bluuebunny/crossref_metadata_2025 huggingface dataset:
Mid‐mantle layering from SKS receiver functions
Authors: Vinnik L. P. , Oreshin S. I. , Speziale S. , Weber M.
Published: December 2010

Many seismic data on mid‐mantle discontinuities are related only to subduction zones. Here we use a method that is applicable outside subduction zones. The idea is to use SKS‐to‐P converted phases that are generated in the receiver regions and can be detected in S receiver functions. In two regions (southern Africa and Western Europe) we have detected apparently the same ‘1200‐km’ discontinuity, but at a depth that varies from 1170 km (Africa) to 1240–1270 km (Europe). The S velocity contrast at this discontinuity is ∼0.1 km/s, i.e., half of the value in subduction zones. The ‘1200‐km’ discontinuity may correspond to the phase transition of SiO2 from stishovite to CaCl2 structure. The small S velocity contrast is compatible with scenarios in which small remnants of old subducted oceanic lithosphere, thermally equilibrated and partly reacted, are finely dispersed in a bulk mantle matrix.
Statistical collapse of stratiform and convective drop diameter distributions at the ground
Authors: Ignaccolo M. , De Michele C.
Published: December 2010

The probability density function of the drop diameter at the ground is investigated during stratiform and convective precipitation intervals at Darwin, Australia. We show how, after a renormalization procedure of the drop diameter, the empirical probability density functions of both types of precipitation collapse in a single curve, indicating the possible existence of an invariant distribution of the drop diameter at the ground.
Nonlinear evolution of EMIC waves in a uniform magnetic field: 1. Hybrid simulations
Authors: Omidi N. , Thorne R. M. , Bortnik J.
Published: December 2010

We employ 2.5‐D electromagnetic, hybrid simulations that treat ions kinetically via particle‐in‐cell methods and electrons as a massless fluid to study the long‐term (hours) nonlinear evolution of electromagnetic ion cyclotron waves in the presence of multiple ion species in the outer magnetosphere. The source of the instability is a small population of hot (few keV) protons, representing plasma sheet ions at L = 9 with perpendicular temperature four times the parallel. In addition to the background population of cold protons the presence of minority, cold and heavy ions such as helium are also included. Both local (homogeneous) and nonlocal (finite‐sized source region) simulations with uniform magnetic field have been carried out. In the case of a homogeneous system, parallel propagating ion cyclotron waves are generated with amplitudes of a few percent of the background magnetic field (a few nT). After about 1000 ion gyroperiods (∼4 min) the wave amplitudes decrease by about 50% and remain nearly constant thereafter. The nonlinear evolution of the waves is associated with the gyrophase bunching of the cold protons and helium ions and reduction in the temperature anisotropy of the hot protons. In addition, parallel electrostatic waves with a wavelength half of that of the ion cyclotron waves are generated. These waves are subsequently absorbed and result in parallel heating of the cold ions. Throughout the run, both cold protons and heavy ions continue to gain energy primarily in the perpendicular direction while the hot protons reach isotropy followed by cooling in both parallel and perpendicular directions. In effect, the ion cyclotron waves continue to facilitate transfer of energy from the hot to cold ions. The results of simulations with localized hot protons show the simultaneous generation of ion cyclotron waves and expansion of the source region along the magnetic field. The nonlinear evolution of the waves is found to be similar to that seen in the homogeneous runs.
Extended Eliassen‐Palm fluxes associated with the Madden‐Julian oscillation in the stratosphere
Authors: Weare Bryan C.
Published: December 2010

Links are sought between Madden‐Julian oscillation (MJO)–related variations in the troposphere and stratospheric circulation. Tropospheric variations of equatorial MJO‐filtered 200 hPa zonal winds define indices of MJO activity for two equatorial regions in the Indian and western Pacific oceans. These indices are used to define composite means of MJO‐filtered Extended Eliassen‐Palm (E‐P) fluxes for eight height levels from the upper troposphere well into the stratosphere. Evidence is presented for significant and coherent MJO departures throughout the lower stratosphere. Significant departures of the vertical component of E‐P flux flow into the lower stratosphere both in the tropics and at higher latitudes, especially over Canada. These are accompanied by horizontal flux departures in the upper troposphere and lower stratosphere from the central tropical Pacific into northern Canada. In this region, there is a divergence of Extended E‐P flux, piling up wave energy leading to the observed increased cyclonic motion. Evidence supports the hypothesis that these high‐latitude circulation variations in the stratosphere are due to a combination of two quite distinct mechanisms. In the first, poleward propagation occurs in the upper troposphere with vertical propagation at higher latitudes. In the second, upward propagation occurs in low latitudes into the lower stratosphere. This is followed by poleward propagation into higher latitudes and then farther upward propagation.
Terdiurnal tide in the extended Canadian Middle Atmospheric Model (CMAM)
Authors: Du J. , Ward W. E.
Published: December 2010

