bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of using prebiotic and probiotic products on intestinal micro-flora of the honeybee (Apis mellifera carpatica)
Authors: Pătruică S. , Mot D.
Published: March 2012

Maintaining bee colonies in a healthy state throughout the year is one of the main concerns of apiculture researchers. The phenomenon of disappearance of bee colonies is determined by several factors, one of which is bee disease. Due to the organizational structure of the bee colony, disease transmission is rapid, especially through infected food or via the nurse worker bees that feed the brood bees of the colony concerned. The practice of stimulating the bee colonies in spring using sugar syrup feeds with added prebiotic products (lactic acid or acetic acid) and probiotics (Lactobacillus acidophilus LA-14 and Bifidobacterium lactis BI-04) by using an Enterobiotic product (Lactobacillus casei), marketed as Enterolactis Plus, for three weeks, resulted in a significant reduction of the total number of bacteria in the digestive tracts of the bees, compared with the control group. By contrast, intestinal colonization with beneficial bacteria contained in probiotics products administered to the bees was observed. This resulted in an improved health status and bio productive index of the bee colonies studied.
EXISTENCE OF INFINITELY MANY SOLUTIONS FOR SUBLINEAR ELLIPTIC PROBLEMS
Authors: ZHONG X. , ZOU W.
Published: March 2012

We study the following nonlinear Dirichlet boundary value problem:

where Ω is a bounded domain in ℝN(N ≥ 2) with a smooth boundary ∂Ω and g ∈ C(Ω × ℝ) is a function satisfying $\displaystyle \underset{|t|\rightarrow 0}{\lim}\frac{g(x, t)}{t}= \infty$ for all x ∈ Ω. Under appropriate assumptions, we prove the existence of infinitely many solutions when g(x, t) is not odd in t.
The syntax of argument structure: Evidence from Italian complex predicates
Authors: FOLLI RAFFAELLA , HARLEY HEIDI
Published: March 2012

This paper provides an analysis of Italian complex predicates formed by combining a feminine nominalization in -ataand one of three light verbs:fare‘make’,dare‘give’ andprendere‘take’. We show that the constraints governing the choice of light verb follow from a syntactic approach to argument structure, and that several interpretive differences between complex and simplex predicates formed from the same verb root can be accounted for in a compositional, bottom–up approach. These differences include variation in creation vs. affected interpretations of Theme objects, implications concerning the size of the event described, the (un)availability of a passive alternant, and the agentivity or lack thereof of the subject argument.
A review of the biology of European cockles (Cerastodermaspp.)
Authors: Malham Shelagh K. , Hutchinson Thomas H. , Longshaw Matt
Published: March 2012

This review examines the biology of the two main cockle speciesCerastoderma eduleandC. glaucumfound in coastal areas around the north-east Atlantic from Norway to Morocco and through the Baltic, Mediterranean and Black Sea. It considers those factors in particular that impact on the overall health and survival of individuals as well as populations. Methods for the discrimination of the species are reviewed as well as the approaches being taken to delineate different populations, which is crucial to appropriately manage individual fisheries. Cockle populations generally undergo sexual maturation during their second summer and sexes are separate. Eggs are pelagic, with larvae being both benthic and pelagic before settling on the sediment and becoming benthic adults. However, data are lacking on basic larval biology and dispersal mechanisms. Data are provided on predator–prey relationships including information on types of food of importance to cockles. Main predators of cockles include brown shrimp, shore crabs, gastropods, polychaetes, fish and a variety of birds and these can be important in structuring cockle populations. Predation of larval cockles by adult cockles through larviphagy can lead to reductions of up to 40% of the population. Cockles are sensitive to a wide range of chemical contaminants but few data are published on impacts on cockles, in particular larval stages. The review concludes with an assessment of future climate change scenarios on cockles and considers some areas of future research required to preserve this ecologically and economically important species.
Using the musical score to perform: A study with Spanish flute students
Authors: Marín Cristina , Pérez Echeverría Ma Puy , Hallam Susan
Published: April 2012

Musical scores constitute a key element in the development of expertise in musicians from western tonal traditions, since they act as a mediator between the performer and the music itself. Our aim was to study the role of musical scores in instrumental performance practice by analysing the process of learning a new piece of music, as well as the frequency of activities related to that score, taking account of situations when studying alone and with a teacher. Sixteen flute students at two different education levels from conservatoires in Madrid participated in an individual semi-structured interview and completed a rating-scale questionnaire. Categorical analysis from interview data revealed differences between levels in relation to the activities they stated that they engaged in when learning new pieces. Results from the questionnaires showed that although students at both levels worked on playing the musical score correctly, higher-level students seemed to pay special attention to artistic issues. The findings are discussed in relation to previous research, as well as their implications for education.
Effects of influenza antivirals on individual and population immunity over many epidemic waves
Authors: PEPIN K. M. , RILEY S. , GRENFELL B. T.
Published: March 2012

