bluuebunny/crossref_metadata_2025 huggingface dataset:
The Trouble with Ambivalent Emotions
Authors: Kristjánsson Kristján
Published: September 2010

Mixed or ambivalent emotions have long intrigued philosophers. I dissect various putative cases of emotional ambivalence and conclude that the alleged ‘psychological problem’ surrounding them admits of a solution. That problem has, however, often been conflated with a ‘moral problem’ – of how one should react morally to such ambivalence – which remains active even after the psychological one has been solved. I discuss how the moral problem hits hardest at virtue ethics, old and new. I distinguish between particularist and generalist (Aristotelian) virtue ethics, and pay special attention to the latter. After discussing critically previous attempts at an Aristotelian solution of the ‘moral problem’ by McDowell, Stark and Carr, I pay special attention to the role ofphronesisas a second-order meta-emotion and mediator, and consider how that may offer a way out of the impasse. I finally present some concluding remarks about the idea of a constructive dividedness of mind.
Equivocating the Ad Hominem
Authors: Putman Daniel
Published: September 2010

Christopher Johnson argued in ‘Reconsidering the Ad Hominem’ that, in certain exceptional cases, appealing to ad hominem considerations is logically justifiable. My argument is that ad hominem considerations are no different than other evidential considerations. The evidential links may be strong, weak or nonexistent but there is nothing special in itself about considering ad hominem factors when weighing evidence. Like all the informal fallacies, simply because a claim has the signature of being ‘ad hominem’ does not make it irrelevant. The apparent originality of Johnson's point lies in equivocating ‘ad hominem fallacy’ with ‘ad hominem considerations’. It is not looking to personal characteristics or situations that in itself is illogical. It is when those features have no evidential link to the point at hand.
The epidemiology of rubella in Mexico: seasonality, stochasticity and regional variation
Authors: METCALF C. J. E. , BJØRNSTAD O. N. , FERRARI M. J. , KLEPAC P. , BHARTI N. , LOPEZ-GATELL H. , GRENFELL B. T.
Published: September 2010

The factors underlying the temporal dynamics of rubella outside of Europe and North America are not well known. Here we used 20 years of incidence reports from Mexico to identify variation in seasonal forcing and magnitude of transmission across the country and to explore determinants of inter-annual variability in epidemic magnitude in rubella. We found considerable regional variation in both magnitude of transmission and amplitude of seasonal variation in transmission. Several lines of evidence pointed to stochastic dynamics as an important driver of multi-annual cycles. Since average age of infection increased with the relative importance of stochastic dynamics, this conclusion has implications for the burden of congenital rubella syndrome. We discuss factors underlying regional variation, and implications of the importance of stochasticity for vaccination implementation.
How do Antarctic notothenioid fishes cope with internal ice? A novel function for antifreeze glycoproteins
Authors: Evans Clive W. , Gubala Vladimir , Nooney Robert , Williams David E. , Brimble Margaret A. , Devries Arthur L.
Published: September 2010

Antarctic fishes survive freezing through the secretion of antifreeze glycoproteins (AFGPs), which bind to ice crystals to inhibit their growth. This mode of action implies that ice crystals must be present internally for AFGPs to function. The entry and internal accumulation of ice is likely to be lethal, however, so how do fishes survive in its presence? We propose a novel function for the interaction between internal ice and AFGPs, namely the promotion of ice uptake by splenic phagocytes. We show here that i) external mucus of Antarctic notothenioids contains AFGPs and thus has a potential protective role against ice entry, ii) AFGPs are distributed widely through the extracellular space ensuring that they are likely to come into immediate contact with ice that penetrates their protective barriers, and iii) using AFGP-coated nanoparticles as a proxy for AFGP adsorbed onto ice, we suggest that internal ice crystals are removed from the circulation through phagocytosis, primarily in the spleen. We argue that intracellular sequestration in the spleen minimizes the risks associated with circulating ice and enables the fish to store the ice until it can be dealt with at a later date, possibly by melting during a seasonal warming event.
Feeding stem–leaf–pod explants of pea (Pisum sativum L.) with d-chiro-inositol or d-pinitol modifies composition of α-d-galactosides in developing seeds
Authors: Lahuta Lesław B. , Święcicki Wojciech , Dzik Tomasz , Górecki Ryszard J. , Horbowicz Marcin
Published: September 2010

Feeding stem–leaf–pod explants with d-chiro-inositol and d-pinitol was used as a method to modify α-d-galactosides in developing pea (Pisum sativum) seeds. Four genotypes differing in the composition of raffinose, stachyose and verbascose (raffinose family oligosaccharides or RFOs) in seeds – high RFOs (cv. Tiny), low RFOs (SZD175) and low verbascose (cv. Hubal and cv. Wt 506) – were studied. Although seeds of all examined pea lines were able to take up both d-chiro-inositol and d-pinitol, only d-chiro-inositol was effectively converted into its galactosides: mainly fagopyritol B1 (O-α-d-galactopyranosyl-(1 → 2)-d-chiro-inositol) and fagopyritol B2 (O-α-d-galactopyranosyl-(1 → 6)-O-α-d-galactopyranosyl-(1 → 2)-d-chiro-inositol). In seeds of pea lines naturally containing low levels of verbascose (cv. Hubal) and low RFOs (SZD175), the enhanced accumulation of fagopyritols depressed the RFO level by c. 64 and 20%, respectively. Moreover, in both genotypes, about 25 and 30% of total galactose bound in α-d-galactosides occurred in fagopyritols. d-Pinitol present in the pea seeds was converted into monogalactosides, but their accumulation was several-fold lower than that of fagopyritols and did not significantly influence the accumulation of RFOs. Pea seeds with the composition of soluble carbohydrates modified by feeding with either of the cyclitols were able to complete germination.
Impact of group-based dietary education on the dietary habits of female adolescents: a cluster randomized trial
Authors: Yamaoka Kazue , Watanabe Mariko , Hida Eisuke , Tango Toshiro
Published: September 2010