We use the extended Canadian Middle Atmosphere Model (CMAM), a general circulation model (GCM), to investigate the nature of the terdiurnal tide. Temperature and horizontal winds from a model run are analyzed to delineate the character of this tide for zonal wave numbers s = −5 to +5. Descriptions of the annual mean amplitudes, seasonal variations, and total tide superposed from the migrating and 10 nonmigrating components are provided. The amplitudes and vertical wavelengths of the various components and the total terdiurnal tide are found to depend strongly on season, latitude, and altitude. The migrating terdiurnal component maximizes at mid and high latitudes with significant amplitudes (annual mean amplitude in wind (temperature) >10 m/s (K)) in the upper mesosphere and lower thermosphere (MLT) region. Between 80 and 100 km, maximum amplitudes occur in winter in both hemispheres, whereas above 100 km, maximum amplitudes occur during solstices. For the zonal wind field, the nonmigrating terdiurnal components Te5, Te3, Te4, Tw4, and Tw5 tend to peak at >50°N/S with amplitudes between 2 and 8 m/s. The other nonmigrating components maximize in the polar regions with amplitudes of 2–10 m/s. Possible generation mechanisms (solar heating and nonlinear interactions) for the migrating terdiurnal tide in the MLT region are also examined. Correlation analysis indicates that nonlinear interactions between the migrating diurnal and semidiurnal tides are unlikely to be the source of the migrating terdiurnal tide.
Utilizing the MODIS 1.38 μm channel for cirrus cloud optical thickness retrievals: Algorithm and retrieval uncertainties
Authors: Meyer Kerry , Platnick Steven
Published: December 2010

The cloud products from the Moderate Resolution Imaging Spectroradiometers (MODIS) on Terra and Aqua have been widely used within the atmospheric research community. The retrieval algorithms, however, oftentimes have difficulty detecting and retrieving thin cirrus, due to sensitivities to surface reflectance. Conversely, the 1.38 μm channel, located within a strong water vapor absorption band, is quite useful for detecting thin cirrus clouds since the signal from the surface can be blocked or substantially attenuated by the absorption of atmospheric water vapor below cirrus. This channel, however, suffers from nonnegligible attenuation due to the water vapor located above and within the cloud layer. Here we provide details of a new technique pairing the 1.38 μm and 1.24 μm channels to estimate the above/in‐cloud water vapor attenuation and to subsequently retrieve thin cirrus optical thickness (τ) from attenuation‐corrected 1.38 μm reflectance measurements. In selected oceanic cases, this approach is found to increase cirrus retrievals by up to 38% over MOD06. For these cases, baseline 1.38 μm retrieval uncertainties are estimated to be between 15 and 20% for moderately thick cirrus (τ > 1), with the largest error source being the unknown cloud effective particle radius, which is not retrieved with the described technique. Uncertainties increase to around 90% for the thinnest clouds (τ < 0.5) where instrument and surface uncertainties dominate.
Carbon budgets of an upland blanket bog managed by prescribed fire
Authors: Clay Gareth D. , Worrall Fred , Rose Rob
Published: December 2010

This study presents the carbon budget of a blanket bog, North Pennines, UK, subject to grazing and prescribed burning for vegetation management. The budget considers both fluvial and gaseous carbon fluxes and the following uptake and release pathways: dissolved organic carbon, particulate organic carbon, excess dissolved CO2, release of methane (CH4), net ecosystem respiration of CO2, and uptake of CO2 through primary productivity. Measurements of CH4 were not directly measured as part of this study but were estimated from hydroclimatic variables measured within the study. The results show that, if management combinations were extrapolated across the catchment, then over a 3 year period, the catchment would be a net source of carbon of between 62 and 206 gC m−2 yr−1. The action of both burning and grazing was to significantly decrease the magnitude of the carbon source relative to unburnt controls. Over the study period burnt sites were a mean source of approximately 117.8 gC m−2 yr−1 compared to unburnt sites with a mean source of 156.7 gC m−2 yr−1. Even when including the loss of carbon during the vegetation combustion, there are conditions under which the long‐term loss of carbon is less than if no burning had occurred. If total combustion of vegetation occurs, provided burning occurs at cycles longer than 32 years, then less carbon is predicted to be lost than in a no‐burn scenario.
Dendritic cells enhance detection of antigen‐specific cellular immune responses by lymphocytes from rhesus macaques immunized with an HIV envelope peptide cocktail vaccine
Authors: Nehete P.N. , Gambhira R. , Nehete B.P. , Sastry K. Jagannadha
Published: December 2010

Abstract:Detection and enumeration of functional antigen‐specific T cells is important for understanding the breadth of cell‐mediated immunity to infections and experimental vaccines. We tested the utility of dendritic cells (DC), the professional antigen presenting cells, in the enzyme‐linked immunosorbent spot‐forming cell assay (ELISPOT) for efficient monitoring of antigen‐specific immunity in rhesus macaques vaccinated with an HIV envelope peptide‐cocktail. Compared with direct antigen‐specific stimulation of peripheral blood mononuclear cells, the DC‐ELISPOT protocol involving co‐culturing of macaque T cells with autologous DC pulsed with the various peptides from the vaccine cocktail yielded up to 18‐fold higher numbers of interferon‐γ producing cells without increasing the background. Importantly, use of DC in the analyses revealed immune responses in vaccinated macaques that were otherwise undetectable. Similar data were obtained when recall responses to purified protein derivative were analyzed by the DC‐ELISPOT method using blood samples from human volunteers. These data establish the importance of DC in improving detection sensitivity and eliminating false negative results, both essential for efficient monitoring of antigen‐specific cellular immune responses.
Identification of an amino acid responsible for the CD3 polymorphism in cynomolgus monkeys (Macaca fascicularis)
Authors: Uda A. , Tanabayashi K. , Mukai R. , Terao K. , Yamada A.
Published: December 2010

