bluuebunny/crossref_metadata_2025 huggingface dataset:
Magnetospheric imaging: Promise to reality
Authors: Burch J. L.
Published: September 2005

Measurements of the plasmas, energetic particles, and electric and magnetic fields within the Earth's magnetosphere have been made with ever greater coverage and precision throughout the past 46 years; but until recently, no images of this important environment were available. However, for 2 decades or more, theoretical estimates, data from sounding rockets, and background signals from orbiting instruments designed for in situ ion measurements accumulated to show that most of the plasmas contained in the inner magnetosphere could be imaged if new instruments designed for the purpose could be placed in a suitable high‐altitude orbit. With the launch of the NASA IMAGE satellite in March 2000 the promise of magnetospheric imaging began to be realized. IMAGE provides nearly continuous imaging of the inner magnetosphere on a nominal timescale of 2 min. The discoveries made by IMAGE during its first 5 years of operation are reviewed in this paper.
Mesozoic episodic magmatism in South Korea and its tectonic implication
Authors: Sagong Hee , Kwon Sung‐Tack , Ree Jin‐Han
Published: September 2005

NE trending granitoid batholiths in South Korea are part of the huge Phanerozoic granitoid belt in east Asia. The crystallization ages of granitoid plutons show three episodes of Mesozoic magmatism in South Korea: Triassic (248–210 Ma), Jurassic (197–158 Ma), and Late Cretaceous–early Tertiary (110–50 Ma), with a Late Jurassic–Early Cretaceous (∼50 m.y.) hiatus. The granitoid ages and kinematic analyses of the Mesozoic structures in South Korea suggest that the Middle Jurassic (180–170 Ma) dextral strike‐slip ductile shear zones formed by the northwest (orthogonal) subduction of the Izanagi plate, whereas the Cretaceous sinistral faults formed by the northward (oblique) subduction of the same plate, which generally agree with proposed reconstruction of plate motions, albeit uncertain, around east Asia. Among the models proposed to explain magmatic lull in a continental arc, shallow angle subduction associated with high convergence rate and subduction of oceanic plateaus might be the probable cause for the magmatic hiatus in South Korea and Japan. The huge width (∼500 km) of the east Asian granitoid belt may be explained by oceanward retreat of subduction zone in the Cretaceous in association with change in the movement direction of the subducting plate.
Electronic spin state of ferric iron in Al‐bearing perovskite in the lower mantle
Authors: Li Li , Brodholt John P. , Stackhouse Stephen , Weidner Donald J. , Alfredsson Maria , Price G. David
Published: September 2005

We investigate the effect of pressure on the electronic spin state of ferric iron on Al‐bearing MgSiO3‐perovskite using first‐principle computations. Ferric iron (6.25 mol%) and Al (6.25 mol%) substitute for Mg and Si respectively. Five substitution models on different atomic position pairs are examined. Our results show that spin state transition from high spin (HS) to low spin (LS) occurs on the Fe3+ ions at high pressure, while there is no stability field for the intermediate spin state. Fe3+ alone can be responsible for the spin state transition. The five models witness a transition pressure ranging from 97–126 GPa. Differential stress can change the pressure for the spin collapse. The lowest pressure spin state transition occurs where Al3+ and Fe3+ are in adjacent sites. These results are one explanation to the reported experimental observations that the spin transition occurs over a wide pressure range. This finding may have important implications for the dynamics and seismic signature of the lower mantle.
A first‐principles model of spectrally resolved 5.3 μm nitric oxide emission from aurorally dosed nighttime high‐altitude terrestrial thermosphere
Authors: Duff J. W. , Dothe H. , Sharma R. D.
Published: September 2005

The spectrally resolved nighttime 5.3 μm emission from NO observed by the Cryogenic Infrared Radiance Instrumentation for Shuttle (CIRRIS‐1A) experiment aboard space shuttle Discovery at 195 km tangent altitude during a strong auroral event is modeled using a first‐principles kinetics model. An appropriate SHARC (Strategic High Altitude Radiance Code) Atmospheric Generator (SAG) is dosed with an IBC class III aurora. The spectrally resolved fundamental vibration‐rotation band emissions from NO around 5.3 μm resulting from impacts of ambient NO with O as well as reactions of N atoms with O2 are calculated under steady state conditions. The calculated results, using a local translational temperature derived from the observed spectrum, are in excellent agreement with the CIRRIS‐1A observations, validating our model. The importance of the accurate nascent vibrational and rotational distribution of chemically produced NO as well as the collisonally induced rotation‐to‐vibration relaxation of rotationally hot NO is pointed out.
Reconstruction of deglacial sea surface temperatures in the tropical Pacific from selective analysis of a fossil coral
Authors: Allison Nicola , Finch Adrian A. , Tudhope Alexander W. , Newville Matthew , Sutton Stephen R. , Ellam Robert M.
Published: September 2005

