bluuebunny/crossref_metadata_2025 huggingface dataset:
MODIS chlorophyll variability in the northern Adriatic Sea and relationship with forcing parameters
Authors: Mauri Elena , Poulain Pierre‐Marie , Južnič‐Zonta Živko
Published: February 2007

The variability of the MODIS chlorophyll concentration in the northern Adriatic Sea is described between July 2002 and January 2005 and related to the Po River discharge rates and local wind forcing. After interpolation, the MODIS data were decomposed into EOF modes. Significant variability (∼61%) is explained by the first three modes in which mode 1 includes a strong seasonal cycle with enhanced signal in winter for the open sea waters and a second maximum in April–May, and mode 2 separates the coastal and river‐influenced waters, from the open sea area. The temporal amplitude of the modes is significantly correlated with the Po River runoff. The interpolated MODIS data were also correlated with the Po River discharge rates, resulting in significant positive correlation north and south of the delta and off the Croatian Islands. When correlated with wind speed, the MODIS chlorophyll shows positive correlation in the area off Istria, off Croatia and at the edge of the coastal layer north of Ancona. Using wind regimes, similar patterns are found for the Bora‐wind like winds. In contrast, for Sirocco‐like winds, the correlation is significantly positive in the vicinity and north of the Po River delta. The regions off Ancona and Istria have poor correlation with the Po and wind because the MODIS chlorophyll variability is associated with mesoscale instability features not directly related to these forcing parameters. Poor (and even slightly negative) correlations are found off the Po delta. In most areas, correlations reach maximum values after 1–2 days.
Accurate calculation of friction in tubes, channels, and oscillatory flow: A unified formulation
Authors: Giménez‐Curto Luis A. , Corniero Miguel A.
Published: February 2007

The dynamics of estuaries and coastal waters is strongly influenced by friction, which must be modeled with great accuracy in order to construct reliable hydrodynamic and morphodynamic models of these regions. We show that using appropriate global scaling (which does not depend on the detailed distribution of mean velocity and momentum) together with a single numerical coefficient, which is analytically calculated, the entire friction laws in tubes, channels, and oscillatory flow can be made to collapse into one single curve for both smooth and rough (granular type) walls. This suggests that wall friction has a global nature, which allows the derivation of a new unified expression for turbulent friction that is valid for all these flows and is noticeably more accurate than existing formulae (including Prandtl's universal law of friction for smooth pipes and subsequent refinements based on the Princeton superpipe experiment). In the light of previous work by the authors we consider finally the case of high roughness, for which simple turbulent friction laws cease to be valid, showing that observation is consistent with an upper bound for the flux of longitudinal momentum toward the wall that turbulence can generate. This leads to a new expression for the law of friction appropriate to high roughness cases which is shown to be in excellent agreement with observation.
Observed seasonal variability of barrier layer in the Bay of Bengal
Authors: Thadathil Pankajakshan , Muraleedharan P. M. , Rao R. R. , Somayajulu Y. K. , Reddy G. V. , Revichandran C.
Published: February 2007

The observed formation of barrier layer (BL) and the seasonal variability of BL thickness (BLT) in the Bay of Bengal are examined utilizing the most comprehensive data set. Thick BL (∼40 m) first appears in the coastal region of the northeastern bay in June and spreads westward as the summer monsoon progresses. Along the east coast of India the BL formation and its variability are controlled by the East India Coastal Current (EICC). Thick BL (∼50 m) appears along the east coast of India in November when the EICC flows equatorward and gets spatially organized by December. By January it weakens when the EICC reverses. The mature phase of BLT, both in amplitude (∼60 m) and in spatial extent occurs during February, when the Subtropical Anticyclonic Gyre (SAG) is well established in the bay. During both the summer and winter monsoon seasons the surface circulation and the redistribution of low saline waters show a dominant influence on the observed BLT distribution. Other processes such as Ekman pumping and propagating Rossby waves forced by the propagating Kelvin waves along the eastern boundary also contribute significantly in modulating its variability. The annual mode of BLT shows maxima during November–December, whereas the semiannual mode peaks during February–March and August–September. The peak in February–March is attributed to the interior Ekman pumping and the associated convergence in the central bay, whereas the peak during August–September is due to the westward propagating downwelling Rossby waves from the eastern boundary.
Declines in dissolved silica concentrations in western Virginia streams (1988–2003): Gypsy moth defoliation stimulates diatoms?
Authors: Grady Amy E. , Scanlon Todd M. , Galloway James N.
Published: February 2007