Abstract: The FN18 monoclonal antibody (mAb), directed to CD3 molecules, did not react with the lymphocytes of some cynomolgus monkeys (Macaca fascicularis), because of the polymorphism of the CD3ɛ chain. The epitope recognized by the FN18 mAb was successfully expressed on COS7 cells upon transfection of plasmid DNA coding for the CD3ɛ derived from T cells of a FN18 positive cynomolgus monkey. By construction and expression of plasmid DNA encoding the mutant CD3ɛ, the amino acid residue at position 67 was demonstrated to be involved in the formation of an epitope recognizable by the FN18 mAb.
CSF 5‐HIAA concentration as an early screening tool for predicting significant life history outcomes in female specific‐pathogen‐free (SPF) rhesus macaques (Macaca mulatta) maintained in captive breeding groups
Authors: Westergaard G.C. , Cleveland A. , Trenkle M.K. , Lussier I.D. , Higley J.D.
Published: December 2010

Abstract: We examined relationships among cerebrospinal fluid (CSF) concentrations of the major serotonin metabolite (5‐HIAA, 5‐hydroxyindoleacetic acid) and significant medical and behavioral outcomes for female rhesus macaques. Based on earlier findings with males we predicted that low CSF 5‐HIAA concentrations would be associated with a range of negative life history outcomes in our captive specific‐pathogen‐free (SPF) breeding colony. We found that the mean CSF 5‐HIAA concentration among animals that died over the course of the study period was significantly lower than among animals that survived. Further examination indicated an inverse relationship between CSF 5‐HIAA concentration and number of treatments for illness, further suggesting a link between serotonergic functioning and overall animal health. Examination of behavioral data indicated that individuals with low CSF 5‐HIAA concentrations were more often the targets of aggressive bouts than were individuals with high CSF 5‐HIAA concentrations. Finally, we found a positive relationship between CSF 5‐HIAA concentration and infant survivorship. These results suggest negative life history consequences of impaired serotonergic functioning in captive female rhesus macaques, and indicate that CSF 5‐HIAA concentration sampled early in life may provide a useful tool in facilitating colony management decisions concerning utilization of scarce and increasingly valuable non‐human primate resources.
Inhalation efficacy of RFI‐641 in an African green monkey model of RSV infection
Authors: Weiss W.J. , Murphy T. , Lynch M.E. , Frye J. , Buklan A. , Gray B. , Lenoy E. , Mitelman S. , O'Connell J. , Quartuccio S. , Huntley C.
Published: December 2010

Abstract: Human respiratory syncytial virus (RSV) is a major cause of acute upper and lower respiratory tract infections. RFI‐641 is a novel RSV fusion inhibitor with potent in vitro activity. In vivo efficacy of RFI was determined in an African green monkey model of RSV infection involving prophylactic and therapeutic administration by inhalation exposure. Inhalation was with an RFI‐641 nebulizer reservoir concentration of 15 mg/ml for 15 minutes (short exposure) or 2 hours (long exposure). Efficacy and RFI‐641 exposure was determined by collection of throat swabs, nasal washes and bronchial alveolar lavage (BAL) on selected days. The short‐exposure group (15 minutes) exhibited no effect on the nasal, throat or BAL samples. The throat and nasal samples for the long‐exposure group failed to show a consistent reduction in viral titers. RFI‐641 2 hours exposure‐treated monkeys showed a statistically significantly log reduction for BAL samples of 0.73–1.34 PFU/ml (P‐value 0.003) over all the sampling days. Analysis indicates that the long‐exposure group titer was lower than the control titer on day 7 and when averaged across days. The results of this study demonstrate the ability of RFI‐641 to reduce the viral load of RSV after inhalation exposure in the primate model of respiratory infection.
Accidental lodgment of an air gun pellet in the maxillary sinus of a 6‐year old girl: a case report
Authors: Mahajan Mrinalini , Shah Naseem
Published: December 2010

Abstract   –  Air gun, although considered a toy, can cause injuries ranging from trivial to very grievous. The type and severity of injuries depend on the type of air gun used, the distance at which it is fired, and the anatomic site at which the pellet hits. An interesting case involving a young girl, who was accidentally hit by an air gun pellet at a village fair, is described. The pellet penetrated the maxillary bone to be lodged in the sinus. The treatment strategy along with literature review on short‐ and long‐term complications of air gun injuries is presented.
Use of semantic technologies for the development of a dynamic trajectories generator in a Semantic Chemistry eLearning platform
Authors: Huber Richard , Hantelmann Kirsten , Todor Alexandru , Krebs Sebastian , Heese Ralf , Paschke Adrian
Published: December 2010

ChemgaPedia is a multimedia, webbased eLearning service platform that currently contains about 18.000 pages organized in 1.700 chapters covering the complete bachelor studies in chemistry and related topics of chemistry, pharmacy, and life sciences. The eLearning encyclopedia contains some 25.000 media objects and the eLearning platform provides services such as virtual and remote labs for experiments. With up to 350.000 users per month the platform is the most frequently used scientific educational service in the German spoken Internet. In this demo we show the benefit of mapping the static eLearning contents of ChemgaPedia to a Linked Data representation for Semantic Chemistry which allows for generating dynamic eLearning paths tailored to the semantic profiles of the users.
Modelling of the blood‐brain barrier transport of morphine‐3‐glucuronide studied using microdialysis in the rat: involvement of probenecid‐sensitive transport
Authors: Xie Rujia , Bouw M René , Hammarlund‐Udenaes Margareta
Published: December 2010

The objective of this study was to investigate the impact of probenecid on the blood‐brain barrier (BBB) transport of morphine‐3‐glucuronide (M3G).