Objective

The number of extremely thin young women has increased and education at school on maintaining an optimal weight has become important. The aim of the present study was to assess the effectiveness of a group-based home-collaborative dietary education (HCDE) programme to maintain appropriate dietary intake compared to conventional school classroom education.

Design

Two-arm cluster randomized controlled trial. Twelve classes were randomly assigned as clusters to either the HCDE group or the control group. Each participant in the HCDE group received twelve sessions of group counselling aimed at increasing energy intake at breakfast by modifying dietary intake and adopting appropriate habits. The hypothesis underlying the study was that after 6 months of HCDE the total energy intake would be increased by 627 kJ from baseline (primary endpoint). Secondary outcomes were differences in intake of various nutrients from baseline. Outcome measures after log transformation were examined by t tests and linear mixed models (crude and baseline-adjusted).

Setting

Young women among Japanese female adolescents in Tokyo.

Subjects

Four hundred and seventy-four participants aged 13–15 years.

Results

Students in twelve classes were used for analysis (n 459). Energy intake was decreased in many of the classes during the 6-month period, especially for those in the control group. After adjustment for the baseline value, significant increases in energy intake and protein, calcium, magnesium and iron intakes at breakfast were observed (P < 0·05)

Conclusions

Although energy intake was increased in the HCDE group compared to the control group, further study of the HCDE is warranted.
An adapted filament model for accurate modeling of printed coplanar lines with significant surface roughness and proximity effects
Authors: Curran Brian , Ndip Ivan , Werner Christian , Ruttkowski Veronika , Maiwald Marcus , Wolf Heinrich , Zoellmer Volker , Domann Gerhard , Guttovski Stephan , Gieser Horst , Reichl Herbert
Published: September 2010

New technologies have resulted in transmission lines that deviate significantly from the intended rectangular cross sections. Trapezoidal cross sections and roughness that penetrate a significant depth into the surface in comparison to the skin-depth of the conductor can cause a very significant deviation in transmission line parameters from predicted values. Proximity effect further complicates the analysis by increasing losses and changing the impact of surface roughness by changing the current distribution. A skin-effect filament model that combines a traditional skin-effect filament modeling concept with traditional surface roughness modeling concepts is presented that accounts for surface roughness effects and non-ideal cross sections. The new technique models the transmission line non-idealities in a combined way with the current density in the signal and return current paths. This adapted filament model shows an average deviation of less than 2% above 1 GHz with one given transmission line measurement and does not have the computational challenges seen in a 3D full-wave solver.
Tabakkonsum und Tabakentwöhnung in der Schwangerschaft
Authors: Rasenack Regina , Jähne Andreas
Published: September 2010

Allgemeine Problemstellung: Rauchen ist der wichtigste reversible Risikofaktor für nicht erfolgreich verlaufende Schwangerschaften. In Deutschland rauchen 1/3 aller Frauen bei Schwangerschaftsbeginn und noch etwa 1/5 zum Zeitpunkt der Geburt. Konsequenzen des Tabakkonsums: Zu den negativen Auswirkungen des Tabakkonsums gehört eine erhöhte Wahrscheinlichkeit für unerfüllten Kinderwunsch, Extrauteringravidität, Fehlgeburt, Plazenta praevia und vorzeitige Lösung, mehr Früh- und Mangelgeburten sowie eine erhöhte perinatale Mortalität und Morbidität. Kinder von Raucherinnen haben ein höheres Risiko für plötzlichen Kindstod (SIDS), Atemwegserkrankungen, Verhaltensstörungen (insbesondere ADHS), Übergewicht und eigene Tabakabhängigkeit. Schlussfolgerungen: Jede rauchende Schwangere sollte eine Beratung und psychologische Unterstützung zum Rauchstopp erhalten. Zusätzlich Nikotinsubstitution kann bei Unfähigkeit zur Abstinenz den Effekt der Intervention verstärken.
Frequency and morphology of tropical tropopause layer cirrus from CALIPSO observations: Are isolated cirrus different from those connected to deep convection?
Authors: Riihimaki L. D. , McFarlane S. A.
Published: September 2010