Dissolved silica concentrations in western Virginia streams showed a significant bias toward declines (p < 0.0001) over the time period from 1988 to 2003. Streams with the greatest declines were those that had the highest mean dissolved silica concentrations, specific to watersheds underlain by basaltic and granitic bedrock. We examined potential geochemical, hydrological, and biological factors that could account for the observed widespread declines, focusing on six core watersheds where weekly stream chemistry data were available. No relationships were evident between stream water dissolved silica concentrations and pH, a finding supported by the results from a geochemical model applied to the dominant bedrock mineralogy. Along with changes in watershed acidity, changes in precipitation and discharge were also discounted since no significant trends were observed over the study period. Analyses of two longer‐term data sets that extend back to 1979 revealed that the initiation of the dissolved silica declines coincided with the timing of a gypsy moth (Lymantria dispar) defoliation event. We develop a conceptual model centered on benthic diatoms, which are found within each of the six core watersheds but in greater abundance in the more silica‐rich streams. Gypsy moth defoliation led to greater sunlight penetration and enhanced nitrate concentrations in the streams, which could have spurred population growth and silica uptake. The model can explain why the observed declines are primarily driven by decreased concentrations during low‐flow conditions. This study illustrates lasting effects of disturbance on watershed biogeochemistry, in this case causing decadal‐scale variability in stream water dissolved silica concentrations.
Consultants
Authors: Alexander S. P. H. , Mathie A , Peters J. A.
Published: February 2007

ALEXANDER, S.P.H., MATHIE, A. & PETERS, J.A. (2007). Guide to Receptors and Channels (GRAC), 2nd edition (2007 revision). Br. J. Pharmacol., 150 (Suppl. 1), S1–S168.
Buyer's Guide
Authors: Alexander S. P. H. , Mathie A , Peters J. A.
Published: February 2007

ALEXANDER, S.P.H., MATHIE, A. & PETERS, J.A. (2007). Guide to Receptors and Channels (GRAC), 2nd edition (2007 revision). Br. J. Pharmacol., 150 (Suppl. 1), S1–S168.
Comparison of preferred orientation and stress in silver thin films on different substrates using x-ray diffraction
Authors: Zoo Yeongseok , Alford T. L.
Published: February 2007

Silver thin films were deposited on SiO2 and polyethylene naphthalate (PEN) using e-beam evaporation. X-ray diffraction techniques were used to investigate the influence of substrate morphology on the Ag film’s texture. Different modes of texture were observed in Ag thin films on SiO2 and PEN. Detailed information regarding spatial distribution of specific {hkl} planes was obtained by conducting pole figure analyses. A typical stress measurement technique for thin films, sin2ψ analysis, was performed to study how the surface morphology of the various substrates affected the stress induced during the texture evolution of the thin films. Based on the data from this study, the preferred orientation and stress of Ag thin films on SiO2 and PEN were discussed.
The effect of flash lamp annealing on Fe implanted ZnO single crystals
Authors: Potzger K. , Anwand W. , Reuther H. , Zhou Shengqiang , Talut G. , Brauer G. , Skorupa W. , Fassbender J.
Published: February 2007

The effect of flash lamp annealing applied to ZnO single crystals implanted with 3.6 at. % Fe has been studied. For intermediate light power, the implantation-induced surface defects could be annealed without creation of secondary phases within the implanted region. At the same annealing temperatures, however, ion-beam-induced open volume defects start to increase in size. Recrystallization is initiated for the highest light power applied, i.e., the ion-beam-induced lattice disorder reflected by the minimum channeling yield of Rutherford backscattering spectroscopy decreases from 76% to 46% and the open volume defects are annealed. At the same time, the Fe3+ fraction increases at the cost of the Fe2+ states. Weak ferromagnetic properties that are mainly associated with nanoparticles are induced.
Conformational analysis of lipid molecules by self-organizing maps
Authors: Murtola Teemu , Kupiainen Mikko , Falck Emma , Vattulainen Ilpo
Published: February 2007

The authors have studied the use of the self-organizing map (SOM) in the analysis of lipid conformations produced by atomic-scale molecular dynamics simulations. First, focusing on the methodological aspects, they have systematically studied how the SOM can be employed in the analysis of lipid conformations in a controlled and reliable fashion. For this purpose, they have used a previously reported 50ns atomistic molecular dynamics simulation of a 1-palmitoyl-2-linoeayl-sn-glycero-3-phosphatidylcholine (PLPC) lipid bilayer and analyzed separately the conformations of the headgroup and the glycerol regions, as well as the diunsaturated fatty acid chain. They have elucidated the effect of training parameters on the quality of the results, as well as the effect of the size of the SOM. It turns out that the main conformational states of each region in the molecule are easily distinguished together with a variety of other typical structural features. As a second topic, the authors applied the SOM to the PLPC data to demonstrate how it can be used in the analysis that goes beyond the standard methods commonly used to study the structure and dynamics of lipid membranes. Overall, the results suggest that the SOM method provides a relatively simple and robust tool for quickly gaining a qualitative understanding of the most important features of the conformations of the system, without a priori knowledge. It seems plausible that the insight given by the SOM could be applied to a variety of biomolecular systems and the design of coarse-grained models for these systems.
Intermediates in the melting transitions of aluminum nanoclusters
Authors: Poland Douglas
Published: February 2007

