas, alterations of several tumor‐suppressor genes and adhesion molecules and overexpression of growth factors and their receptors have been extensively assessed in STS. In mixed‐type STS, epidermal growth factor receptor overexpression was associated with decreased overall survival, suggesting the beneficial role of epidermal growth factor receptor inhibitors in STS. In malignant rhabdoid tumor and epithelioid sarcoma, frequent alteration of the SMARCB1/INI1tumor‐suppressor gene and the loss of its protein have been demonstrated, indicating that this molecule could be an effective target of these sarcomas. In sarcomas with epithelioid differentiation, such as synovial sarcoma and epithelioid sarcoma, overexpression of dysadherin, which downregulates E‐cadherin expression, was a poor prognostic factor. In conclusion, further studies are necessary to search for effective and specific molecules for the inhibition of tumor growth in each type of STS, especially in sarcomas without specific translocation. (Cancer Sci 2009; 100: 200–208)
Is refractory anaemia with ring sideroblasts and thrombocytosis (RARS‐T) a necessary or useful diagnostic category?
Authors: Wardrop Douglas , Steensma David P.
Published: December 2008

Both the 2001 World Health Organisation (WHO) classification of haematopoietic neoplasms and the 2008 WHO classification revision include a distinctive diagnostic category, refractory anaemia with ring sideroblasts and thrombocytosis (RARS‐T), to describe those rare patients who have both ≥15% ring sideroblasts and a sustained elevated platelet count. Recently, it has become clear that patients meeting WHO criteria for RARS‐T have clonal JAK2V617F and MPLW515 mutations at a similar rate to essential thrombocythaemia (ET). Given that the provisional classification of RARS‐T as a myelodysplastic syndrome/myeloproliferative neoplasm (MDS/MPN) overlap syndrome, rather than as a form of MPN (i.e., ET), rests principally upon the presence of ring sideroblasts, which are a non‐specific morphological finding, these new molecular results prompt reconsideration of the necessity for a distinctive RARS‐T category. Here we review the historical developments that led up the definition of RARS‐T as a disease entity, and we discuss conceptual understanding of RARS‐T and arguments against continued use of RARS‐T as a separate diagnostic category.
Clinical and histopathological characteristics of pityriasis alba
Authors: In S. I. , Yi S. W. , Kang H. Y. , Lee E. S. , Sohn S. , Kim Y. C.
Published: December 2008

Background. Pityriasis alba (PA) is a skin disorder characterized by asymptomatic, variably hypopigmented, slightly scaling patches with indistinct margins. It is sometimes difficult to clinically differentiate PA from other hypopigmented disorders such as naevus depigmentosus.

Aim. To examine the clinical and histopathological characteristics of PA that are important in differentiating PA from other hypopigmenting disorders.

Methods. A clinical survey was carried out on 56 patients with PA. Histopathological features were investigated with immunostains for NKI/beteb antibody, melanoma antigen recognized by T cells (MART)-1 and S-100 protein, and by haematoxylin and eosin and Fontana–Masson stains.

Results. Of the 56 PA patients, 10 (18%) had a previous history of atopic dermatitis and 9 (16%) had a solitary lesion. Histopathological study revealed markedly reduced pigment in the epidermis of lesional skin, but no significant difference in melanocyte count was found between lesional and normal skin. Ultrastructurally, degenerative changes in melanocytes and a reduced number of melanosomes within keratinocytes were seen.

Conclusion. No significant difference in the number of melanocytes between lesional and normal skin was seen. These findings should be considered when diagnosing and differentiating PA from other hypopigmentary disorders.
Assessment of thyroid function during the long course of Hashimoto's thyroiditis in children and adolescents
Authors: Demirbilek H. , Kandemir N. , Gonc E. N. , Ozon A. , Alikasifoglu A.
Published: December 2008

Context  The prognosis of Hashimoto's thyroiditis (HT) in children and adolescents is not well known and studies reporting long‐term outcome of the disease are scarce.

Objective  To assess the thyroid hormone status during long‐term follow‐up and to establish the prognosis of children and adolescents with HT.

Patients  One hundred and twenty‐nine patients with HT were re‐evaluated for thyroid hormone status after a mean follow‐up period of 50 months.