The Sr/Ca of coral skeletons demonstrates potential as an indicator of sea surface temperatures (SSTs). However, the glacial‐interglacial SST ranges predicted from Sr/Ca of fossil corals are usually higher than from other marine proxies. We observed infilling of secondary aragonite, characterised by high Sr/Ca ratios, along intraskeletal pores of a fossil coral from Papua New Guinea that grew during the penultimate deglaciation (130 ± 2 ka). Selective microanalysis of unaltered areas of the fossil coral indicates that SSTs at ∼130 ka were ≤1°C cooler than at present in contrast with bulk measurements (combining infilled and unaltered areas) which indicate a difference of 6–7°C. The analysis of unaltered areas of fossil skeletons by microprobe techniques may offer a route to more accurate reconstruction of past SSTs.
Atmospheric O2, CO2 and δ13C observations from the remote sites Jungfraujoch, Switzerland, and Puy de Dôme, France
Authors: Sturm Patrick , Leuenberger Markus , Schmidt Martina
Published: September 2005

First atmospheric O2, CO2 and δ13C flask measurements from the high altitude site Jungfraujoch (JFJ), Switzerland, as well as from the mountain site Puy de Dôme (PUY), France are presented. The four‐year records of JFJ and the three‐year records of PUY show distinct seasonal cycles and superimposed long‐term trends in the measured parameters. The mean peak‐to‐peak amplitudes of the respective seasonal cycles at JFJ are 79 per meg for O2/N2, 11 ppm for CO2, and 0.45 ‰ for δ13C. At PUY the seasonal variations are about two times larger than at JFJ. The spring time CO2 maximum at PUY appears in early march, whereas at JFJ it shows up 1 to 2 months later. The O2:CO2 correlation gives at both sites slopes of about −2 mol O2/mol CO2. Stable carbon isotope ratios of source CO2 show depleted values in wintertime and isotopically enriched values in summer.
Observations and modeling of the coupled latitude‐altitude patterns of equatorial plasma depletions
Authors: Mendillo Michael , Zesta Eftyhia , Shodhan Sheela , Sultan Peter J. , Doe Richard , Sahai Yogeshwar , Baumgardner Jeffrey
Published: September 2005

The equatorial ionosphere is host to the most dramatic and enigmatic plasma instability mechanism in the geospace environment. Equatorial spread F (ESF) was discovered in early ionosonde measurements and interpreted theoretically using Rayleigh‐Taylor theory. Subsequent diagnostic and modeling advances have improved substantially our understanding of ESF onset and evolution and its associated effects on the ionosphere throughout the low‐latitude domain. The degree to which ESF mechanisms penetrate into the lower midlatitudes is a topic of current study, a reverse of the familiar concept of high‐to‐low latitude coupling for space weather phenomena. Optical diagnostic systems, first ground based and now space based, reveal the presence of ESF structures via images of airglow depletions that are aligned in the approximately north‐south direction spanning the geomagnetic equator. Ground‐based all‐sky camera systems used to capture the two‐dimensional horizontal patterns of airglow depletions are the main source of observations showing that ESF processes intrude to midlatitudes in the L ∼ 1.5 domain. In this paper we review the process of mapping airglow depletions along geomagnetic field lines to the equatorial plane, hence defining the maximum apex heights achieved. A case study comparison of simultaneous radar backscatter data from Kwajalein with optical data from Wake Island, sites that share common magnetic meridians in the Pacific section, confirms the utility of the approach and its applicability to sites at other longitudes. Modeling studies based on buoyancy arguments using flux tube–integrated mean density values versus L shell apex heights show that instability‐induced plasma depletions starting at F layer bottomside heights easily reach altitudes above 2000 km in the equatorial plane, implying that ESF intrusions to lower midlatitudes should be a relatively frequent occurrence.
Role of canopy‐scale photochemistry in modifying biogenic‐atmosphere exchange of reactive terpene species: Results from the CELTIC field study
Authors: Stroud Craig , Makar Paul , Karl Thomas , Guenther Alex , Geron Chris , Turnipseed Andrew , Nemitz Eiko , Baker Brad , Potosnak Mark , Fuentes Jose D.
Published: September 2005

A one‐dimensional canopy model was used to quantify the impact of photochemistry in modifying biosphere‐atmosphere exchange of trace gases. Canopy escape efficiencies, defined as the fraction of emission that escapes into the well‐mixed boundary layer, were calculated for reactive terpene species. The modeled processes of emission, photochemistry, diffusive transport, and deposition were highly constrained based on intensive observations collected in a Loblolly Pine plantation at Duke Forest, North Carolina, during the CELTIC field study. Canopy top fluxes for isoprene and α,β‐pinene were not significantly altered by photochemistry as calculated escape efficiencies were greater than 0.90 for both species. β‐caryophyllene emission and photochemistry were added to the canopy model as a surrogate for the reactive sesquiterpene class of species. β‐caryopyllene escape efficiencies of 0.30 were calculated for midday summertime conditions. Urbanization scenarios were also performed to assess the impact of pollution on modifying biosphere‐atmosphere exchange. Modest changes in escape efficiencies were calculated for a wide range of anthropogenic hydrocarbon and NOx mixing ratios suggesting a simple parameterization of escape efficiency in terms of grid cell NOx may be possible for incorporating the impact of canopy scale photochemistry within biogenic emission processing systems for regional air quality and climate models. The inferred magnitude of sesquiterpene ozonolysis reactions has important implications on both daytime and nighttime radical formation in the canopy.
Deformation partitioning in flat subduction setting: Case of the Andean foreland of western Argentina (28°S–33°S)
Authors: Siame L. L. , Bellier O. , Sébrier M. , Araujo M.
Published: September 2005