The author uses heat capacity data for aluminum cluster ions, Aln+, obtained in the laboratory of Breaux et al. [Phys. Rev. Lett. 94, 17340 (2005)] to determine whether or not intermediate species are present in the transition from the solidlike form of the clusters present at low temperatures to the liquidlike form present at high temperatures. He gives a general method on how to test for the presence of such intermediates and how to calculate their probabilities and thermodynamics as a function of temperature. In addition he uses energy distribution functions, using the maximum-entropy method that he developed previously, to substantiate the presence or absence of intermediates. As examples of the method he treats n=53 and n=79 clusters both of which exhibit marked maxima in the temperature dependence of their heat capacity curves, indicating strong order-disorder transitions. He find that in the melting transition n=53 clusters have no intermediates while the melting of n=79 clusters is dominated by intermediate species.
Observation of satellite signals due to scalar coupling to spin-1∕2 isotopes in solid-state nuclear magnetic resonance spectroscopy
Authors: Iuga Adriana , Iuga Dinu , Cross Albert R. , Gerken Michael , Hazendonk Paul
Published: February 2007

A method is introduced to select the signal from a spin-1∕2 nucleus I specifically bound to another spin-1∕2 nucleus S for solid-state magic angle spinning nuclear magnetic resonance (NMR) spectroscopy via correlation through the heteronuclear J coupling. This experiment is analogous to the bilinear rotation decoupling (BIRD) sequence in liquid-state NMR spectroscopy which selects for signals from H1 directly bound to C13. The spin dynamics of this modified BIRD experiment is described using the product-operator formalism, where experimental considerations such as rotor synchronization and the effect of large chemical shielding anisotropies on I and S are discussed. Two experiments are proposed that accommodate large chemical shielding anisotropies on S: (1) by stepping the inversion pulse frequency through the entire S spectral range or (2) by adiabatically inverting the S spins. Both these experiments are shown to successfully select the signal of F19 bound to Xe129 in XeF+ salts, removing the contributions from isotopomers containing non-spin-1∕2 Xe isotopes. The feasibility in obtaining isotope-selective F19 spectra of inorganic fluoride compounds is discussed, and further modifications are proposed to expand the application to other chemical systems.
Solvent density inhomogeneities and solvation free energies in supercritical diatomic fluids: A density functional approach
Authors: Husowitz B. , Talanquer V.
Published: February 2007

Density functional theory is used to explore the solvation properties of a spherical solute immersed in a supercritical diatomic fluid. The solute is modeled as a hard core Yukawa particle surrounded by a diatomic Lennard-Jones fluid represented by two fused tangent spheres using an interaction site approximation. The authors’ approach is particularly suitable for thoroughly exploring the effect of different interaction parameters, such as solute-solvent interaction strength and range, solvent-solvent long-range interactions, and particle size, on the local solvent structure and the solvation free energy under supercritical conditions. Their results indicate that the behavior of the local coordination number in homonuclear diatomic fluids follows trends similar to those reported in previous studies for monatomic fluids. The local density augmentation is particularly sensitive to changes in solute size and is affected to a lesser degree by variations in the solute-solvent interaction strength and range. The associated solvation free energies exhibit a nonmonotonous behavior as a function of density for systems with weak solute-solvent interactions. The authors’ results suggest that solute-solvent interaction anisotropies have a major influence on the nature and extent of local solvent density inhomogeneities and on the value of the solvation free energies in supercritical solutions of heteronuclear molecules.
The effect of order and dose of H and He sequential implantation on defect formation and evolution in silicon
Authors: Nguyen Phuong , Bourdelle K. K. , Maurice T. , Sousbie N. , Boussagol A. , Hebras X. , Portigliatti L. , Letertre F. , Tauzin A. , Rochat N.
Published: February 2007

In this paper we study the effect of the order and dose of H and He sequential implantation on H interaction with Si lattice defects. We use systematic infrared absorption measurements to investigate the evolution of hydrogenated point defects complexes during isothermal annealing. This analysis combined with the electron microscopy data led to the identification of the infrared absorption modes corresponding to the formation of the partially amorphized layer. The obtained results provide an important input for the optimization of the implantation conditions in order to achieve fracture in Si in the wide temperature range.
Thermal stability and electrical properties of titanium-aluminum oxide ultrathin films as high-k gate dielectric materials
Authors: Shi L. , Xia Y. D. , Xu B. , Yin J. , Liu Z. G.
Published: February 2007

As potential high-k gate dielectric material for metal-oxide-semiconductor field effect transistor, the TiO2 incorporated Al2O3 [(TiO2)x(Al2O3)1−x (TAO)] films have been prepared by pulsed laser deposition. The thermal stability and electrical properties of the TAO films annealed at different temperatures have been systematically investigated by x-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and capacitance-voltage measurements. These results show that the TAO films keep amorphous state after annealed at 900°C, and the interfacial reaction between the TAO film and silicon substrate is closely related to the deposition and postannealing temperatures. The dielectric constant of the film is about 30. For a 5nm TAO film after annealed at 400°C, the thickness between interfacial layer and the silicon substrate is only two atomic layers (about 0.6nm) and a small equivalent oxide thickness (1.2nm) is achieved. A possible explanation for interfacial interaction has been proposed. By virtue of the leakage behaviors, Schottky emission is considered as the leakage mechanism of the TAO films. The advantages and disadvantages of the high-k gate dielectric material for future metal-oxide-semiconductor transistors have been discussed, which are useful for future practical application.
Grain size effect on nanomechanical properties and deformation behavior of copper under nanoindentation test
Authors: Chang Shou-Yi , Chang Ting-Kui
Published: February 2007