Tropical tropopause layer cirrus (TTLC) profiles identified from CALIPSO lidar measurements are grouped into cloud objects and classified according to whether or not they are directly connected to deep convection. TTLC objects directly connected to deep convection are optically and physically thicker than isolated objects, consistent with what would be expected if convective objects were formed from convective detrainment and isolated objects formed in situ. The frequency of occurrence of these different classifications of TTLC varies depending on height and region. Thirty‐six percent of TTLC profiles contain convective TTLC when TTLC is defined with cloud base height greater than 14 km (±20° Latitude). This estimate of convective TTLC is thought to be a lower limit on the percentage of TTLC formed by convective detrainment. Aged anvil that has persisted longer than the thick regions of the convective cloud would not be classified as convective in our classification. Regions with higher occurrence of deep convection also have higher occurrence of TTLC, and a greater percentage of those TTLC are classified as convective. Definitions of TTLC using higher cloud base height thresholds contain a smaller percentage of TTLC that are classified as convective. Cloud top heights of both isolated and convective TTLC are distributed similarly with respect to the height of the cold point tropopause. Cloud optical depths were found to be higher in TTLC over thick clouds than in TTLC over clear sky during the day but not in night measurements. It is not clear whether this has a physical cause or is due to daytime measurement uncertainties. Both cloud base and top heights are higher over deep convection than over clear sky.
Gravity wave–tidal interactions in the mesosphere and lower thermosphere over Rothera, Antarctica (68°S, 68°W)
Authors: Beldon C. L. , Mitchell N. J.
Published: September 2010

A simple technique for measuring gravity wave activity has been used to investigate gravity wave–tidal interactions in the polar mesosphere and lower thermosphere (MLT). The technique uses the radial velocities of individual meteors recorded by meteor radar to derive a statistical measure (variance) of the activity of the high‐frequency gravity wave field. This technique can measure gravity waves with horizontal wavelengths of up to about 400 km and periods up to approximately 3 hours. Interactions between the observed gravity wave field and the background wind are investigated using data collected between February 2005 and December 2008 by a meteor radar based at Rothera, Antarctica (68°S, 68°W). The results reveal the presence of significant modulations of the observed gravity wave field at tidal periods of 12 and 24 hours. Correlations between the hourly zonal winds and the gravity wave field measured by the meteor radar reveal an in‐phase relationship between the hourly zonal winds and gravity wave variance in winter and an anti‐phase relationship in summer. This is consistent with the theory of filtering by tidal winds acting on a zonally‐asymmetric gravity wave field in which westward waves dominate in winter and eastward waves dominate in summer. The limitations of the technique and the effect this has on the interpretation of these results are also considered. The effects of the diurnal cycles in meteor count rates, the uncertainty in recorded radial velocities and the uncertainty in the measured heights of meteors are considered.
El Niño and La Niña amplitude asymmetry caused by atmospheric feedbacks
Authors: Frauen Claudia , Dommenget Dietmar
Published: September 2010

Interannual variability of tropical Pacific sea surface temperatures (SST) has an asymmetry with stronger positive events, El Niño, and weaker negative events, La Niña, which is generally attributed to processes in the ocean. Here we present evidence from a new hybrid coupled model that the asymmetry and seasonality of El Niño can be caused by nonlinear and seasonally varying atmospheric feedbacks. The model consists of the ECHAM5 global atmospheric general circulation model (GCM) coupled to the 2‐dimensional El Niño linear recharge oscillator ocean model in the tropical Pacific and a mixed layer ocean elsewhere. Despite the models simplistic and, by construction, linear representation of the ocean dynamics, it is able to simulate the main statistical features of El Niño including period, seasonality, skewness, and kurtosis. Analyses of the model show that a nonlinear relationship between zonal wind stress and SST is causing the El Niño‐La Niña asymmetry.
Blocking TLR2 in vivo Protects against Accumulation of Inflammatory Cells and Neuronal Injury in Experimental Stroke
Authors: Ziegler Gina , Freyer Dorette , Harhausen Denise , Khojasteh Uldus , Nietfeld Wilfried , Trendelenburg George
Published: September 2010

Reduced infarct volume in TLR2-knockout mice compared with C57Bl/6 wild-type mice has recently been shown in experimental stroke and confirmed in this study. We now also show a significant decrease of CD11b-positive cell counts and decreased neuronal death in the ischemic hemispheres of TLR2-deficient mice compared with C57Bl/6wt mice 2 days after transient focal cerebral ischemia. To examine the potential benefit of intravascular TLR2 inhibition, C57Bl/6wt mice were treated intraarterially with TLR2-blocking anti-TLR2 antibody (clone T2.5) after 45 minutes of cerebral ischemia and compared with control antibody (isotype) treated wild-type mice. Whereas T2.5-treated mice had no reduction in infarct volumes at 48 hours after reperfusion, they did have decreased numbers of CD11b-positive inflammatory cells and decreased neuronal death compared with isotype-treated control mice. Comparison of the isotype antibody treatment to control (saline) treatment showed no effects on infarct volumes or neuronal survival. However, mice treated with the control isotype antibody had increased numbers of CD11b-positive inflammatory cells compared with saline-treated animals. Thus, antibody treatment itself (i.e., control isotype antibody, but potentially of any antibody) may have adverse effects and limit therapeutic benefit of anti-TLR2-antibody therapy. We conclude that TLR2 mediates leukocyte and microglial infiltration and neuronal death, which can be attenuated by TLR2 inhibition. The TLR2 inhibition in vivo improves neuronal survival and may represent a future stroke therapy.
Elucidating the contribution of the elemental composition of fetal calf serum to antigenic expression of primary human umbilical-vein endothelial cells in vitro
Authors: Bryan Nicholas , Andrews Kirstie D. , Loughran Michael J. , Rhodes Nicholas P. , Hunt John A.
Published: September 2010