The Andean foreland of western Argentina (28°S–33°S) corresponds to back arc deformations associated with the ongoing flat subduction of the Nazca plate beneath the South American lithosphere. In this paper, short‐ and long‐term tectonic regimes for this Andean region are investigated and compared to NUVEL‐1 and the new GPS‐derived velocity field for the Andes Mountains. From this comparison, it appears that (1) the slight convergence obliquity at the plate boundary is accommodated by the subduction zone itself, precluding any deformation partitioning at lithospheric scale, (2) clockwise rotation of σ1 and P axes within the Andean foreland of western Argentina suggests that Plio‐Quaternary deformation partitioning may occur in the upper plate at crustal scale, and (3) comparison of seismic rates of shallow deformations determined from moderate to large earthquakes localized between 22°S and 36°S shows that the amount of shortening is about the same (2–4 cm yr−1) between the forearcs of the 30° dipping slab segments and the back arc of the flat segment. All together, those observations are in close agreement with the idea that interplate coupling in flat subduction settings may play a key role in the present‐day transfer of plate boundary forces. Consequently, the Andean back arc of western Argentina might be regarded as an obliquely converging foreland where Plio‐Quaternary deformations are partitioned between strike‐slip and thrust motions that are localized in the east verging thin‐skinned Argentine Precordillera and west verging thick‐skinned Pampean Ranges, respectively.
Characterization of the action of S 21403 (mitiglinide) on insulin secretion and biosynthesis in normal and diabetic β‐cells
Authors: Kaiser Nurit , Nesher Rafael , Oprescu Andrei , Efendic Suad , Cerasi Erol
Published: September 2005

S 21403 (mitiglinide) is a new drug for type 2 diabetes mellitus (T2DM). Its action on insulin release and biosynthesis was investigated in several experimental systems utilizing pancreas from normal and T2DM animals.

At high concentrations (10 μM), S 21403, like classical sulphonylurea, induced insulin release in the absence of glucose. In contrast, at therapeutic (0.1–1.0 μM) concentrations, S 21403 amplified insulin secretion glucose dose‐dependently and with similar magnitude in normal and diabetic GK rat islets.

In perfused GK rat pancreas, S 21403 induced normal kinetics of insulin secretion including first‐phase response.

The effect of S 21403 was strongly modulated by physiological factors. Thus, 0.1 μM adrenaline inhibited S 21403‐induced insulin release. There was marked synergism between S 21403 and arginine in GK rat islets, combination of the two normalizing insulin secretion.

In primary islet cultures from normal rats or prediabetic Psammomys obesus, prolonged exposure to S 21403 did not induce further depletion of insulin stores under normal or ‘glucotoxic’ conditions.

Proinsulin biosynthesis was not affected by 2‐h exposure of rat or prediabetic P. obesus islets to 1 μM S 21403. Yet, 24‐h exposure of rat islets to S 21403 resulted in 30% increase in proinsulin biosynthesis at 8.3 mM glucose.

Amplification by S 21403 of glucose‐induced insulin secretion in diabetic GK β‐cells with restoration of first‐phase response, a strong synergistic interaction with arginine and marked inhibition by adrenaline, make it a prime candidate for successful oral antidiabetic agent.

British Journal of Pharmacology (2005) 146, 872–881. doi:10.1038/sj.bjp.0706374
Nanoparticle‐induced platelet aggregation and vascular thrombosis
Authors: Radomski Anna , Jurasz Paul , Alonso‐Escolano David , Drews Magdalena , Morandi Maria , Malinski Tadeusz , Radomski Marek W
Published: September 2005

Ever increasing use of engineered carbon nanoparticles in nanopharmacology for selective imaging, sensor or drug delivery systems has increased the potential for blood platelet–nanoparticle interactions.

We studied the effects of engineered and combustion‐derived carbon nanoparticles on human platelet aggregation in vitro and rat vascular thrombosis in vivo.

Multiplewall (MWNT), singlewall (SWNT) nanotubes, C60 fullerenes (C60CS) and mixed carbon nanoparticles (MCN) (0.2–300 μg ml−1) were investigated. Nanoparticles were compared with standard urban particulate matter (SRM1648, average size 1.4 μm).

Platelet function was studied using lumi aggregometry, phase‐contrast, immunofluorescence and transmission electron microscopy, flow cytometry, zymography and pharmacological inhibitors of platelet aggregation. Vascular thrombosis was induced by ferric chloride and the rate of thrombosis was measured, in the presence of carbon particles, with an ultrasonic flow probe.

Carbon particles, except C60CS, stimulated platelet aggregation (MCNSWNT>MWNT>SRM1648) and accelerated the rate of vascular thrombosis in rat carotid arteries with a similar rank order of efficacy. All particles resulted in upregulation of GPIIb/IIIa in platelets. In contrast, particles differentially affected the release of platelet granules, as well as the activity of thromboxane‐, ADP, matrix metalloproteinase‐ and protein kinase C‐dependent pathways of aggregation. Furthermore, particle‐induced aggregation was inhibited by prostacyclin and S‐nitroso‐glutathione, but not by aspirin.

Thus, some carbon nanoparticles and microparticles have the ability to activate platelets and enhance vascular thrombosis. These observations are of importance for the pharmacological use of carbon nanoparticles and pathology of urban particulate matter.