Results  Seventy‐seven per cent of the euthyroid patients were still euthyroid, while 21·1% of these patients became hypothyroid at the time of re‐evaluation. However, 69·5% of hypothyroid patients remained hypothyroid (overt or subclinical) and 30·5% recovered.

Conclusion  HT is a dynamic process. Thyroid functions can show variation during follow‐up. Therefore, thyroid function tests should be repeated periodically to detect progression to hypothyroidism in initially euthyroid patients as well as reversibility of hypothyroidism.
Significant tumour shrinkage after 12 months of lanreotide Autogel‐120 mg treatment given first‐line in acromegaly
Authors: Colao Annamaria , Auriemma Renata S. , Rebora Alberto , Galdiero Mariano , Resmini Eugenia , Minuto Francesco , Lombardi Gaetano , Pivonello Rosario , Ferone Diego
Published: December 2008

Objective  To evaluate GH and IGF‐I control and tumour shrinkage in newly diagnosed patients with acromegaly treated first‐line with lanreotide‐Autogel (ATG) 120 mg.

Design  Open, prospective.

Patients  Twenty‐six patients (17 women, aged 31–70 years): eight enclosed and 12 extrasellar (eight invasive) macroadenomas and six microadenomas (one invasive). ATG 120 mg initially given every 4 weeks for 12 weeks; then intervals between injections increased to every 6 or 8 weeks if GH levels were ≤ 2·5 or < 1 µg/l (equal to 6·5 and 2·6 mU/l), respectively.

Results  Final dosage was ATG 120 mg every 4 weeks in nine patients (34·6%), every 6 weeks in eight patients (30·8%) and every 8 weeks in the remaining nine patients (34·6%). After 12 months, both GH and IGF‐I were controlled in 14 patients (53·8%). The mean tumour volume decreased from 1405 ± 1827 mm3 at study entry to 960 ± 1381 mm3 after 6 months, and 799 ± 1161 mm3 after 12 months (P < 0·0001). Overall tumour shrinkage was 35·8 ± 28·1% after 6 months and 48·4 ± 27·6% after 12 months. After 12 months, 20 patients (76·9%) achieved > 25% tumour shrinkage: 12 of 14 with controlled disease (85·7%) and 8 of 12 with noncontrolled disease (66·7%; P = 0·49). Hyperhydrosis, paresthesiae and arthralgias significantly reduced after treatment. No patient withdrew from the study because of adverse events.

Conclusion  ATG 120 mg in newly diagnosed patients with acromegaly controls GH and IGF‐I secretion in 53·8% and induces ≥ 25% tumour shrinkage in 76·9% during a 12‐month period. The treatment was associated with improvement of clinical symptoms and with a good safety profile.
The effect of growth hormone treatment on metabolic and cardiovascular risk factors is similar in preterm and term short, small for gestational age children
Authors: De Kort Sandra W. K. , Willemsen Ruben H. , Van Der Kaay Danielle C. M. , Hokken‐Koelega Anita C. S.
Published: December 2008

Context  We previously reported that short, small for gestational age (SGA) children who were born preterm have a lower body fat percentage and a higher blood pressure, insulin secretion and disposition index than short SGA children born at term. Whether preterm birth also influences these parameters during GH treatment is unknown.

Objective  To compare blood pressure, insulin sensitivity, beta‐cell function and body composition during 4 years of GH treatment, between preterm and term short SGA children.

Patients  A total of 404 prepubertal non‐GH‐deficient short SGA children were divided into 143 preterm (< 36 weeks) and 261 term children.

Outcome measures  Height, blood pressure (n = 404), body composition measured by dual energy X‐ray absorptiometry (DXA) (n = 138) and insulin sensitivity and beta‐cell function calculated from a frequent sampling intravenous glucose tolerance test (FSIGT) with tolbutamide (n = 74) or from the homeostasis model assessment of insulin resistance (HOMA‐IR) (n = 204).

Results  In preterm and term children, GH treatment resulted in a similar decrease in systolic and diastolic blood pressure, body fat percentage, limb fat/total fat ratio and insulin sensitivity, and a similar increase in insulin secretion and disposition index. Lean body mass (LBM) corrected for gender and height increased in term children and did not change in preterm children. Multiple regression analysis revealed that this difference in GH effect on LBM was not associated with gestational age.

Conclusion  The effect of GH treatment on metabolic and cardiovascular risk factors is similar in preterm and term short, SGA children.