The mechanical properties and deformation behaviors of copper with different grain sizes have been investigated in this study by instrumented nanoindentation. Following the Hall-Petch relation, the hardness of copper specimens increased as the grain size decreased. Dislocations were clearly observed in deformed regions around indent marks, indicating plastic deformation by dislocation formation and sliding. However, the hardness of electroless copper films with an ultrafine grain size of only 10nm dropped. Voiding at grain boundaries and triple grain junctions was observed as a consequence of grain-boundary sliding and grain rotation, which was expected as the dominant deformation mechanism resulting in the reduced hardness. The critical shear stresses for the initiation of plastic deformation in the copper specimens with large grain sizes were close to the theoretical value and comparatively much lower for electroless copper films with an ultrafine grain size.
Aspect ratio dependence of magnetoresistivity in polycrystalline bismuth microwire arrays
Authors: Hasegawa Yasuhiro , Nakano Hirofumi , Morita Hiroyuki , Kurokouchi Akio , Wada Kentarou , Komine Takashi , Nakamura Hiroaki
Published: February 2007

Magnetoresistivity measurements of polycrystalline bismuth microwire arrays having a range of different diameters and a bulk sample were performed under applied magnetic fields between 0 and 2T and temperatures from 50to300K. A thin film layer was deposited on the terminations of the microwire arrays in order to completely eliminate contact resistance. The measured resistivities were in very good agreement with those of polycrystalline bulk bismuth over the entire measured temperature range, even when the resistances had different values. The magnetoresistivities increased when a magnetic field was applied, and the rate of increase of the magnetoresistivities with applied magnetic field varied in samples having different aspect ratios. It was conjectured that this variation in the rate of increase is related to the aspect ratio. Suppression of magnetoresistivity in the microwire arrays was confirmed experimentally using bulk bismuth since the aspect ratio of the microwire arrays was much larger than that of the bulk sample. The geometrical contribution of the high aspect ratio on the magnetic effect in microwire and nanowire arrays makes it possible to enhance the thermoelectric performance of materials by suppressing the magnetoresistivity and increasing the magneto-Seebeck coefficient.
Nature of smectic A*-C* phase transitions in a series of ferroelectric liquid crystals with little smectic layer shrinkage
Authors: Bezner Samuel , Krueger Michael , Hamplová Věra , Glogarová Milada , Giesselmann Frank
Published: February 2007

The smectic layer spacing of two homologous series of ferroelectric liquid crystal compounds was characterized by small-angle x-ray diffraction and different degrees of smectic layer shrinkage on cooling from the SmA* into the SmC* phase were observed. The smectic A*-smectic C* phase transition was further studied by measuring the thermal and electric field effects on the optical tilt angle and the electric polarization. With decreasing length of the alkyl terminal chain the phase transition changes from tricritical exhibiting high layer shrinkage to a pure second-order transition with almost no layer shrinkage. This is explained by the increased one-dimensional translational order of the smectic layers, which seems to promote the “de Vries”-type [Mol. Cryst. Liq. Cryst. 41, 27 (1977)] smectic A*-C* phase transition with no or little layer shrinkage.
Electronic structure and defects of high dielectric constant gate oxide La2Hf2O7
Authors: Liu D. , Tse K. , Robertson J.
Published: February 2007

The electronic structure of the high dielectric constant oxide La2Hf2O7 and its oxygen vacancies have been calculated. The lowest conduction band is localized on Hf d states and the next is localized on Hf and La d states. The charge density on the O vacancy surrounded by 4 La ions, when in clusters, can become localized on next neighbor Hf ions. It may help create interface dipoles to modify effective work functions.
Dynamic evolution in coarse-grained molecular dynamics simulations of polyethylene melts
Authors: Depa Praveen K. , Maranas Janna K.
Published: February 2007

We test a coarse-grained model assigned based on united atom simulations of C50 polyethylene to seven chain lengths ranging from C76 to C300. The prior model accurately reproduced static and dynamic properties. For the dynamics, the coarse-grained time evolution was scaled by a constant value [t=αtCG] predictable based on the difference in intermolecular interactions. In this contribution, we show that both static and dynamic observables have continued accuracy when using the C50 coarse-grained force field for chains representing up to 300 united atoms. Pair distribution functions for the longer chain systems are unaltered, and the chain dimensions present the expected N0.5 scaling. To assess dynamic properties, we compare diffusion coefficients to experimental values and united atom simulations, assign the entanglement length using various methods, examine the applicability of the Rouse model as a function of N, and compare tube diameters extracted using a primitive path analysis to experimental values. These results show that the coarse-grained model accurately reproduces dynamic properties over a range of chain lengths, including systems that are entangled.
Role of the gold film nanostructure on the nanomechanical response of microcantilever sensors
Authors: Mertens J. , Calleja M. , Ramos D. , Tarýn A. , Tamayo J.
Published: February 2007