British Journal of Pharmacology (2005) 146, 882–893. doi:10.1038/sj.bjp.0706386
On the equivalence between the energy and virial routes to the equation of state of hard-sphere fluids
Authors: Santos Andrés
Published: September 2005

The energy route to the equation of state of hard-sphere fluids is ill defined since the internal energy is just that of an ideal gas, and thus it is independent of density. It is shown that this ambiguity can be avoided by considering a square-shoulder interaction and taking the limit of vanishing shoulder width. The resulting hard-sphere equation of state coincides exactly with the one obtained through the virial route. Therefore, the energy and virial routes to the equation of state of hard-sphere fluids can be considered as equivalent.
Large systems at ab initio multireference level: A cheap treatment thanks to a division into fragments
Authors: Bessac Fabienne , Hoyau Sophie , Maynau Daniel
Published: September 2005

Thanks to the use of localized orbitals and the subsequent possibility of neglecting long-range interactions, the linear-scaling methods have allowed to treat large systems at ab initio level. However, the limitation of the number of active orbitals in a complete active space self consistent-field (CASSCF) calculation remains unchanged. The method presented in this paper suggests to divide the system into fragments containing only a small number of active orbitals. Starting from a guess wave function, each orbital is optimized in its corresponding fragment, in the presence of the other fragments. Once all the fragments have been treated, a new set of orbitals is obtained. The process is iterated until convergence. At the end of the calculation, a set of active orbitals is obtained, which is close to the exact CASSCF solution, and an accurate CASSCF energy can be estimated.
Nonresonant ionization of oxygen molecules by femtosecond pulses: Plasma dynamics studied by time-resolved terahertz spectroscopy
Authors: Mics Zoltan , Kadlec Filip , Kužel Petr , Jungwirth Pavel , Bradforth Stephen E. , Apkarian V. Ara
Published: September 2005

We show that optical pump-terahertz probe spectroscopy is a direct experimental tool for exploring laser-induced ionization and plasma formation in gases. Plasma was produced in gaseous oxygen by focused amplified femtosecond pulses. The ionization mechanisms at 400- and 800-nm excitation wavelengths differ significantly being primarily of a multiphoton character in the former case and a strong-field process in the latter case. The generation of the plasma in the focal volume of the laser and its expansion on subnanosecond time scale is directly monitored through its density-dependent susceptibility. A Drude model used to evaluate the plasma densities and electron-scattering rates successfully captures the observations for a wide range of pump intensities. In addition, rotational fingerprints of molecular and ionic species were also observed in the spectra.
Does the Al13− core exist in the Al13 polyhalide Al13In−(n=1–12) clusters?
Authors: Han Young-Kyu , Jung Jaehoon
Published: September 2005

We have studied the structures and stabilities of Al13In−(n=1–12) clusters at the density-functional level of theory. Unlike the case of Al13I−, the Al13In−(n=2–12) clusters do not have an Al13− core electronically. Population analysis shows that a significant charge transfer occurs from the Al cluster to the I atoms, where the populations for Al13 vary from −0.48(Al13I2−) to +0.97(Al13I12−). Moreover, the shape of Al13 moieties in the Al13In− (n⩾6 or 7) clusters is significantly distorted from the structure of Al13−, an icosahedron, and is a “cagelike” form, which can be explained by both electronic and steric reasons. Our theoretical results are in good agreement with the experimental observations of Bergeron et al. [Science 307, 231 (2005)].
Measure of accuracy for multicanonical molecular-dynamics simulation
Authors: Shimizu Hisashi
Published: September 2005

A measure of the flatness of the energy probability distribution for multicanonical molecular-dynamics (MMD) simulation is presented. It (the flatness measure) can be introduced by a slight change in the renewing scheme of the MMD potential energy. Our proposed measure is applied to liquid Ar with a Lennard-Jones potential system in order to investigate the influence of flatness on the simulation results such as internal energy and specific heat at constant volume. We find that the accuracy of MMD simulation is influenced not only by the flatness of the energy probability distribution but also by the width of the energy region that is accessible during the MMD simulation.
Electron density and ionization dynamics in an imploding z-pinch plasma
Authors: Gregorian L. , Kroupp E. , Davara G. , Fisher V. I. , Starobinets A. , Bernshtam V. A. , Fisher A. , Maron Y.
Published: September 2005

The time-dependent radial distributions of the electron and ion densities during the implosion phase of a gas-puff z-pinch plasma are determined from measurements of continuum radiation, as well as time-dependent collisional-radiative analysis of the observed particle ionization history in the plasma. It is shown that during the 140-ns-long time interval close to the end of the ∼620-ns-long implosion phase, the total imploding-plasma mass increases by ∼65%, found to be consistent with the continuous ionization of the gas ahead of the plasma shell. Furthermore, the densities obtained, together with the previously determined radial distributions of the electron temperature, magnetic field, and particle radial velocities, are used to analyze the energy terms that support the radial propagation of the ionization wave seen in the plasma, thereby explaining the time-dependent radial distribution of the ion charge states in the plasma.
Relaxation of a quasisymmetric rotating plasma: A model of Jupiter’s magnetosphere
Authors: Shiraishi Jun-ya , Ohsaki Shuichi , Yoshida Zensho
Published: September 2005