Two groups of rats received an exponential infusion of M3G over 4 h to reach a target plasma concentration of 65 μMon two consecutive days. Probenecid was co‐administered in the treatment group on day 2. Microdialysis was used to estimate unbound M3G concentrations in brain extracellular fluid (ECF) and blood.In vivorecovery of M3G was calculated with retrodialysis by drug, preceding the drug administration. The BBB transport was modelled using NONMEM.

In the probenecid group, the ratio of the steady‐state concentration of unbound M3G in brain ECF to that in blood was 0.08±0.02 in the absence and 0.16±0.05 in the presence of probenecid (P=0.001). In the control group, no significant difference was found in this ratio between the 2 days (0.11±0.05 and 0.10±0.02, respectively). The process that appears to be mainly influenced by probenecid is influx clearance into the brain (0.11 μl min−1 g‐brain−1vs0.17 μl min−1 g‐brain−1, in the absencevspresence of probenecid,P<0.001). The efflux clearance was 1.15 μl min−1 g‐brain−1. The half‐life of M3G was 81±25 min in brain ECFvs22±2 min in blood (P<0.0001). Blood pharmacokinetics was not influenced by probenecid.

In conclusion, a probenecid‐sensitive transport system is involved in the transport of M3G across the BBB.

British Journal of Pharmacology(2000)131, 1784–1792; doi:10.1038/sj.bjp.0703759
New positive allosteric modulators of the metabotropic glutamate receptor 2 (mGluR2). Identification and synthesis of N-propyl-5-substituted isoquinolones
Authors: Trabanco Andrés A. , Duvey Guillaume , Cid José María , Macdonald Gregor J. , Cluzeau Philippe , Nhem Vanthea , Furnari Rocco , Behaj Nadia , Poulain Géraldine , Finn Terry , Poli Sonia , Lavreysen Hilde , Raux Alexandre , Thollon Yves , Poirier Nicolas , D'Addona David , Andrés José Ignacio , Lutjens Robert , Le Poul Emmanuel , Imogai Hassan , Rocher Jean-Philippe
Published: December 2010

N-propyl-5-substituted isoquinolones were identified as mGluR2 PAMs via high-throughput screening (HTS). Initial SAR exploration led to the identification of compound 20.
Electromagnetic effects on toroidal momentum transport
Authors: Mahmood M. Ansar , Eriksson A. , Weiland J.
Published: December 2010

A parametric study of electromagnetic effects on toroidal momentum transport has been performed. The work is based on a new version of the Weiland model where symmetry breaking toroidicity effects derived from the stress tensor have been taken into account. The model includes a self-consistent calculation of the toroidal momentum diffusivity, which contains both diagonal and off-diagonal contributions to the momentum flux. It is found that electromagnetic effects considerably increase the toroidal momentum pinch. They are sometimes strong enough to make the total toroidal momentum flux inward.
Comparison of methods to quantify interface trap densities at dielectric/III-V semiconductor interfaces
Authors: Engel-Herbert Roman , Hwang Yoontae , Stemmer Susanne
Published: December 2010

Methods to extract trap densities at high-permittivity (k) dielectric/III-V semiconductor interfaces and their distribution in the semiconductor band gap are compared. The conductance method, the Berglund intergral, the Castagné–Vapaille (high-low frequency), and Terman methods are applied to admittance measurements from metal oxide semiconductor capacitors (MOSCAPs) with high-k/In0.53Ga0.47As interfaces with different interface trap densities. The results are discussed in the context of the specifics of the In0.53Ga0.47As band structure. The influence of different conduction band approximations for determining the ideal capacitance-voltage (CV) characteristics and those of the MOSCAP parameters on the extracted interface trap density are investigated. The origins of discrepancies in the interface trap densities determined from the different methods are discussed. Commonly observed features in the CV characteristics of high-k/In0.53Ga0.47As interfaces are interpreted and guidelines are developed to obtain reliable estimates for interface trap densities and the degree of Fermi level (un)pinning for high-k/In0.53Ga0.47As interfaces.
Localized surface plasmon resonance effects by naturally occurring Chinese yam particles
Authors: Li Quanshui , Zhang Zhili , Haque Sara S. , Zhang Mingjun , Xia Lijin
Published: December 2010

In this paper, localized surface plasmon resonance (LSPR) effects by naturally occurring Chinese yam particles are observed and quantified. Chinese yam particles were found by atomic force microscope and high-speed optical dark-field microscope. The particles with diameters greater than 200 nm are found to contribute most of ultraviolet and visible absorption. LSPR effects of silver nanoparticles by the Chinese yam particles lead to the redshifts in the extinction peaks of the silver nanoparticles. The wavelength shifts are quantitatively predicted based on discrete dipole approximation of the LSPR effects, which are sensitive to the local dielectric constant changed by the Chinese yam particles. The finding may open a new avenue to detect the biological submicron particles or virus in solution.
Communication: Hilbert-space partitioning of the molecular one-electron density matrix with orthogonal projectors
Authors: Vanfleteren Diederik , Van Neck Dimitri , Bultinck Patrick , Ayers Paul W. , Waroquier Michel
Published: December 2010