In this study, we have determined the relationship between the nanostructure of the gold film deposited on microcantilevers and the sensitivity and reproducibility of their static response to molecular adsorption. In order to tune the properties of the gold film, gold was deposited at different rates and thicknesses. The cantilever response to molecular adsorption was characterized by exposure of the cantilevers to mercaptohexanol in water. The morphology of the gold surface was characterized by atomic force microscopy, and the residual stress induced in the cantilevers was characterized by a profilometry technique based on the optical beam deflection method. We have found that the discontinuous morphology of the gold film for small thicknesses and low deposition rates gives rise to large values of residual tensile stress due to the formation of grain boundaries at the expense of strain energy. These cantilevers exhibit the highest sensitivity and reproducibility to molecular adsorption. However, larger thicknesses and higher deposition rates produce the coalescence of gold nanoislands via atom diffusion. This is characterized by a large relative decrease (increase) of the tensile (compressive) stress. These cantilevers exhibit small sensitivity and low reproducibility to molecular adsorption. We conclude that the control of the gold coating process is critical for the reliability of the measurements with nanomechanical sensors.
Comment on “Magnetic field effects on gas discharge plasmas” [Phys. Plasmas 13, 063511 (2006)]
Authors: Allen J. E.
Published: February 2007

N. Sternberg, V. Godyak, and D. Hoffman [Phys. Plasmas 13, 063511 (2006)] have produced a detailed paper on a cylindrical plasma column in an axial magnetic field. The authors found that the radial component of the ion velocity, on leaving the plasma region, is the ion acoustic velocity. This is, of course, the Bohm velocity, but the authors did not comment on this fact. The Bohm criterion does appear to be of general validity, however, and perhaps a greater emphasis should have been given to this result.
(In,Ga)As gated-vertical quantum dot with an Al2O3 insulator
Authors: Kita T. , Chiba D. , Ohno Y. , Ohno H.
Published: February 2007

The authors fabricated a gated-vertical (In,Ga)As quantum dot with an Al2O3 gate insulator deposited using atomic layer deposition and investigated its electrical transport properties at low temperatures. The gate voltage dependence of the dI∕dV−V characteristics shows clear Coulomb diamonds at 1.1K. The metal-insulator gate structure allowed the authors to control the number of electrons in the quantum dot from 0 to a large number estimated to be about 130.
Interdiffusion effect on strained La0.8Ba0.2MnO3 thin films by off-axis sputtering on SrTiO3 (100) substrates
Authors: Chou Hsiung , Hsu S. G. , Lin C. B. , Wu C. B.
Published: February 2007

Strained La0.8Ba0.2MnO3 thin films on SrTiO3 (100) substrate are grown by an off-axis sputtering technique. It is found that the ferromagnetic temperature TC increases for thinner films. Secondary ion mass spectroscopy indicates that Sr diffuses partially into the film, making it structurally nonuniform. The region close to the film/substrate interface acts as La1−x(SryBa1−y)xMnO3 with a near negligible y for the as grown film and a non-negligible amount of y for the high-temperature postannealed film. The enhancement of TC is attributed to the combination of the strain and interdiffusion effects.
“Plug and play” single-photon sources
Authors: Xu Xiulai , Toft Ian , Phillips Richard T. , Mar Jonathan , Hammura Kiyotaka , Williams David A.
Published: February 2007

The authors report a “plug and play” source of single photons, with full integration to a single-mode optical fiber. One end of the fiber is attached to the top of an InGaAs∕GaAs quantum dot wafer. The other end is connected via a wavelength-division multiplexing system to two separate fibers: one for carrying excitation light and the other for emitted light. A Hanbury-Brown and Twiss [Nature (London) 77, 27 (1956)] measurement was performed on the emission from single excitons recombining in the quantum dots. A second-order correlation function at zero time delay of approximately 0.01 indicates a nearly ideal source of single photons. The maximum variation of peak position over 24days is less than 0.1nm.
Spectroscopic comparison between 1200grooves∕mm ruled and holographic gratings of a flat-field spectrometer and its absolute sensitivity calibration using bremsstrahlung continuum
Authors: Chowdhuri Malay Bikas , Morita Shigeru , Goto Motoshi , Nishimura Hiroaki , Nagai Keiji , Fujioka Shinsuke
Published: February 2007

A flat-field extreme ultraviolet (EUV) spectrometer with a varied line spacing groove grating (1200grooves∕mm at grating center) has been developed to study the emission spectra from highly ionized medium Z impurities in large helical device (LHD). It covers a wavelength range of 50–500Å using a mechanically ruled grating, which was later replaced by a newly developed laminar-type holographic grating for comparative studies. Differences in spectral resolution, intensities of higher order spectra, and sensitivities of the spectrometer were studied between the two gratings by observing the emission spectra of LHD plasmas. Although the achieved resolution was alike between them, i.e., Δλ∼0.24Å at 200Å, the holographic grating was much superior in suppressing the higher order light than the ruled grating. The relative sensitivity between the two gratings was evaluated using continuum radiation from LHD plasmas. As a result, it was found that the holographic grating has a flat response in the full wavelength range, but the sensitivity of the ruled grating drops sharply below 200Å. A new technique for the absolute calibration of the EUV holographic grating spectrometer was tried by combining the continuum radiation with a branching ratio of CIV lines (3p-3s: 5800Å∕3p-2s: 312Å), and an accurate absolute sensitivity has been successfully obtained.
Microwave assisted switching in a Ni81Fe19 ellipsoid
Authors: Nembach H. T. , Martín Pimentel P. , Hermsdoerfer S. J. , Leven B. , Hillebrands B. , Demokritov S. O.
Published: February 2007