One of the major obstacles to obtaining human cells of a defined and reproducible standard suitable for use as medical therapies is the necessity for FCS (fetal calf serum) media augmentation in routine cell culture applications. FCS has become the supplement of choice for cell culture research, as it contains an array of proteins, growth factors and essential ions necessary for cellular viability and proliferation in vitro. It is, however, a potential route for the introduction of zoonotic pathogens and makes defining the cell culture milieu impossible in terms of reproducibility, as the precise composition of each batch of serum not only changes but is in fact extremely variable. The present study determined the magnitude of donor variations in terms of elemental composition of FCS and the effect these variations had on the expression of a group of proteins associated with the antigenicity of primary human umbilical-vein endothelial cells, using a combination of ICPMS (inductively coupled plasma MS) and flow cytometry. Statistically significant differences were demonstrated for a set of trace elements in FCS, with correlations made to variations in antigenic expression during culture. The findings question in detail the suitability of FCS for the in vitro supplementation of cultures of primary human cells due to the lack of reproducibility and modulations in protein expression when cultured in conjunction with sera from xenogeneic donors.
Percolation of ferromagnetism in ZnO codoped with Fe and Mg
Authors: Laiho R. , Ojala I. , Vlasenko L.
Published: September 2010

Magnetic properties of ZnxFe1−xO nanopowder and Zn1−x−yFexMgyO ceramic samples are investigated at temperatures between T=(5–400) K, showing in the latter compound ferromagnetic (FM) interactions up to T∼330 K. When the Fe and Mg concentrations are increased, the amplitude of the Fe3+ electron spin resonance lines decrease while the FM resonance lines grow. The Curie–Weiss type temperature dependence of the magnetization M(T)∝1/T observed for Zn0.89Fe0.01Mg0.10O suggests that in this sample the magnetic interactions are caused by single polarons and small clusters. Strong growth of M(T) and room temperature ferromagnetism are observed in Zn0.70Fe0.04Mg0.26O where the magnetic susceptibility follows the scaling law [χ−1(T)−χ−1(Tc)]∼(T/TC−1)γ with exponents γ1=1.43 typical of three-dimensional (3D) Heisenberg spin systems above the critical temperature Tcr=330 K, and γ2=1.75 characteristic of 3D cluster percolation below Tcr. The estimated critical cluster radius is 40 nm. The M(B) curves are anhysteretic and no time dependence of the thermoremanent magnetization is observed.
Effect of the Prandtl number on a stratified turbulent wake
Authors: de Stadler Matthew B. , Sarkar Sutanu , Brucker Kyle A.
Published: September 2010

Direct numerical simulation is employed to study the effect of the Prandtl number, Pr=ν/α with ν the molecular viscosity and α the molecular diffusivity, on a turbulent wake in a stratified fluid. Simulations were conducted at a Reynolds number of 10 000, Re=UD/ν with U the velocity of the body and D the diameter of the body, for a range of Prandtl numbers: 0.2, 1, and 7. The simulations were run from x/D=6 to x/D=1200, a range that encompasses the near, intermediate, and far wake. Mean quantities such as wake dimensions and defect velocity were found to be weakly affected by Prandtl number, the same result was observed for vorticity as well. The Prandtl number has a strong effect on the density perturbation field and this results in a number of differences in quantities such as the total energy of the wake, wave flux, scalar and turbulent dissipation, mixing efficiency, spectral distribution of energy in the density and velocity fields, and the transfer of energy between kinetic and potential modes. The approximation Pr=1 for the ocean is often used in practice. As the qualitative behavior of the large-scale features was the same for the three cases, we conclude that Pr=1 is a reasonable approximation for the Pr=7 case in stratified wake simulations, given the significantly higher computational cost required at large Prandtl number.
Long-range dispersion coefficients for Li, Li+, and Be+ interacting with the rare gases
Authors: Tang Li-Yan , Zhang Jun-Yi , Yan Zong-Chao , Shi Ting-Yun , Mitroy J.
Published: September 2010

The long-range dispersion coefficients for the ground and excited states of Li, Li+, and Be+ interacting with the He, Ne, Ar, Kr, and Xe atoms in their ground states are determined. The variational Hylleraas method is used to determine the necessary lists of multipole matrix elements for He, Li, Li+, and Be+, while pseudo-oscillator strength distributions are used for the heavier rare gases. Some single electron calculations using a semiempirical Hamiltonian are also performed for Li and Be+ and found to give dispersion coefficients in good agreement with the Hylleraas calculations. Polarizabilities are given for some of the Li and Li+ states and the recommended L7i+ polarizability including both finite-mass and relativistic effects was 0.192 486 a.u. The impact of finite-mass effects upon the dispersion coefficients has been given for some selected interatomic interactions.
Probability distribution of the radius of gyration of freely jointed chains
Authors: Lei Jinzhi
Published: September 2010

In this paper, we present a new approach to study the probability distribution of the radius of gyration of freely jointed chains. In this approach, we study the joint distribution PN(Rg2,R⃗G), where Rg is the radius of gyration and R⃗G is the vector from the first bead to the center of the chain. We derive an iteration relation between the probability distributions of chains with lengths N and N+1. When the chain length is large, the iteration relation can be approximated by an evolution equation with integral determining condition. The equation is solved to obtain the probability distribution function, which yields the known result obtained by Fixman [J. Chem. Phys. 36, 306 (1962)] using the integral method. We hope the iteration method in this paper could be used to study the probability distribution of the structure factor of polymer molecules.
Theoretical specific heat from spin wave in comparison with experimental results in Fe-oxide superconductors
Authors: Jun Li , Yu-Feng Zhang , Zhi-Jie Qin , Xiao-Li Niu , Dong-Sheng Li , Ping-Lin Li
Published: September 2010