A variational principle that uses the energy as the target functional under some constraints explains the creation of the relaxed state with a rigid-rotation flow confining a high-beta plasma. The constraints are due to the conservation of the magnetic and cross helicities, the total mechanical angular momentum, and the total magnetic flux (equivalently, the total canonical angular momentum). The constancy of the total canonical angular momentum holds when the quasiaxisymmetry of magnetic and flow fields is maintained through the relaxation process, which imposes a limitation for the dynamics leading to the creation of such a structure. The model has been applied to Jupiter’s magnetosphere.
Light-induced cell separation in a tailored optical landscape
Authors: Paterson L. , Papagiakoumou E. , Milne G. , Garcés-Chávez V. , Tatarkova S. A. , Sibbett W. , Gunn-Moore F. J. , Bryant P. E. , Riches A. C. , Dholakia K.
Published: September 2005

We demonstrate passive optical sorting of cell populations in the absence of any externally driven fluid flow. Specifically, we report the movement of erythrocytes and lymphocytes in an optical landscape, consisting of a circularly symmetric light pattern created by a Bessel light beam. These distinct cell populations move, spontaneously and differentially, across the underlying periodic optical landscape. Thus, we were able to separate lymphocytes from a mixed population of cells containing erythrocytes and then collect the lymphocytes in a microcapillary reservoir. We also demonstrate an enhanced form of this separation that exploits the polarizability of silica microspheres by attaching spheres coated with antibodies to cell surface markers to a subpopulation of lymphocytes. These techniques may be applied using standard laboratory apparatus.
Compact laser flash photolysis techniques compatible with ultrafast pump-probe setups
Authors: Schmidhammer U. , Roth S. , Riedle E. , Tishkov A. A. , Mayr H.
Published: September 2005

Two new transient absorption measurement techniques are described which use commercially available pulsed laser diodes or high-power light-emitting diodes (LEDs) as monitoring beam. The semiconductor devices substitute the probe in a kilohertz-repetition-rate ultrafast pump-probe setup. A fully functional and highly compact laser flash photolysis system reaching the nanosecond to millisecond time scale is thereby added to a state-of-the-art femtosecond system. The sample is excited with UV-Vis tunable femtosecond pulses, and for the electronically synchronized probing light either subnanosecond pulsed laser diodes for selected wavelengths or LEDs covering the visible to near infrared and UV regions are used. The applicability and reliability of the devices are demonstrated for various probe wavelengths in the visible by the investigation of excited-state decay or photoinduced bimolecular reactions. The time resolution is found to be 400 ps for the pulsed laser diodes and a few nanoseconds for the LEDs. This provides overlap to the accessible time range of the ultrafast pump-probe experiment. In this way full reaction cycles of photo-physical or -chemical processes can be monitored with identical excitation conditions.
Differential current amplification in three-terminal Y-junction carbon nanotube devices
Authors: Perkins B. R. , Wang D. P. , Soltman D. , Yin A. J. , Xu J. M. , Zaslavsky A.
Published: September 2005

We present three-terminal transistor-like operation of Y-junction carbon nanotubes with three independent contacts. Using one of the terminals as a controlling gate, differential current gain of up to 300 is observed at low temperature (4.2K) in the biasing region where the gate current is small. We present evidence that the observed transistor characteristics can be ascribed to a new amplification mechanism: gated hopping via conducting grains.
Surface-enhanced Raman scattering sensor based on D-shaped fiber
Authors: Zhang Y. , Gu C. , Schwartzberg A. M. , Zhang J. Z.
Published: September 2005

Fiber surface-enhanced Raman scattering (SERS) sensors show great potential for in vivo and in vitro detection. However, current probes based on end-polished fibers suffer from small signal due to their small active region. To overcome this, we propose and demonstrate a D-shaped fiber configuration to increase the detection area. Initial modeling has shown that most of the light can be absorbed by the SERS active layer coated on the polished fiber surface. A several orders of magnitude increase in surface area leads to substantially more detectable Raman scattered photons than those in end-tip configurations. The SERS sensor based on D-shaped fibers has been demonstrated with excellent results using rhodamine 6G.
Nanoindentation study of nanofibers
Authors: Tan E. P. S. , Lim C. T.
Published: September 2005

Nanoindentation study of a single poly(L-lactic acid) nanofiber produced by the phase separation method was performed using an atomic force microscope (AFM) cantilever tip. Issues concerning the use of AFM for nanoindentation of polymer nanofibers were discussed. The Hertz theory of contact mechanics was used to analyze the indentation results. It was found that the elastic modulus was comparable to that obtained from the nanoscale three-point bend test done in our previous study, after roughness correction was made.
Grain size estimations from the direct measurement of nucleation and growth
Authors: Lee Hoo-Jeong , Ni Hai , Wu David T. , Ramirez Ainissa G.
Published: September 2005

Microstructures that emerge during the crystallization of amorphous materials depend on nucleation and growth kinetics. The ability to predict these final microstructures, particularly the average grain size, would allow better control of material properties. Well-established crystallization theories have proposed mathematical models to describe these microstructures. What remains missing, however, is an independent experimental verification of the microstructures these models predict. Here, we report in situ transmission-electron-microscopy experimental methods that assess independently the nucleation and growth rates of crystallizing grains. A consequence of having a separate, experimentally-determined description of nucleation and growth is the ability to predict the average grain size over a broad range of temperatures. The results from these experimental methods verify the theoretical models that were posed several decades ago.
Polarization-dependent optical properties of planar photonic crystals infiltrated with liquid crystals
Authors: Schuller Ch. , Reithmaier J. P. , Zimmermann J. , Kamp M. , Forchel A. , Anand S.
Published: September 2005