Antivirals are an important defence against novel strains of influenza. However, the impact of widespread drug usage on strain circulation across multiple epidemic waves – via their impact on host immunity – is unknown despite antivirals having the likelihood of extensive use during a pandemic. To explore how drug usage by individuals affects population strain dynamics, we embedded a two-strain model of within-host dynamics within an epidemic model. We found that when 40% of hosts took drugs early during the infectious period, transmission was reduced by 30% and average levels of immunity by 2·9-fold (comparable to antibody concentrations), relative to 14% and 1·5-fold reductions when drugs were taken late. The novel strain was more successful relative to the resident strain when drugs were not taken, and an intermediate level of drug coverage minimized incidence in subsequent waves. We discuss how drug regimens, coverage andR0could impact pandemic preparedness.
The Nordic Nutrition Recommendations and prostate cancer risk in the Cancer of the Prostate in Sweden (CAPS) study
Authors: Möller Elisabeth , Galeone Carlotta , Adami Hans-Olov , Adolfsson Jan , Andersson Therese M-L , Bellocco Rino , Grönberg Henrik , Mucci Lorelei A , Bälter Katarina
Published: March 2012

Objective

The Nordic Nutrition Recommendations (NNR) aim at preventing diet-associated diseases such as cancer in the Nordic countries. We evaluated adherence to the NNR in relation to prostate cancer (PC) in Swedish men, including potential interaction with a genetic risk score and with lifestyle factors.

Design

Population-based case–control study (Cancer of the Prostate in Sweden (CAPS), 2001–2002). Using data from a semi-quantitative FFQ, we created an NNR adherence score and estimated relative risks of PC by unconditional logistic regression. Individual score components were modelled separately and potential modifying effects were assessed on the multiplicative scale.

Setting

Four regions in the central and northern parts of Sweden.

Subjects

Incident PC patients (n 1386) and population controls (n 940), frequency-matched on age and region.

Results

No overall association with PC was found, possibly due to the generally high adherence to the NNR score and its narrow distribution in the study population. Among individual NNR score components, high compared with low intakes of polyunsaturated fat were associated with an increased relative risk of localized PC. No formal interaction with genetic or lifestyle factors was observed, although in stratified analysis a positive association between the NNR and PC was suggested among men with a high genetic risk score but not among men with a medium or low genetic risk score.

Conclusions

Our findings do not support an association between NNR adherence and PC. The suggestive interaction with the genetic risk score deserves further investigations in other study populations.
Entwicklung und Validierung einer Kurzskala zur Erfassung von Technikbereitschaft
Authors: Neyer Franz J. , Felber Juliane , Gebhardt Claudia
Published: March 2012

Zusammenfassung. Die Autoren stellen ein Modell der Technikbereitschaft vor, nach dem individuelle Unterschiede in der Bereitschaft zum Umgang mit Technik in drei unterscheidbare Facetten untergliedert werden können: Technikakzeptanz, Technikkompetenz- und Technikkontrollüberzeugungen. Technikbereitschaft soll den erfolgreichen Umgang mit neuen Technologien insbesondere im höheren Lebensalter vorhersagen. Die Messeigenschaften einer neu entwickelten Skala wurden in drei Studien (N = 825) überprüft. Die Ergebnisse zeigen, dass das Modell der Technikbereitschaft empirisch bestätigt werden kann und das Instrument gute psychometrische Eigenschaften besitzt. Die Konstruktvalidität wurde über Zusammenhänge mit theoretisch einschlägigen Referenzkonstrukten (Techniknutzung, Persönlichkeit, Indikatoren erfolgreichen Alterns) sowie konkurrierend gegenüber anderen Maßen der Technikakzeptanz überprüft.
Vertical turbulent iron flux sustains the Green Belt along the shelf break in the southeastern Bering Sea
Authors: Tanaka T. , Yasuda I. , Kuma K. , Nishioka J.
Published: March 2012