Based on the magnetic order of Fe-oxide superconductors from experiments we apply the Heisenberg interaction model to analyze systematically the antiferromagnetic configuration with a spin-density-wave by a rigorous mathematical–physical derivation and to suggest analytic expressions for the internal energy and specific heat under long-wave conditions. The theoretical values show good agreement with experiments; the theoretical and experimental results are discussed in terms of the phonon contribution to the specific heat, so that the spin-density-wave theory can properly describe the physical characteristics of Fe-oxide superconductors.
Instability in threshold voltage and subthreshold behavior in Hf–In–Zn–O thin film transistors induced by bias-and light-stress
Authors: Ghaffarzadeh Khashayar , Nathan Arokia , Robertson John , Kim Sangwook , Jeon Sanghun , Kim Changjung , Chung U-In , Lee Je-Hun
Published: September 2010

Electrical bias and light stressing followed by natural recovery of amorphous hafnium-indium-zinc-oxide (HIZO) thin film transistors with a silicon oxide/nitride dielectric stack reveals defect density changes, charge trapping and persistent photoconductivity (PPC). In the absence of light, the polarity of bias stress controls the magnitude and direction of the threshold voltage shift (ΔVT), while under light stress, VT consistently shifts negatively. In all cases, there was no significant change in field-effect mobility. Light stress gives rise to a PPC with wavelength-dependent recovery on time scale of days. We observe that the PPC becomes more pronounced at shorter wavelengths.
Quadrupole photoionization of hydrogen atoms in Debye plasmas
Authors: Lin C. Y. , Ho Y. K.
Published: September 2010

Although a great deal of effort has been devoted to investigating dipole photoionization of plasma-embedded atoms, far less is known about the corresponding quadrupole transitions. In the present work, quadrupole photoionization processes for the ground and excited states of hydrogen atoms in Debye plasma are explored using the method of complex coordinate rotation. The plasma shielding effects on the quadrupole photoionization cross sections are reported for a variety of Debye screening lengths and compared to the dipole results accordingly. Under the perturbation of plasma screening, shape resonances and Cooper-type minima occurring in both dipole and quadrupole photoionization cross sections are presented and discussed. Comparisons are made to other theoretical calculations for the dipole photoionization with good agreement. The present quadrupole results are the first predictions for hydrogen photoionization in Debye plasmas.
Micromechanical properties of nanocrystalline titanium obtained by cryorolling
Authors: Fomenko L. S. , Rusakova A. V. , Lubenets S. V. , Moskalenko V. A.
Published: September 2010

It is shown by microindentation that the defect structure of nanocrystalline titanium obtained by rolling at low temperature is quite uniform. The presence of texture was manifested as a small difference of the average values of the hardness H¯V and the standard deviation in the measurements in the roll plane and in a plane perpendicular to the roll direction. The data on the temperature dependence of the microhardness in the temperature interval 77–300K are used to evaluate the activation volume and the activation energy that characterize the process of plastic deformation of nanocrystalline and coarse-grain titanium under a concentrated force. Evaluations attest to the dislocation nature of local deformation. The relation between the microhardness and the conditional yield stress HV≈3σ0.2 holds well for nanocrystalline titanium. The hardening of titanium with grain-size reduction is accompanied by appreciable decrease of its plastic compliance.
Josephson nanoconstrictions made by AFM plowing of YBa2Cu3O7−x films
Authors: Elkaseh A. A. O. , Perold W. J. , Srinivasu V. V.
Published: September 2010

Using atomic force microscope (AFM) as a lithography tool, we ploughed (a) constant thickness nanoconstriction (∼492 nm) and (b) variable thickness bridges (∼25 to 50 nm) on YBa2Cu3O7−x thin films. We measured I-V characteristics and observed Shapiro steps, giving positive evidence of Josephson effect in these nanobridges. Further the linear temperature dependence of the critical current (Ic) and the well defined Fraunhofer-type pattern of Ic versus the applied magnetic field, rules out any flux flow behavior and firmly establishes Josephson effect in the constant thickness nanoconstriction type junction. The temperature dependence of Ic is again linear in the variable thickness bridge. However the magnetic field dependence of Ic did not show Fraunhofer-type pattern, possibly due to averaging effects. We believe that the observed low field dependence of Ic in these nanobridges allows one to tune the Josephson energy by small applied fields, making these nanojunctions useful for quantum applications like qubits.
Local two-way magnetoelectric couplings in multiferroic composites via scanning probe microscopy
Authors: Xie S. H. , Liu Y. M. , Liu X. Y. , Zhou Q. F. , Shung K. K. , Zhou Y. C. , Li J. Y.
Published: September 2010