Photonic crystals with infiltrated liquid crystals are investigated in the 1.5μm wavelength regime. Due to the strong temperature dependence of the refractive index of liquid crystals, especially near the clearing point, i.e., at the transition between nematic and isotropic phase, the optical properties of photonic crystals can be tuned by small temperature changes. The refractive index of liquid crystals is birefringent and, therefore, sensitive for the polarization of the incident light. By using microresonators embedded into planar photonic crystal waveguides, the polarization dependence of the optical properties with and without infiltrated liquid crystal is investigated. The experimental results quantitatively agree well with the calculated photonic band structure assuming a temperature depending reorientation of the liquid crystal director field inside the holes.
Scanning transmission electron microscopy of gate stacks with HfO2 dielectrics and TiN electrodes
Authors: Agustin Melody P. , Fonseca Leonardo R. C. , Hooker Jacob C. , Stemmer Susanne
Published: September 2005

High-angle annular dark-field (HAADF) imaging and electron energy-loss spectroscopy (EELS) in scanning transmission electron microscopy were used to investigate HfO2 gate dielectrics grown by atomic layer deposition on Si substrates, and their interfaces with TiN electrodes and silicon, as a function of annealing temperature. Annealing at high temperatures (900°C) caused significant roughening of both bottom (substrate) and top (electrode) interface. At the bottom interface, HAADF images showed clusters of Hf atoms that protruded into the interfacial SiO2 layer. Low-loss EELS established that even crystalline HfO2 films exposed to relative high temperatures (700°C) exhibited significant differences in their electronic structure relative to bulk HfO2. Further annealing caused the electronic structure to more closely resemble that of bulk HfO2, with the most significant change due to annealing with the TiN electrode.
Piezo-effect and physics of CdS-based thin-film photovoltaics
Authors: Shvydka Diana , Drayton J. , Compaan A. D. , Karpov V. G.
Published: September 2005

We report a strong reversible piezo-effect in CdTe∕CdS photovoltaics consistent with the piezo parameters of CdS. Our finding suggests a different understanding of CdS-based solar cells including CdTe- and CuIn(Ga)Se-based devices. Because the CdS film is put into compression in the device, the piezo coupling generates surface charges and the electric field opposing that of the absorber layer. The corresponding potential barrier makes CdS insulating and the device operate in a metal-insulator-semiconductor mode. Our understanding introduces the concept of piezo-photovoltaics and suggests specific practical implications.
Effect of recombinantfowlpox virusexpressing chicken interferon-γ on active immunity induced by avian influenza vaccines of H5 subtype in chickens
Authors: Li-Jun Jia , Xiu-Fan Liu , Yan-Mei Zhang , Da-Xin Peng , Ru-Kuan Zhang
Published: September 2005

To evaluate the potential adjuvant effect of chicken interferon-γ (IFN-γ) expressed by recombinantfowlpox virus(rFPV–IFN-γ), SPF chickens and commercial chickens with (MAb+) and without (MAb−) maternal antibodies were immunized with rFPV–IFN-γ plus either H5 subtype avian influenza vaccine based on recombinantfowlpox virus(rFPV–HA) or conventional inactivated vaccine. In the assay of humoral responses, rFPV–IFN-γ plus vaccines induced a slightly lower titre of haemagglutinin inhibition (HI) antibody response than either rFPV–HA or inactivated vaccine alone, in both MAb−and MAb+chickens. As for protective efficacy, the combinations of rFPV–IFN-γ and both vaccines induced 95–100% protection against lethal challenge withhighly pathogenic avian influenza virusin SPF chickens and MAb−chickens, which were equal to those induced by either vaccine alone. However, immunization of MAb+chickens with 106pfu rFPV–HA plus 105pfu rFPV–IFN-γ showed higher protection efficacy (33.5%) than that (11.4–15.8%) induced by treatments with other dosage combinations. These findings show that IFN-γ expressed by recombinantfowlpox viruscould not promote HI antibody response induced by H5 avian influenza vaccines in chickens. The results also suggest that rFPV–IFN-γ enhances the protection of chickens in a dose-dependent and immune status-dependent manner.
RNA3 nucleotide sequence analyses ofpeanut stunt virusMi strain
Authors: Ze-Yong Xu , Li-Ying Yan , Kun-Rong Chen , Prins Marcel
Published: September 2005