To evaluate the impact of vertical turbulent iron flux on the summertime biological productivity in the Bering Sea Green Belt (GB), we conducted the concurrent observations of dissolved iron (D‐Fe) and turbulence in the Bering Sea for the first time. We show that the GB can be sustained by iron supply from iron‐rich, subsurface thick layer distributed along the southeastern shelf break where the GB is located, via strong turbulent vertical mixing. The flux ratio of D‐Fe and nitrate was within the range of the N/Fe uptake ratio by GB phytoplankton, suggesting this flux of nutrients can sustain GB productivity. We also analyzed historical hydrographic data and suggest the thick subsurface layer along the GB is formed by the mixing of relatively warm water with some iron from the Aleutian Passes and iron‐rich outer‐shelf cold water in which the D‐Fe derived from seafloor sediment is suspended due to strong vertical mixing.
Spin torque switching of 20 nm magnetic tunnel junctions with perpendicular anisotropy
Authors: Gajek M. , Nowak J. J. , Sun J. Z. , Trouilloud P. L. , O’Sullivan E. J. , Abraham D. W. , Gaidis M. C. , Hu G. , Brown S. , Zhu Y. , Robertazzi R. P. , Gallagher W. J. , Worledge D. C.
Published: March 2012

Spin-transfer torque magnetic random access memory (STT-MRAM) is one of the most promising emerging non-volatile memory technologies. MRAM has so far been demonstrated with a unique combination of density, speed, and non-volatility in a single chip, however, without the capability to replace any single mainstream memory. In this paper, we demonstrate the basic physics of spin torque switching in 20 nm diameter magnetic tunnel junctions with perpendicular magnetic anisotropy materials. This deep scaling capability clearly indicates the STT MRAM device itself may be suitable for integration at much higher densities than previously proven.
A new high performance field reversed configuration operating regime in the C-2 device
Authors: Tuszewski M. , Smirnov A. , Thompson M. C. , Akhmetov T. , Ivanov A. , Voskoboynikov R. , Barnes D. , Binderbauer M. W. , Brown R. , Bui D. Q. , Clary R. , Conroy K. D. , Deng B. H. , Dettrick S. A. , Douglass J. D. , Garate E. , Glass F. J. , Gota H. , Guo H.Y. , Gupta D. , Gupta S. , Kinley J. S. , Knapp K. , Korepanov S. , Longman A. , Hollins M. , Li X. L. , Luo Y. , Mendoza R. , Mok Y. , Necas A. , Primavera S. , Ruskov E. , Schmitz L. , Schroeder J. H. , Sevier L. , Sibley A. , Song Y. , Sun X. , Trask E. , Van Drie A. D. , Walters J. K. , Wyman M. D. ,   TAE Team
Published: March 2012

Large field reversed configurations (FRCs) are produced in the C-2 device by combining dynamic formation and merging processes. The good confinement of these FRCs must be further improved to achieve sustainment with neutral beam (NB) injection and pellet fuelling. A plasma gun is installed at one end of the C-2 device to attempt electric field control of the FRC edge layer. The gun inward radial electric field counters the usual FRC spin-up and mitigates the n = 2 rotational instability without applying quadrupole magnetic fields. Better plasma centering is also obtained, presumably from line-tying to the gun electrodes. The combined effects of the plasma gun and of neutral beam injection lead to the high performance FRC operating regime, with FRC lifetimes up to 3 ms and with FRC confinement times improved by factors 2 to 4.
Theory of ferromagnetic wires resonating in the proximity of a ground plane: Application to artificial impedance surfaces
Authors: Liberal I. , Ederra I. , Gonzalo R.
Published: March 2012

Ferromagnetic wires are proposed to engineer artificial impedance surfaces. The scattering problem of a grid of wires in the proximity of a ground plane is solved, and explicit expressions for the equivalent surface impedance and reflection coefficient are formulated. Due to the wide variety of electromagnetic effects excited by the wires (magneto-impedance effect, magnetic dipolar excitation, and inter-coupling between both effects and higher order effects) ferromagnetic wires provide more design flexibility than state of the art impedance surfaces. The scenario of dominant magnetic dipolar excitation is addressed in detail, demonstrating the possibility of realizing absorbing boundaries as well as capacitive and/or inductive surfaces.
Vlasov-Maxwell equilibria: Examples from higher-curl Beltrami magnetic fields
Authors: Janaki M. S. , Dasgupta Brahmananda
Published: March 2012