Local two-way magnetoelectric (ME) couplings of a multiferroic composite have been characterized at nanoscale using novel scanning probe microscopy techniques we developed. A bilayer multiferroic composite consisting of lead zirconate titanate (PZT) and TbDyFe (TDF) has been fabricated, and the evolution of ferroelectric domains in PZT induced by an external magnetic field is observed by piezoresponse force microscopy, while the evolution of magnetic domains in TDF induced by an external electric field is observed by magnetic force microscopy, confirming the two-way ME couplings in the multiferroic composite. The technique will be useful in characterizing nanoscale ME couplings in a wide range of multiferroic composites.
Communication: Prediction of the rate constant of bimolecular hydrogen exchange in the water dimer using an ab initio potential energy surface
Authors: Wang Yimin , Bowman Joel M. , Huang Xinchuan
Published: September 2010

We report the properties of two novel transition states of the bimolecular hydrogen exchange reaction in the water dimer, based on an ab initio water dimer potential [A. Shank et al., J. Chem. Phys. 130, 144314 (2009)]. The realism of the two transition states is assessed by comparing structures, energies, and harmonic frequencies obtained from the potential energy surface and new high-level ab initio calculations. The rate constant for the exchange is obtained using conventional transition state theory with a tunneling correction. We employ a one-dimensional approach for the tunneling calculations using a relaxed potential from the full-dimensional potential in the imaginary-frequency normal mode of the saddle point, Qim. The accuracy of this one-dimensional approach has been shown for the ground-state tunneling splittings for H and D-transfer in malonaldehyde and for the D+H2 reaction [Y. Wang and J. M. Bowman, J. Chem. Phys. 129, 121103 (2008)]. This approach is applied to calculate the rate constant for the H2O+H2O exchange and also for H2O+D2O→2HOD. The local zero-point energy is also obtained using diffusion Monte Carlo calculations in the space of real-frequency-saddle-point normal modes, as a function of Qim.
Transient electroluminescence dynamics in small molecular organic light-emitting diodes
Authors: Gan Zhengqing , Liu Rui , Shinar Ruth , Shinar Joseph
Published: September 2010

Intriguing electroluminescence (EL) spikes, following a voltage pulse applied to small molecular OLEDs, are discussed, elucidating carrier and exciton quenching dynamics and their relation to device structure. At low temperatures, all devices exhibit spikes at ∼70–300 ns and μs-long tails. At 295 K only those with a hole injection barrier, carrier-trapping guest-host emitting layer, and no strong hole-blocking layer exhibit the spikes. They narrow and appear earlier under post-pulse reverse bias. The spikes and tails are in agreement with a revised model of recombination of correlated charge pairs (CCPs) and initially unpaired charges. Decreased post-pulse field-induced dissociative quenching of singlet excitons and CCPs, and possibly increased post-pulse current of holes that “turn back” toward the recombination zone after having drifted beyond it are suspected to cause the spikes’ amplitude, which exceeds the dc EL.
Radiative lifetime of the a Σ3+ state of HeH+ from ab initio calculations
Authors: Loreau J. , Liévin J. , Vaeck N.
Published: September 2010

The first metastable triplet state of HeH+ was found to be present in ion beam experiments, with its lifetime estimated to be between hundreds of milliseconds and thousand of seconds. In this work, we use ab initio methods to evaluate the radiative lifetimes of the six vibrational levels of the a Σ3+ of HeH+. The transition a Σ3+→X Σ1+ is spin-forbidden, but acquires intensity through spin-orbit interaction with the singlet and triplet Π states. Large scale CASSCF/MRCI calculations using an adapted basis set were performed to determine the potential energy curves of the relevant states of HeH+ as well as the matrix elements of the dipole and spin-orbit operators. The wave functions and energies of the vibrational levels of the a Σ3+ and X Σ1+ states are obtained using a B-spline method and compared to previous works. We find that the radiative lifetime of the vibrational levels increases strongly with v, the lifetime of the v=0 state being 150 s. We also analyze the contributions from discrete and continuum parts of the spectrum. With such a long lifetime, the a Σ3+ state could have astrophysical implications.
Communication: Padé spectrum decomposition of Fermi function and Bose function
Authors: Hu Jie , Xu Rui-Xue , Yan YiJing
Published: September 2010

Padé approximant is exploited for an efficient sum-over-poles decomposition of Fermi and Bose functions. The resulting poles are all pure imaginary and can therefore be used to define Padé frequencies, in analogy with the celebrated Matsubara frequencies. The proposed Padé spectrum decomposition is shown to be equivalent to a truncated continued fraction. It converges significantly faster than other schemes such as the Matsubara expansion at all temperatures. By introducing the characteristic validity length as the measure of approximant, we analyze the convergence properties of different schemes thoroughly. Our results qualify the present scheme the best among all sum-over-poles approaches. Thus, it is of great value in efficient numerical evaluations of integrals involving Fermi/Bose function in various condensed-phase matter problems.
Effects of (NH4)2S and NH4OH surface treatments prior to SiO2 capping and thermal annealing on 1.3 μm GaInAsN/GaAs quantum well structures
Authors: Polojärvi V. , Salmi J. , Schramm A. , Tukiainen A. , Guina M. , Pakarinen J. , Arola E. , Lång J. , Väyrynen I. J. , Laukkanen P.
Published: September 2010