Nucleotide sequence of full-length cDNA ofpeanut stunt virus(PSV) Mi strain RNA3 was determined and compared with those of PSV-ER and -J (subgroup I) and PSV-W (subgroup II), strains ofcucumber mosaic virus(CMV) andtomato aspermy virus(TAV). PSV-Mi RNA3 consists of 2170 nt and has two open reading frames, encoding a putative movement protein (3a protein) and a coat protein (CP). PSV-Mi RNA3 is 77.7% and 78.5% identical to those of PSV-ER and -J, whereas it shares 76.6% identity with PSV-W. Nucleotide identity of3aandcpgenes between PSV strains Mi and ER, J and W was 78.3–79.3% and 74.4–77.8%, respectively. Amino acid identity of 3a and CP between PSV-Mi and -ER, -J and -W was 73.9–77.4% and 64.8–77.5%, respectively. RNA3 of PSV-Mi (GenBank accession no. AY775057) had a varied intercistronic and 5′-untranslated region compared with those of PSV strains ER, J and W. Results indicate that PSV-Mi represents a new PSV subgroup from China, designated as subgroup III.
Analysis of plant mRNA upstream open reading frames
Authors: Yong-Feng Jin , Hui-Qing Jin , Ping Zhou , Teng-Fei Bian
Published: September 2005

Upstream open reading frames (uORFs) in 5′-untranslated regions (5′-UTRs) of eukaryotic mRNAs play an important role in translation efficiency. Computational analysis of the upstream ATG (uATG) and uORFs of 5′-UTRs of plant mRNAs, adopted from the nucleotide sequence databank, was carried out. Statistical analysis revealed that up to 18% of 5′-UTRs contain uATG, which is much higher than the earlier estimate. Among them, about 50% of the genes have one uATG and nearly 20% of them have two uATGs. About 85% of uORFs are non-overlapping. Thirty per cent of uORF peptides comprise 1–5 aa, and about 80% of uORFs fall in the range of below 20 aa. Sequences flanking the uATG codon differ strikingly from the functional initiation codon and the uATG triplet is more frequently located in a non-optimal context. Consensus sequences of the ATG codon context of mRNA with and without uATG are similar, whereas the ATG codon context of mRNA without uATG is more frequently located in an optimal context than is mRNA with uATG. Most mRNAs with uATGs are possibly related to regulatory functions. In addition, most mRNA uORFs have no similarity between plant species whereas sequences of a few uORFs are highly conserved. For example, mRNA uORFs encoding S-adenosyl-l-methionine decarboxylase (AdoMetDC) share 75–100% homology between plant species, which is much more conserved than AdoMetDC protein.
Differentially expressed genes between chicken hybrids and their parents and relationship with heterosis
Authors: Dong-Xiao Sun , Dong Wang , Yuan Zhang , Ying Yu , Gui-Yun Xu , Jun-Ying Li
Published: September 2005

mRNA differential display was used to analyse differences of gene expression between cross combinations, EC and CE, and their parental inbreeds, White Plymouth Rock (EE) and Silkies (CC). Three genes specifically expressed and one gene over-expressed in hybrids were found. By cloning, sequencing and BLAST analysis, one specific expression cDNA band was identified as the cytosolic isocitrate dehydrogenase gene, two were new genes of unknown function, and the over-expressed one was a proteosome subunit p112 gene. The results imply that functional and regulatory genes, expressed or over-expressed in chicken hybrids, are related to heterosis of some carcass traits.
Biological invasions: the case of planorbid snails
Authors: Pointier J.P. , David P. , Jarne P.
Published: September 2005

A large number of planorbid snails are now commonly transported by man mainly through the aquatic plant trade. However, only a restricted number of species establish viable populations in a new habitat and a more restricted number spread. Only five planorbid species can be ranked in this last category and can be considered as pests because of their role in the transmission of parasites to humans or domestic animals: Biomphalaria glabrata, B. straminea, B. tenagophila, B. pfeifferi and Indoplanorbis exustus. The neotropical B. glabrata, B. straminea and B. tenagophila have proven their capacity to invade another continent sometimes creating new transmission foci. The African B. pfeifferi and the Indian I. exustus have also expanded their distribution area with long-distance dispersal. Other planorbid species, i.e. Helisoma duryi, Amerianna carinata and Gyraulus spp. have been able to establish viable populations, but not to spread, presumably because they are limited to specific habitats or/and display poor competitive abilities.
Epidemiology of fascioliasis in human endemic areas
Authors: Mas-Coma S.
Published: September 2005

Considered a secondary zoonotic disease until the mid-1990s, human fascioliasis is at present emerging or re-emerging in many countries, including increases of prevalence and intensity and geographical expansion. Research in recent years has justified the inclusion of fascioliasis in the list of important human parasitic diseases. At present, fascioliasis is a vector-borne disease presenting the widest known latitudinal, longitudinal and altitudinal distribution. Fasciola hepatica has succeeded in expanding from its European original geographical area to colonize five continents, despite theoretical restrictions related to its biology and in turn dependent upon environmental and human activities. Among the different epidemiological situations, human hypo- to hyperendemic areas, including epidemics, are noteworthy. A global analysis of the distribution of human cases shows that the expected correlation between animal and human fascioliasis only appears at a basic level. Areas presenting very high human prevalences and intensities, especially in children and females, have been recently described. In hypo- to hyperendemic areas of Central and South America, Europe, Africa and Asia, human fascioliasis presents a range of epidemiological characteristics related to a wide diversity of environments. Thus far well-known epidemiological patterns of fascioliasis may not always explain the transmission characteristics in any given area and control measures should consider the results of ecoepidemiological studies undertaken in the zones concerned.
Reviewing lymnaeid vectors of fascioliasis by ribosomal DNA sequence analyses
Authors: Bargues M.D. , Mas-Coma S.
Published: September 2005