The authors demonstrate the stimulation of the magnetization switching process of a Ni81Fe19 ellipsoid, which is dominated by domain nucleation and propagation, by applying a transverse microwave field. The study of the quasistatic switching behavior under the influence of a microwave field was performed using longitudinal magneto-optic Kerr effect magnetometry. A strong reduction of the coercive field for microwave frequencies between 500 and 900MHz has been observed, which can be attributed to two different mechanisms: microwave stimulated enhancement of domain nucleation and microwave stimulated growth of the reversed domain. The authors prove that heating is not the origin of the reduction of the coercive field.
Temperature sensor using thermal transport properties in the subthreshold regime of an organic thin film transistor
Authors: Jung Soyoun , Ji Taeksoo , Varadan Vijay K.
Published: February 2007

In this letter, a temperature sensor based on an organic thin film transistor is proposed and discussed in terms of its linearity and reliability of the variation in the subthreshold drain current with temperature. The saturation mobility exhibits thermally activated hopping and temperature-deactivated behavior in different temperature ranges, but the saturation current shows very little change compared to the subthreshold current that is linearly varied with temperature from 273to453K. In addition, sensor reliability can be ensured by placing a time delay between consecutive measurements to release the charges trapped in the dielectric/semiconductor interface, the so-called bias-stress effect.
Enhanced and retarded diffusion of arsenic in silicon by point defect engineering
Authors: Kong Ning , Banerjee Sanjay K. , Kirichenko Taras A. , Anderson Steven G. H. , Foisy Mark C.
Published: February 2007

Arsenic enhanced or retarded diffusion is observed by overlapping the dopant region with, respectively, interstitial-rich and vacancy-rich regions produced by Si implants. Enhanced diffusion can be attributed to interstitial-mediated diffusion during postimplant annealing. Two possible mechanisms for diffusion retardation, interstitial-vacancy recombination and dopant clustering, are analyzed in additional experiments. The point defect engineering approach demonstrated in this letter could be applied to fabrication of n-type ultrashallow junctions.
Stress-assisted magnetic-field-induced strain in Ni–Fe–Ga–Co ferromagnetic shape memory alloys
Authors: Morito H. , Fujita A. , Oikawa K. , Ishida K. , Fukamichi K. , Kainuma R.
Published: February 2007

To obtain a large strain for Ni–Fe–Ga ferromagnetic shape memory alloys, the Curie temperature was increased by adding Co, and the magnetic-field-induced strain (MFIS) has been investigated under static stresses. The magnetocrystalline anisotropy constant K is increased by the addition of Co, and Ni49Fe18Ga27Co6 alloy gives a relatively large value of 1.15×106erg∕cm3 at 300K. From the stress-strain curves for this alloy, the twinning stress is estimated to be 8–9MPa. Consequently, the Ni49Fe18Ga27Co6 alloy exhibits a large MFIS of about 8.5% at room temperature under a static compressive stress of about 8MPa.
Stability of transparent zinc tin oxide transistors under bias stress
Authors: Görrn P. , Hölzer P. , Riedl T. , Kowalsky W. , Wang J. , Weimann T. , Hinze P. , Kipp S.
Published: February 2007

Shifts in the threshold voltage (ΔVth) of transparent zinc tin oxide (ZTO) transistors under gate bias stress are studied. The effect of composition and processing temperature on the device stability has been investigated. Based on the research, highly stable transistors with ΔVth as small as 30mV after 1000min of operation have been fabricated with a composition of [Zn]:[Sn]=36:64. As current drivers in active matrix displays their stability renders ZTO thin film transistors (TFTs) a very attractive alternative to TFTs based on established technologies.
Ultrawide band quantum dot light emitting device by postfabrication laser annealing
Authors: Chia C. K. , Chua S. J. , Dong J. R. , Teo S. L.
Published: February 2007

An ultrawide band quantum dot (QD) light emitting device (LED) with bandwidth of 360nm covering 1284–1644nm spectral range has been demonstrated by postfabrication laser-irradiation technique. The integrated light output of the QD LED was found to increase by four times after laser annealing, attributed to the improved homogeneity of the QDs and enhanced lateral electrical and optical confinements at the active region after intermixing. Large wavelength blueshift of 315nm has been obtained at the laser annealed region and an overall increase in bandwidth of 22% has been obtained in the QD LED after postfabrication laser annealing.
Evaluation of accuracy of fine needle aspiration cytology for diagnosis of canine mammary tumours: comparative features with human tumours
Authors: Cassali G. D. , Gobbi H. , Malm C. , Schmitt F. C.
Published: February 2007

Objective: The authors evaluated the accuracy of the fine needle aspiration cytology technique in the diagnosis of 77 canine mammary gland tumours using the same cytological and histological criteria currently applied to the diagnosis of human breast cancer.