We report the influence of (NH4)2S and NH4OH surface treatments prior to SiO2 capping and subsequent rapid thermal annealing, on optical properties of GaInAsN/GaAs quantum-well (QW) structures. We observed an increase in QW photoluminescence (PL) emission for the (NH4)2S treated samples as compared to the untreated sample. After annealing, also the NH4OH treated sample showed significant improvement in PL. The treatments were also found to decrease the In out-diffusion and reduce the blueshift upon annealing. The PL results are discussed with x-ray diffraction and x-ray photoemission data from SiO2/GaAs, in particular, with changes found in Ga 3d spectra.
Photoconductance of a submicron oxidized line in surface conductive single crystalline diamond
Authors: Stallhofer M. , Seifert M. , Hauf M. V. , Abstreiter G. , Stutzmann M. , Garrido J. A. , Holleitner A. W.
Published: September 2010

We report on sub-bandgap optoelectronic phenomena of hydrogen-terminated diamond patterned with a submicron oxidized line. The line acts as an energy barrier for the two-dimensional hole gas located below the hydrogenated diamond surface. A photoconductive gain of the hole conductivity across the barrier is measured for sub-bandgap illumination. The findings are consistent with photogenerated electrons being trapped in defect levels within the barrier. We discuss the spatial and energetic characteristics of the optoelectronic phenomena, as well as possible photocurrent effects.
New closed Newton–Cotes type formulae as multilayer symplectic integrators
Authors: Simos T. E.
Published: September 2010

In this paper, we introduce new integrators of Newton–Cotes type and investigate the connection between these new methods, differential methods, and symplectic integrators. From the literature, we can see that several one step symplectic integrators have been obtained based on symplectic geometry. However, the investigation of multistep symplectic integrators is very poor. In this paper, we introduce a new numerical method of closed Newton–Cotes type and we write it as a symplectic multilayer structure. We apply the symplectic schemes in order to solve Hamilton’s equations of motion which are linear in position and momentum. We observe that the Hamiltonian energy of the system remains almost constant as integration proceeds.
Properties of hybrid organic-inorganic systems: Au nanoparticles embedded into an organic CuPc matrix
Authors: Aristov V. Yu. , Molodtsova O. V. , Laubschat C. , Zhilin V. M. , Aristova I. M. , Kveder V. V. , Knupfer M.
Published: September 2010

The evolution of the morphology and the electronic structure of the hybrid organic-inorganic system composed of gold nanoparticles (NPs) distributed in an organic matrix—copper phthalocyanine (CuPc)—as a function of nominal gold content was studied by transmission electron microscopy and by surface and bulk sensitive spectroscopic methods. The gold atoms deposited onto the CuPc surface diffuse into the organic matrix and self-assemble to NPs. There is no formation of a continuous metallic Au film on top of the CuPc film up to large nominal coverage of about 130 Å considered in the present study. The gold is assembled in well defined NPs with metallic properties.
Thermoelectric properties of lattice-matched AlInN alloy grown by metal organic chemical vapor deposition
Authors: Tong Hua , Zhang Jing , Liu Guangyu , Herbsommer Juan A. , Huang G. S. , Tansu Nelson
Published: September 2010

Thermoelectric properties of lattice-matched AlInN grown by metal organic chemical vapor deposition were measured and analyzed. The n-type Al0.83In0.17N alloy exhibited thermal conductivity of 4.87 W/(m K) measured by 3ω differential method. The Seebeck coefficient of n-Al0.83In0.17N was measured as −6.012×10−4 V/K by thermal gradient method. The sheet resistivity of n-Al0.83In0.17N was measured by using Van der Pauw method, and the electrical conductivity was measured as 2.38×104/(Ω m). The thermoelectric figure of merit (Z∗T) of n-type Al0.83In0.17N was measured as 0.532 at room temperature (T=300 K). The finding indicates lattice-matched AlInN alloy on GaN as excellent material candidate for thermoelectric application.
Superconducting plasmonics and extraordinary transmission
Authors: Tsiatmas A. , Buckingham A. R. , Fedotov V. A. , Wang S. , Chen Y. , de Groot P. A. J. , Zheludev N. I.
Published: September 2010

Negative dielectric constant and dominant kinetic resistance make superconductors intriguing plasmonic media. Here we report on the first study of one of the most important and disputed manifestations of plasmonics, the effect of extraordinary transmission through an array of subwavelength holes, using a perforated film of high-temperature superconductor. We show that in the millimetric wave part of the spectrum exceptionally strong extraordinary transmission exists in the ideal conductor state, improves in the plasmonic regime of a superconductor, and diminishes in a highly lossy metal.
A new koala (Marsupialia:Phascolarctidae) from the late Oligocene Etadunna Formation, Lake Eyre Basin, South Australia
Authors: Pledge Neville S.
Published: September 2010

An isolated upper molar represents Litokoala thurmerae sp. nov., the eighth species of phascolarctid marsupial (koalas) from the South Australian mid-Tertiary sequence, and the fourth from the late Oligocene Etadunna Formation at Lake Palankarinna. It is the smallest and oldest species, differing from L. kutjamarpensis (Stirton et al. 1967), L. kanunkaensis (Springer 1987) and L. dicktedfordi, sp. nov. (the Riversleigh specimens referred to L. kanunkaensis and L. kutjamarpensis (Black and Archer 1997; Louys et al. 2007) but described here as a new species) in size, and the almost total lack of crenulations on the surfaces of the cusps. This brings to at least five the number of probably arboreal mammal species in the Ngama Local Fauna (Pledge 1984) of Mammalon Hill, Lake Palankarinna – the others being Ektopodon stirtoni (Pledge 1986), Pildra magnus (Pledge 1987a), P. sp. cf. kutjamarpensis (ibid.), and Burramys wakefieldi (Pledge 1987b) – and further supports the riparian forest environment interpretation proposed for this part of the Etadunna sequence (Pledge 1984; Martin 2006).
Two new species of Antechinus Macleay (Dasyuridae:Marsupialia) from mid-Pleistocene cave deposits in eastern central Queensland
Authors: Cramb Jonathan , Hocknull Scott
Published: September 2010