A double-atom partitioning of the molecular one-electron density matrix is used to describe atoms and bonds. All calculations are performed in Hilbert space. The concept of atomic weight functions (familiar from Hirshfeld analysis of the electron density) is extended to atomic weight matrices. These are constructed to be orthogonal projection operators on atomic subspaces, which has significant advantages in the interpretation of the bond contributions. In close analogy to the iterative Hirshfeld procedure, self-consistency is built in at the level of atomic charges and occupancies. The method is applied to a test set of about 67 molecules, representing various types of chemical binding. A close correlation is observed between the atomic charges and the Hirshfeld-I atomic charges.
Kerr detection of acoustic spin transport in GaAs (110) quantum wells
Authors: Hernández-Mínguez A. , Biermann K. , Lazić S. , Hey R. , Santos P. V.
Published: December 2010

Time-resolved Kerr reflectometry (TRKR) is used to investigate the long-range transport of spins by surface acoustic waves in undoped GaAs (110) quantum wells. TRKR measurements under an applied magnetic field demonstrate the coherent precession of the optically generated electron spin during acoustic transport over several micrometers and yield information about the relaxation processes for moving spins.
High-resolution wide-field standing-wave surface plasmon resonance fluorescence microscopy with optical vortices
Authors: Tan P. S. , Yuan X.-C. , Yuan G. H. , Wang Q.
Published: December 2010

A technique for high-resolution wide-field fluorescence microscopy by using standing surface plasmon waves induced by optical vortices (OVs) is proposed, aiming at harnessing its unique dynamic properties to sequentially illuminate specimen with different phase-shifted interference excitation field. Topological charges of the OV are employed to modulate phase-shifting of the interference pattern. Numerical studies and experimental results reveal an achievement of 0.25λ optical resolution, a factor of twofold improvement compared with the standard total-internal-reflection fluorescence microscopy.
Grain size effect on the nonlinear dielectric properties of barium titanate ceramics
Authors: Curecheriu Lavinia , Buscaglia Maria Teresa , Buscaglia Vincenzo , Zhao Zhe , Mitoseriu Liliana
Published: December 2010

The nonlinear dielectric properties of dense BaTiO3 ceramics with grain size of 1 μm–90 nm were investigated. In the finest ceramics, the permittivity reduces below 1000 and a remarkable nonhysteretic linear dc-tunability [ε(E)] is obtained at high field, above 40 kV/cm. The observed behavior was explained by considering the nanostructured ceramic as a composite formed by ferroelectric grains, whose nonlinearity is reducing, and by low-permittivity nonferroelectric grain boundaries, whose volume fraction increases when decreasing the grain size. Reducing the grain size in ferroelectric dense materials is an alternative route to accomplish the application requirements: nonhysteretic tunability and permittivity below 1000.
Causes of efficiency roll-off in phosphorescent organic light emitting devices: Triplet-triplet annihilation versus triplet-polaron quenching
Authors: Song Dandan , Zhao Suling , Luo Yichun , Aziz Hany
Published: December 2010

Delayed electroluminescence measurements are used to probe and differentiate between triplet-triplet-annihilation (TTA) and triplet-polaron-quenching (TPQ) processes and their correlation with efficiency roll-off in fac-tris(2-phenylpyridine) iridium-based phosphorescent organic light emitting devices. Investigations on devices employing 4,4′-bis(9-carbazolyl)-1,1′-biphenyl (CBP) and 4,4′,4″-tris(N-carbazolyl) triphenylamine, two widely used host materials, show that the efficiency roll-off is primarily due to TPQ processes. Guest-guest TTA, on the other hand, is found to play no major role, contrary to speculations, especially at low guest concentrations. Evidence of host-host TTA in certain cases, and its possible contribution to exciton quenching in the case of devices with CBP host, is also reported.
Carrier lifetime in erbium-doped GaN waveguide emitting in 1540 nm wavelength
Authors: Wang Q. , Hui R. , Dahal R. , Lin J. Y. , Jiang H. X.
Published: December 2010

We report the characteristics of an erbium-doped GaN semiconductor waveguide amplifier grown by metal-organic chemical vapor deposition. We demonstrated that both 980 and 1480 nm optical pumping were efficient to create population inversion between the I413/2 and I415/2 energy levels. The carrier lifetime in the I413/2 energy band was measured to be approximately 1.5 ms in room temperature, which is slightly shorter than that in erbium-doped silica due to the interaction between the erbium ions and the semiconductor lattice structure. But it is significantly longer than the carrier lifetime in a typical semiconductor optical amplifier which is in the nanosecond regime.
Magnetism and clustering in Cr-doped InN
Authors: Belabbes A. , Zaoui A. , Ferhat M.
Published: December 2010