Methods: The study was performed in 73 pure or mixed‐breed female dogs submitted to surgical resections of ‘mammary tumours’. All cytological smears were stained by routine May‐Grunwald–Giemsa and Papanicolaou stains.

Results: We obtained a correct cyto‐histological correlation in 52/77 cases (67.5%) when all cytopathological examinations were considered, and in 52/56 cases (92.9%) when the inconclusive cases were excluded from the analysis.

Conclusion: Our results demonstrate that, because of the similarity of the cytological findings in the human and canine mammary gland tumours, it is possible to use the same cytological criteria applied in human pathology for the diagnosis of canine mammary gland tumours.
Asymmetric interaction specificity between two sympatric termites and their fungal symbionts
Authors: DE FINE LICHT HENRIK H. , BOOMSMA JACOBUS J. , AANEN DUUR K.
Published: February 2007

Abstract 1. Fungus‐growing termites live in an obligate mutualistic symbiosis with Termitomyces fungi. The functions of the fungal symbiont have been hypothesised to differ between species and to range from highly specific roles of providing plant‐degrading enzymes complementary to termite gut enzymes, to non‐specific roles of providing protein‐rich food to the termites.

2. Termite species with unspecialised fungal symbionts are predicted to be associated with a wider range of symbionts than species with specialised symbionts. Recent DNA data have confirmed this prediction, but evidence for differences in functional specificity has been sparse and indirect.

3. Here the consequences of symbiont interaction specificity are experimentally tested by reciprocally exchanging the fungal symbionts of sympatric colonies of Macrotermes natalensis and Odontotermes badius, which were inferred to have specialised and non‐specialised symbionts respectively.

4. As expected, survival of O. badius termites on M. natalensis fungus was not significantly worse than on their own fungus, but survival of M. natalensis termites on O. badius fungus was significantly reduced.

5. This asymmetric result confirms that symbiont roles differ significantly between macrotermitine genera and indicates that symbiont transplantation experiments are a powerful tool for testing the functional details of mutualistic symbioses.
Grasshopper egg mortality mediated by oviposition tactics and fire intensity
Authors: BRANSON DAVID H. , VERMEIRE LANCE T.
Published: February 2007

Abstract 1. It is commonly assumed that arthropod species living or hibernating in the soil would not be affected by grassland fires, even though burning results in elevated surface and below‐ground soil temperatures. The importance of elevated below‐ground soil temperatures during fires on the survival of grasshopper eggs had not been examined.

2. The effects of simulated autumn grassland fires of varying intensities on below‐ground egg mortality were examined with grasshopper species laying shallow egg pods (Ageneotettix deorum) and deeper egg pods (Melanoplus sanguinipes) to test the hypothesis that exposure to heat during fires was the mechanism responsible for population reductions in A. deorum following fire.

3. Species‐specific oviposition characteristics mediated the effects of fire intensity on below‐ground egg mortality. The results indicate that fires occurring in areas with at least 3100 kg ha−1 standing crop biomass would be expected to significantly reduce populations of A. deorum, but not M. sanguinipes. No A. deorum eggs hatched in 12 of the 14 oviposition containers subjected to simulated fires approximating a standing crop biomass of 4500 kg ha−1. This is the first study to link field observations of rangeland insect populations following fire to mechanisms related to below‐ground egg mortality.
Efficacy and safety of a high purity, double virus inactivated factor VIII/von Willebrand factor concentrate (Biostate®) in patients with von Willebrand disorder requiring invasive or surgical procedures
Authors: SHORTT J. , DUNKLEY S. , RICKARD K. , BAKER R. , STREET A.
Published: February 2007

Summary.  Biostate® is a double virally inactivated, plasma derived coagulation factor VIII (FVIII)/von Willebrand factor (VWF) concentrate registered and used in Australia, New Zealand and Asia for the treatment of patients with haemophilia A. Although Biostate® has been well characterized for FVIII and VWF (ratio 1:2 respectively) and shows a similar VWF multimeric pattern to normal plasma, limited published data is available on its clinical efficacy and safety in patients with von Willebrand disorder (VWD) who require surgical procedures. We retrospectively assessed the efficacy and safety of Biostate® in all VWD patients treated at three Australian haemophilia treatment centres undergoing invasive procedures or surgery over a 29‐month period between April 2003 and September 2005. A chart review of 43 VWD patients (26 VWD type 1, 12 VWD type 2, 5 VWD type 3; 21 male, 22 female; mean age 52 years, range 19–80 years) undergoing 58 surgical procedures (24 major, 34 minor) was performed. For each procedure, data were collected on Biostate® dosage and administration, adverse reactions, haemostatic efficacy and bleeding events. Haemostatic efficacy of Biostate® was assessed as excellent in 78% or good in 22% of procedures. There were no bleeding events attributable to lack of efficacy in any patients. No adverse reactions related to the administration of Biostate® were observed. These results suggest that Biostate® is both safe and efficacious for the prevention of excessive bleeding in VWD patients undergoing surgery or invasive procedures.
Participation in health‐promoting behaviour: influences on community‐dwelling older Chinese people
Authors: Kwong Enid Wai‐yung , Kwan Alex Yui‐huen
Published: February 2007

Aim. This paper reports a study to determine the factors affecting community‐dwelling older Chinese people's health‐promoting behaviour in the domains of physical activity, healthy dietary practices and stress management, and to identify any barriers to these behaviours.