The dasyurid genus Antechinus occurs in numerous Cainozoic fossil sites but until now only one extinct species has been described, Antechinus puteus Van Dyck. Antechinus yammal sp. nov. and A. yuna sp. nov. are described here on the basis of dental remains recovered from middle Pleistocene (between >500 and 205–170 thousand years ago) cave deposits at Mount Etna, eastern central Queensland. Most of these sites are interpreted as closed rainforest palaeoenvironments, and this is the likely habitat of both species. Both taxa are morphologically variable. A. yammal is characterised by complete anterior cingula and well developed posterior cingula on the upper molars; a relatively unreduced, robust P3; and small entoconids. A. yuna is a relatively large species, typified by poorly developed or absent posterior cingula on M1–3, lack of a metacone on M4, and large entoconids on M1–3. Dental morphology suggests that A. yuna was a near relative of the extant A. leo. The dentition of A. yammal shows some similarities to that of A. flavipes, but its exact phylogenetic position is unclear. A. yammal became extinct coincident with the loss of its rainforest habitat some time between 280 and 205–170 thousand years ago. A. yuna survived somewhat longer, but by the late Pleistocene had been replaced by A. flavipes.
Seasonal anoestrus in western grey kangaroos (Macropus fuliginosus ocydromus) in south-western Australia
Authors: Mayberry Chris , Maloney Shane K. , Mawson Peter , Bencini Roberta
Published: September 2010

Public opposition to culling has generated interest in wildlife management through fertility control. Temporary, non-invasive methods of fertility control, such as by xenobiotics, can be best employed with an understanding of the target species’ breeding cycle. We used head length to calculate the conception date of 136 pouch-young of western grey kangaroos (Macropus fuliginosus ocydromus) from four sites around Perth, Western Australia, between May 2006 and October 2008: Thomsons Lake Nature Reserve (n = 80), Harry Waring Marsupial Reserve (n = 11), Melville Glades Golf Club (n = 29), and Marangaroo Golf Course (n = 16). In total, 78% of all pouch-young were conceived in the months of December–February, 11% in November, 6% in March, and less than 2% in each of October, April and May. We examined the ovaries of 134 females culled from Thomsons Lake Nature Reserve during the months of May–July 2006. Only seven ovaries had a follicle of at least 5 mm and none had an active corpus luteum. These data indicate that the breeding activity M. f. ocydromus is restricted almost exclusively to the months of November–February. A practical application of this finding is that temporary fertility controls applied early in October will provide a full year of birth control if they remain active for seven months.
Detection of medium-sized ground-dwelling mammals using infrared digital cameras: an alternative way forward?
Authors: Claridge Andrew W. , Paull David J. , Barry Simon C.
Published: September 2010

Infrared digital cameras were used to examine temporal detection rates of medium-sized ground-dwelling mammals in a coastal woodland landscape. From three successive deployments at fixed stations, a range of mammals was detected, including three target species: the long-nosed bandicoot, the long-nosed potoroo and the southern brown bandicoot. Reporting rates of target species were largely consistent and in some cases high. The swamp wallaby was the most commonly detected species, ranging from 47–67% of cameras on any given deployment. Long-nosed bandicoots were detected at 37–53% of cameras, long-nosed potoroos 13–23% and southern brown bandicoots 10–17%. In total, bandicoots and potoroos were detected at 23 of 30 sites (77%) while forage-diggings of these mammals were universally present. There were differences in the detection rate of bandicoots and potoroos in relation to 24-hourly cycles: all three species were less likely to be detected between dawn and dusk than dusk and dawn. Otherwise, with few exceptions, the rate at which bandicoots and potoroos were detected over time within a deployment did not vary markedly. Infrared digital cameras offer great potential as sampling devices for bandicoots and potoroos because of their greater detection efficiency relative to other techniques.
Bronchogenic carcinoma in a male rock wallaby (Petrogale lateralis lateralis)
Authors: Willers Nicole , Butler Roy , Mayberry Chris , Mawson Peter
Published: September 2010

Rock wallabies (Petrogale spp.) often occur on isolated rocky outcrops in low-rainfall areas. One male wallaby, from a population of black-flanked rock wallabies (P. lateralis lateralis) being surveyed as part of an ecology and fertility study, died following capture. Post mortem examination revealed the animal to be in poor condition with signs of chronic stress and an extensive, metastasising bronchogenic carcinoma.
Exponential Polynomial Fitting for Fibre Spectrum CCD Profiles
Authors: Zhu Zhangqin , Zhu Jia , Qin Hanqin , Wang Chong , Ye Zhongfu
Published: September 2010

A fibre spectrum profile fitting method based on the least-squares method is presented in this article. For each spectrum of one fibre in spatial orientation, two exponential functions are employed to approximate the profile. Experiments are performed with both simulated profiles and observed profiles to demonstrate the effectiveness of the algorithm. Specially, the proposed method has a better performance for profiles that are asymmetric or composed of multi-Gaussian functions.