Density functional theory was applied to study the electronic and magnetic coupling of Cr-doped InN, in which magnetic configurations have been investigated. We found that the calculated ferromagnetic stabilizing energy is strongly linked to the Cr–Cr distance. The local magnetic moment of Cr is 2.3μB, and it weakly depends on the Cr–Cr distance. The coupling between the Cr d and the N p states is found to be the origin of ferromagnetism in the InCrN system. The generalized gradient approximation-1/2 correction procedure increases the polarization of InCrN, making this system a robust half-metallic ferromagnetic alloy.
Effects of alignment layer thickness on the pretilt angle of liquid crystals
Authors: Son Jong-Ho , Zin Wang-Cheol
Published: December 2010

Mixture solutions of vertical- and planar-aligning polyimide precursors were coated on bare glass. The concentrations of the solutions were varied to control the thicknesses of the films. The resulting blend films were baked to induce imidization and then rubbed. The thicknesses (t) of the blend film and of the pure vertical-alignment film affected their surface energies; the pretilt angle can be fully controlled in the range 5.5°≤Θ0≤87° by adjusting t. The surface energy of pure planar-alignment layers was independent of t.
Effects of growth temperature on photosynthetic gas exchange characteristics and hydraulic anatomy in leaves of two cold-climate Poa species
Authors: Medek Danielle E. , Evans John R. , Schortemeyer Marcus , Ball Marilyn C.
Published: December 2010

How plastic is hydraulic anatomy with growth temperature, and how does this relate to photosynthesis? These interrelationships were studied in subantarctic Poa foliosa Hook. f. and alpine Poa hothamensis Vickery grown under 7/4°C and 12/9°C day/night temperatures, reflecting summer temperatures in their respective habitats. Conduit radii were smaller in P. foliosa than in P. hothamensis, consistent with greater avoidance of freeze/thaw-induced embolism. Despite its origins in an environment with relatively little temperature variation, P. foliosa exhibited greater plasticity in hydraulic anatomy than P. hothamensis, increasing the size and density of conduits when grown under the warmer temperature regime. Both species had similar anatomical capacities for water transport when grown at 12/9°C, but stomatal conductance was lower in P. foliosa than P. hothamensis, suggesting hydraulic limitations not explained by leaf vascular anatomy. However, greater photosynthetic capacity and foliar nitrogen contents enabled P. foliosa to achieve the same assimilation rate as P. hothamensis under the 12/9°C growth conditions. Our results showed that nitrogen plays a central role in maintaining assimilation rates when constrained either by enzymatic activity at low temperatures or by hydraulic limitations at high temperatures and evaporative demands. Interspecific differences in nitrogen and water use may influence how subantarctic and alpine vegetation responds to climate warming.
Bioinformatic studies of the wheat glutaredoxin gene family and functional analysis of the ROXY1 orthologues
Authors: Ziemann Mark , Bhave Mrinal , Zachgo Sabine
Published: December 2010

CC-type glutaredoxins comprise a large land plant-specific class of oxidoreductases. Previous research shows roles for two such proteins in developmental processes in Arabidopsis; ROXY1 mediates petal initiation and morphogenesis, and ROXY1 and ROXY2 are required for normal anther development. In the present work, the broader glutaredoxin family was investigated in hexaploid wheat with bioinformatic methods, revealing a large and multifunctional gene family. With a PCR based method, three wheat ROXY homeoalleles were isolated. Complementation analyses show that these three isoforms fully complemented the roxy1 mutation in Arabidopsis. Further, yeast two-hybrid experiments demonstrate that one such wheat ROXY protein interacts strongly with TGA3, an Arabidopsis TGA transcription factor previously shown to associate with ROXY1. Deletion analyses show that TaROXY-α3 docks to a glutamine rich region of TGA3, a putative transcriptional activation domain. These results suggest a conserved molecular role of Arabidopsis and wheat ROXY proteins in inflorescence/spike development, most likely in the post-translational regulation of TGA proteins including HBP-1b (the wheat PERIANTHIA orthologue), which likely exerts also a developmental function by activating histone gene transcription in highly proliferating tissues such as the SAM and root tip.
An economic decision model of wild rabbit Oryctolagus cuniculus control to conserve Australian native vegetation
Authors: Cooke Brian , Jones Randall , Gong Wendy
Published: December 2010

Context Economic decision models are seldom used in developing policies for the cost-effective control of invasive species that threaten natural ecosystems. However, their potential value is shown using an example of European rabbits damaging native vegetation in Australia. Aims To better define the problem of rabbit damage, provide a sound theoretical basis for implementing cost-efficient strategies for rabbit control and show how resources available for ecosystem protection can be most effectively applied. Methods A dynamic economic decision model was developed, incorporating the costs and effectiveness of three methods for controlling rabbits among native vegetation to consider alternative management strategies. A monetary value on native vegetation was set using the ‘avoided’ cost of replanting trees on roadsides and from field data we described how capacity of plant communities to regenerate improves if rabbit numbers are reduced. Key results Model outputs indicated the best combinations of methods for cost-effective rabbit control and showed how the highest benefits could be gained in protecting natural vegetation. Conclusions The model provided a framework for deciding how limited resources might be used to greatest benefit for protecting native vegetation. Implications This methodology could apply to other invasive species, provided that natural assets can be given a justifiable monetary value, control costs and effectiveness can be determined and the impact of the pests on assets can be modelled as dynamic population processes.
Shackling the digital economy means less for everyone: the impact on the music industry
Authors: Andersen Birgitte
Published: December 2010

Birgitte Andersen is Professor of the Economics and Management of Innovation in the School of Business, Economics and Informatics at Birkbeck College, University of London. She works on business innovation and technology policy, services dynamics and productivity, and the economics and management of intellectual property rights. She is a keen advocate of less exclusive intellectual property rights, and a smoother functioning of the market for intellectual property.