Snails of the family Lymnaeidae are of great parasitological importance due to the numerous helminth species they transmit, mainly trematodiases (such as fascioliasis) of considerable medical and veterinary impact. The present knowledge of the genetics and host–parasite relationships of this gastropod group is far from adequate. Fascioliasis is caused by two species, Fasciola hepatica and F. gigantica, which, as in the case of other trematodes, show a marked snail host specificity. Many lymnaeid species involved in fascioliasis transmission still show a confused systematic-taxonomic status. The need for tools to distinguish and characterize species and populations of lymnaeids is evident and the present review concerns new molecular tools developed in recent years using nuclear ribosomal DNA sequences. The small subunit or 18S gene and the internal transcribed spacers ITS-2 and ITS-1 are analysed and evaluated as markers for taxon differentiation and relationships within the Lymnaeidae from genus and species levels to subspecies and population levels. rDNA sequence differences and genetic distances, and their value for reconstructing phylogenetic trees using different methods are considered. Nuclear rDNA sequences are appropriate tools on which to base a review of the systematics and taxonomy of the family Lymnaeidae, without excluding other valuable snail characteristics already available. A reconstruction of the lymnaeid system towards a more natural classification will undoubtedly be helpful in understanding parasite transmission and epidemiological features as well the dispersion of an emerging-reemerging disease such as fascioliasis. Nomenclature for nuclear rDNA genotyping in lymnaeids includes the main rDNA sequence regions able to furnish important information on interspecific differentiation and grouping as well as intraspecific variability of lymnaeid species. The composite haplotype code includes the rDNA markers arranged in order according to their well-known usefulness, in its turn related to their respective, more or less rapid evolutionary ratios, to distinguish between different taxonomic levels, from supraspecific taxa to the species level and up to the population level.
Clonorchiasis: an update
Authors: Rim H.-J.
Published: September 2005

Clonorchis sinensis, the Chinese or oriental liver fluke, is an important human parasite and is widely distributed in southern Korea, China (including Taiwan), Japan, northern Vietnam and the far eastern part of Russia. Clonorchiasis occurs in all parts of the world where there are Asian immigrants from endemic areas. The human and animal reservoir hosts (dogs, pigs, cats and rats) acquire the infection from the ingestion of raw fish containing infectious metacercariae. The first intermediate snail hosts are mainly species of Parafossarulus and Bithynia. Numerous species of freshwater fish serve as the second intermediate hosts of C. sinensis. Extensive studies of clonorchiasis during several decades in Japan, Korea, China and other countries have shown much progress in proving its morphological features including ultrastructure, biology, pathogenesis, epidemiology, clinical manifestations and chemotherapy. The present review deals with mainly current results obtained on the epidemiological, pathological and clinical aspects, as well as control measures in endemic areas. As for the complications of clonorchiasis, formation of calculi in the intrahepatic biliary passages is one of the most characteristic pathological features. It is sometimes accompanied by suppurative cholangitis, cholecystitis, cholangiohepatitis and ultimately can cause cholangiocarcinoma. Experimental results on the relationship to the occurrence of cholangiocarcinoma are presented. Clinical diagnosis by radiological findings including cholangiography, sonography and computerized tomography as well as magnetic resonance imaging for biliary or pancreatic ducts are outlined. Current studies on immunology and molecular biology of C. sinensis were introduced. Praziquantel is the drug of choice for clonorchiasis. The most effective regimen is 25 mg kg−1 three times daily (total dose, 75 mg kg−1) administered orally at 5- to 6-h intervals over a single day. Prevention and control measures are also discussed.
Towards control of schistosomiasis in sub-Saharan Africa
Authors: Southgate V.R. , Rollinson D. , Tchuenté L.A. Tchuem , Hagan P.
Published: September 2005

Approximately 80% of the 200 million people infected with schistosomiasis inhabit sub-Saharan Africa, and the annual mortality is estimated to be 280,000. Praziquantel is the drug of choice in the treatment of schistosomiasis and pregnant women may now be treated. It was agreed at the World Health Assembly in 2001 that at least 75% of school-aged children in high burden areas should be treated for schistosomiasis and soil-transmitted helminth infections by 2010 to reduce morbidity. A grant from the Bill and Melinda Gates Foundation to the Schistosomiasis Control Initiative, Imperial College of Science, Technology and Medicine, London has enabled control programmes to be initiated in Uganda, Tanzania, Zambia, Burkina Faso, Niger and Mali. Additional programmes have recently commenced in Zanzibar with a grant from the Health Foundation to The Natural History Museum, London and in Cameroon. Combination treatment for schistosomiasis, gastrointestinal helminths and filariasis reduces costs of control programmes. The EC Concerted Action Group on ‘Praziquantel: its central role in the chemotherapy of schistosome infection’ met in Yaoundé Cameroon in 2004 to discuss recent developments in laboratory and field studies. The use of standard operating procedures will enable data on drug action on schistosomes produced in different laboratories to be compared. With the ever increasing use of praziquantel there is a possibility of the development of resistance by schistosomes to the drug, hence the necessity to explore the activities of other compounds. Artemether, unlike praziquantel, is effective against immature schistosomes. The effectiveness of mirazid, an extract of myrrh, is controversial as data from different laboratories are equivocal. It is suggested that an independent body such as the World Health Organization should determine whether mirazid should be used in the treatment of schistosomiasis.