Background. Previous studies have identified factors affecting different types of health‐promoting behaviours, including perceived self‐efficacy, perceived benefits and five individual characteristics (age, sex, marital status, education and perceived health) of older non‐Chinese people. However, few studies have simultaneously taken these factors into account in examining community‐dwelling Chinese older people's health‐promoting behaviour.

Method. Individual face‐to‐face interviews were completed in 2002–2003 with a convenience sample of 896 community‐dwelling older Chinese people in Hong Kong aged between the ages of 60 and 98 (years mean 76). Participants had no apparent communication and cognition impairments. A structured interview schedule was used to collect the data.

Results. Multiple regression analysis showed that perceived self‐efficacy, perceived benefits and sex together explained 38·4% of health‐promoting behaviour among community‐dwelling older Chinese people in Hong Kong. Fatigue during and after physical activity, enjoyment of unhealthy foods and inadequate family and peer support were the most frequently reported barriers to health‐promoting behaviour.

Conclusion. When developing health promotion programmes to motivate community‐dwelling older Chinese clients to participate in health‐promoting behaviour and to minimize barriers, community nurses should include some activities to increase both the perceived self‐efficacy and perceived benefits of health‐promoting behaviour. Future studies should include more critical factors based on theories, empirical evidence and knowledge of culture with samples that are random and from more diverse community settings.
Pressure ulcers and their treatment and effects on quality of life: hospital inpatient perspectives
Authors: Spilsbury Karen , Nelson Andrea , Cullum Nicky , Iglesias Cynthia , Nixon Jane , Mason Su
Published: February 2007

Aim.  This paper reports a study exploring patients’ perceptions and experiences of the impact of a pressure ulcer and its treatment on their health and quality of life.

Background.  Pressure ulcers are a significant health problem, and their prevention and management in primary and secondary care is high on the clinical and policy agenda. However, patients’ perspectives and experiences of the impact of pressure ulcers on health and quality of life is not understood.

Method.  Qualitative semi‐structured interviews were carried out from 2002 to 2004 with a purposive sample of 23 hospital inpatients (five men, 18 women: aged 33–92 years) with a pressure ulcer (graded 2–5) at various anatomical sites and with varied reasons for hospital admission. Data were analysed thematically.

Findings.  The majority of participants (91%; n = 21) indicated that the pressure ulcer and its treatment affected their lives emotionally, mentally, physically and socially. They presented their perspectives on the causes of their pressure ulcer and descriptions of pain (experienced by 91%), appearance, smell and fluid leakage. Patients described amounts and quality of care they received, including levels of comfort of dressings and pressure relieving equipment and the timing of interventions. They were largely dependent on others to treat, manage and care for their ulcer, but indicated that the pain, discomfort and distress of pressure ulcers was not acknowledged by nursing staff. The pressure ulcers could be pivotal in preventing full recovery, were perceived to increase hospital stays and resulted in ongoing treatments.

Conclusion.  Healthcare professionals can learn from these patients’ experiences about the management of dressings, providing information (in particular about realistic time expectations for healing), providing preventative interventions and understanding the importance of comfort and positioning for patients. The study highlights the complexities of evaluating the impact of pressure ulceration.
Impact of cardiac disease on couples’ relationships
Authors: Mahrer‐Imhof Romy , Hoffmann Andreas , Froelicher Erika Sivarajan
Published: February 2007

Aim.  This paper reports a study to describe meanings that couples mutually assign to, and practices they develop, after the onset of cardiac disease and to understand the impact of the illness on the couples’ relationships in everyday life.

Background.  Patients as well as partners are affected by the onset of cardiovascular disease. Social support within intimate relationships has been shown to be important for patient survival and well‐being, and couples’ coping strategies are pivotal for well‐being and adjustment to the chronic condition in both patients with cardiovascular disease and their partners.

Method.  Twenty‐four couples participated in this phenomenological study. Data were collected during 2003. Participants were interviewed after having been hospitalized due to an acute event and having participated in a rehabilitation programme. Three in‐depth interviews were obtained for each dyad: one couple interview and two individual interviews with each partner of the dyad. Paradigm cases were sought and thematic analyses conducted.

Findings.  All couples experienced a ‘brush with death’ at the onset of heart disease, which called for changes in lifestyle. Three distinct patterns of dealing with the illness emerged. The first revealed that some couples assess the illness as a positive, transformative experience in their lives, bringing them closer together. The second showed that a proportion of couples experience the illness as a threat which imposes fear on both partners. The challenges are faced as mutual tasks and new routines are developed. The third pattern revealed couples who experience a missed opportunity to change. These couples are disenchanted about each other but return to life as usual.

Conclusions.  Nurses can use the information gained from this study to support couples in their attempts to come to terms with the illness, and can enhance their supportive role in rehabilitation efforts.