This proposition paper debates the policy measures designed to curb P2P file sharing on the Internet. In doing this, the paper challenges the Digital Economy Act, which passed through the UK Parliament on 8 April, and entered into force on 12 June 2010.
Copyright policy, innovation, and the limits to our understanding – a response to Birgitte Andersen’s ‘Shackling the digital economy means less for everyone’
Authors: Handke Christian
Published: December 2010

Christian Handke is assistant professor of Cultural Economics in the Department for the Study of the Arts and Culture at Erasmus University and Visiting Research Fellow with the Centre for Intellectual Property Policy & Management, Bournemouth University.
Why does the train stop halfway? The destiny should be cultural democracy
Authors: Smiers Joost
Published: December 2010

Joost Smiers is professor emeritus of Political Science of the Arts, research fellow in the Research Group Arts and Economics at the Utrecht School of the Arts in the Netherlands. He works on decision‐making in cultural matters worldwide, on new visions on copyright and the public domain, on freedom of expression versus responsibility, on cultural competition policy, on the income of artists and their entrepreneurs, on European cultural policy, on UNESCO’s Convention on Cultural Diversity, and on cultural identities.
Response to paper by Birgitte Andersen on the Digital Economy Act
Authors: Heaney Andrew
Published: December 2010

Andrew Heaney has been executive director of strategy and regulation with TalkTalk since 2007. He was previously a competition policy director with Ofcom and a partner with Spectrum Strategy Consultants.
The Digital Economy Bill and the UK’s creative industries: a perspective from China
Authors: Montgomery Lucy
Published: December 2010

Lucy Montgomery is a Research Fellow in the Centre for Creative Industries and Innovation at Queensland Institute for Technology in Brisbane. Her current work explores evolutionary approaches to understanding the role of copyright in creative innovation in China, Indonesia and Indigenous Australia. She is the author of China’s Creative Industries: Copyright, Social Network Markets and the Business of Culture in a Digital Age (2010, Edward Elgar, Cheltenham), from which some of this response is drawn.
Aiming at copyright infringers and hitting the digital economy
Authors: Dutton William H.
Published: December 2010

Bill Dutton is director of the Oxford Internet Institute. He is also Professor of Internet Studies in the University of Oxford, and fellow of Balliol College.
The role of technology in intelligence practice: linking the developer and the user perspectives
Authors: Resnyansky Lucy
Published: December 2010

Technology has penetrated the social fabric of security practices so deeply that it is often used without much reflection on its role, significance and implications. This naturalisation of technology makes it difficult for practitioners to develop their own vision of technology. They may become subject to the coercive power of technology, and appropriate the narrow technological paradigm embodied in their tools. This, in turn, makes it difficult for technology developers to understand practitioner needs and to assess the transformative potential of technology. This paper aims to develop a conceptual framework for understanding the role of technology in intelligence. The focus is on the technological capabilities supporting an analysis of sociocultural processes related to so‐called ‘new threats’. The two main problems in intelligence nowadays are deciding what data are relevant and how they should be analysed. The major issue is not the collection of information, but turning information into knowledge and action. Accordingly, the practitioner thinking about technological tools can be usefully informed by the concept of technology as a mediator between areas of knowledge production and consumption. This concept highlights technology’s ability to affect intelligence analysts’ understanding of threats, identification of data sources and information gaps, and their interaction with colleagues and consumers of intelligence products.
Microstructure and property evolution of isotropic and anisotropic NdFeB magnets fabricated from nanocrystalline ribbons by spark plasma sintering and hot deformation
Authors: Liu Z W , Huang H Y , Gao X X , Yu H Y , Zhong X C , Zhu J , Zeng D C
Published: December 2010

Isotropic and anisotropic NdFeB magnets were synthesized by spark plasma sintering (SPS) and SPS+HD (hot deformation), respectively, using melt-spun ribbons as the starting materials. Spark plasma sintered magnets sintered at low temperatures (<700 °C) almost maintained the uniform fine grain structure inherited from rapid quenching. At higher temperatures, due to the local high-temperature field caused by the spark plasma discharge, the grain growth occurred at the initial particle surfaces and the coarse grain zones formed in the vicinity of the particle boundaries. Since the interior of the particles maintained the fine grain structure, a distinct two-zone structure was formed in the spark plasma sintered magnets. The SPS temperature and pressure have important effects on the widths of coarse and fine grain zones, as well as the grain sizes in two zones. The changes in grain structure led to variations in the magnetic properties. By employing low SPS temperature and high pressure, high-density magnets with negligible coarse grain zone and an excellent combination of magnetic properties can be obtained. An anisotropic magnet with a maximum energy product of ∼30 MG Oe was produced by the SPS+HD process. HD at 750 °C did not lead to obvious grain growth and the two-zone structure still existed in the hot deformed magnets. Intergranular exchange coupling was demonstrated in the spark plasma sintered magnets and was enhanced by the HD process, which reduced the coercivity. Good temperature stability was manifested by low temperature coefficients of remanence and coercivity. The results indicated that nanocrystalline NdFeB magnets without significant grain growth and with excellent properties could be obtained by SPS and HD processes.
Polarity orientation of microtubules and its applications with motor proteins
Authors: Yokokawa Ryuji
Published: December 2010

We have studied integrations of micro/nano machining (MEMS/NEMS) technologies and biomaterials. One of our research directions is to utilize biomaterials in MEMS/NEMS to reveal new functions that could not be achieved by MEMS/NEMS alone. Here a motor protein system will be introduced as a nano actuator. The motility of kinesin and dynein motor proteins has been integrated with MEMS/NEMS or a microfluidic system. Since these motor proteins move on cytoskeletal filaments—microtubules (MTs)—depending on MT polarity, a key technology is to develop methods to orient MT polarities and then immobilize them. We have developed three methods to define MT polarities by (i) shared flow in a microfluidic channel, (ii) nanostructures and (iii) MEMS tweezers. Once MT polarities were oriented and fixed on a chip, they were ready to serve as rails for nano transport by kinesin and dynein motility. The motility was visualized by attaching cargos to motors, where the cargos were microbeads, silicon structures and quantum dots (Q-dots). This nano transport system can achieve a transport distance of up to ∼100 μm, which enables us to focus on the transport of molecules not on bulk molecular flow by conventional microfluidics. Such a bio-hybrid system will be a key factor in realizing nano-scale system integration at the molecular scale.
Cardiobacterium valvarum infective endocarditis and phenotypic/molecular characterization of 11 Cardiobacterium species strains
Authors: Chen Ming , Kemp Michael , Bruun Niels E. , Bangsborg Jette M. , Højlyng Niels , Hesselbjerg Annemarie , Dargis Rimtas , Christensen Jens Jørgen
Published: December 2010

Cardiobacterium valvarum is a newly recognized human pathogen related to infective endocarditis. Cardiobacterium species are, however, only rarely the aetiology of infective endocarditis. An infective endocarditis case is presented and, additionally, phenotypic and phylogenetic comparison of a further 10 collection strains, representing the two species within the genus, was performed. C. valvarum was isolated from the blood and DNA was present in valvular tissue (partial 16S rRNA gene analysis) from a 64-year-old man with infective endocarditis of the mitral valve, rupture of chordae and prolapse of pulmonary valves in addition to a fluttering excrescence. A mechanical mitral valve and neochordae were inserted successfully. Phenotypically, the two species within the genus Cardiobacterium resemble each other greatly. When using the Vitek 2 Neisseria–Haemophilus identification card, the reaction for phenylphosphonate was positive for all Cardiobacterium hominis strains, but negative for all C. valvarum strains, thereby separating the two species. The two species made up two separate clusters by phylogenetic examination using 16S rRNA gene sequence analysis.
Replication patterns and organization of replication forks in Vibrio cholerae
Authors: Stokke Caroline , Waldminghaus Torsten , Skarstad Kirsten
Published: December 2010

We have investigated the replication patterns of the two chromosomes of the bacterium Vibrio cholerae grown in four different media. By combining flow cytometry and quantitative real-time PCR with computer simulations, we show that in rich media, V. cholerae cells grow with overlapping replication cycles of both the large chromosome (ChrI) and the small chromosome (ChrII). In Luria–Bertani (LB) medium, initiation occurs at four copies of the ChrI origin and two copies of the ChrII origin. Replication of ChrII was found to occur at the end of the ChrI replication period in all four growth conditions. Novel cell-sorting experiments with marker frequency analysis support these conclusions. Incubation with protein synthesis inhibitors indicated that the potential for initiation of replication of ChrII was present at the same time as that of ChrI, but was actively delayed until much of ChrI was replicated. Investigations of the localization of SeqA bound to new DNA at replication forks indicated that the forks were co-localized in pairs when cells grew without overlapping replication cycles and in higher-order structures during more rapid growth. The increased degree of fork organization during rapid growth may be a means by which correct segregation of daughter molecules is facilitated.
Assessment of salinity-induced photorespiratory glycolate metabolism in Anabaena sp. PCC 7120
Authors: Srivastava Ashish Kumar , Alexova Ralitza , Jeon Young Jae , Kohli Gurjeet S. , Neilan Brett A.
Published: December 2010

This paper reports an investigation of salinity-induced glycolate metabolism in the cyanobacterium Anabaena sp. PCC 7120 (hereafter Anabaena PCC 7120). Quantitative analysis of transcripts for the photosynthesis-associated genes encoding ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco), phosphoribulokinase and transketolase, as well as those involved in glycolate metabolism (phosphoglycolate phosphatase, glycolate oxidase, alanine-glyoxylate aminotransferase and serine hydroxymethyltransferase) was performed. The expression of all investigated photosynthesis-associated genes except Rubisco was downregulated after 24 h NaCl treatment. However, under the same conditions, the transcripts encoding enzymes involved in glycolate metabolism were overexpressed. This was further confirmed by the quantitative analysis of the intermediates involved in glycolate metabolism. The intracellular levels of organic acids (glyceric, glycolic and glyoxylic acids) and amino acids (glycine and serine) were elevated in salt-treated cells as compared to those in the control cells. Transcriptional inhibition of photosynthesis-associated genes, and upregulation of genes and enhanced synthesis of intermediates associated with glycolate metabolism, indicate the occurrence of this photorespiratory metabolic pathway metabolism in Anabaena PCC 7120 under salt stress.