Stationary solutions of Vlasov-Maxwell equations are obtained by exploiting the invariants of single particle motion and lead to linear or nonlinear functional relations between current and vector potential. The nonlinear relations support various special types of magnetic configurations including multiple current sheets and magnetic field discontinuities leading to singular current layers. It is demonstrated through the examples that in one dimension, the description of the equilibrium magnetic fields obeys double or higher-curl Beltrami equation. For the linear case, such representation gives the advantage of obtaining exact analytic solutions that are expressed as a superposition of the single-curl Beltrami fields.
Inverse bremsstrahlung heating rate in atomic clusters irradiated by femtosecond laser pulses
Authors: Moll M. , Bornath Th. , Schlanges M. , Krainov V. P.
Published: March 2012

In the interaction of atomic clusters with femtosecond laser pulses, nanoplasmas with high density and high temperature are created. The heating is mainly determined by inverse bremsstrahlung (IB) due to electron-ion collisions. In many approaches for the calculation of the IB heating rate such as the Born approximation, large-angle scattering events are underestimated. However, rescattering events of an electron on the same atomic ion play an important role because they increase the amount of energy exchanged between the electrons and the laser field. In noble gas plasmas, the electron-ion interaction is often considered to take place between point-like particles. For typical noble gas clusters studied in experiments, one is advised to take into account not only the screening by the surrounding plasma medium but also the inner structure of the ions what can be accomplished by the use of appropriate model potentials. In the present paper, the IB heating rate is calculated from the classical simulation of individual electron trajectories. Results are presented for xenon clusters and argon clusters with different degree of ionization. Especially for higher energies, the consideration of the ionic structure increases the heating rate compared with the scattering on point-like particles. The Born approximation, however, overestimates this effect.
Compositional nonuniformities in pulsed laser atom probe tomography analysis of compound semiconductors
Authors: Müller M. , Smith G. D. W. , Gault B. , Grovenor C. R. M
Published: March 2012

The unidirectional laser illumination of atom probe tomography specimens can result in changes of the apex morphology from nearly hemispherical to asymmetrical with different local radii of curvature, implying an anisotropic field distribution across the sample surface. In the analysis of III-V semiconductors, this affects the process of field dissociation of group-V cluster ions and introduces variations in the apparent composition across the field of view. We have studied this phenomenon in GaSb and propose an explanation for these compositional variations in terms of the locally varying extent of field dissociation of group-V cluster ions and ion pile-up effects on the detector. The optimization of experimental conditions and possible modifications to the instrument design are discussed to mitigate the compositional variations.
Observation of the generation and evolution of long-lived runaway electron beams during major disruptions in the HuanLiuqi-2A tokamak
Authors: Zhang Y. P. , Liu Yi , Yuan G. L. , Isobe M. , Chen Z. Y. , Cheng J. , Ji X. Q. , Song X. M. , Yang J. W. , Song X. Y. , Li X. , Deng W. , Li Y. G. , Xu Y. , Sun T. F. , Ding X. T. , Yan L. W. , Yang Q. W. , Duan X. R. , Liu Y. ,   HL-2A Team
Published: March 2012

In an experimental study of the runaway electron generation during major disruptions in the HuanLiuqi-2A (commonly referred to as HL-2A) [L. W. Yan, Nucl. Fusion 51, 094016 (2011)] tokamak, detailed time and space resolved x-ray images of the long-lived runaway electron beam in flight have been observed and these allow a detailed analysis of the generation and evolution of the disruption produced runaway electron beam in a major disruption, where the conversion efficiency of pre-disruption plasma current into runaway current is up to 55% on HL-2A tokamak. Moreover, a delay of about 7 ms between the start of the disruption and the formation of runaway electron beam has been found. With the aid of the Equilibrium FIT (EFIT) code, magnetic configuration reconstruction has made possible a detailed observation of the magnetic flux geometry evolution during major disruptions. The EFIT magnetic configuration reconstructions show that the delay is due to the transient strong deformation of the magnetic configuration in the initial stage of the current quench, which may provide a possibility of suppressing or mitigating the runaway electron beam during this period by massive gas injection or other methods.
Deuterium beam acceleration with 3rd harmonic ion cyclotron resonance heating in Joint European Torus: Sawtooth stabilization and Alfvén eigenmodes
Authors: Gassner T. , Schoepf K. , Sharapov S. E. , Kiptily V. G. , Pinches S. D. , Hellesen C. , Eriksson J. ,   JET-EFDA contributors
Published: March 2012

Experiments on accelerating NBI-produced deuterium (D) beam ions from their injection energy of ∼110 keV up to the MeV energy range with 3rd harmonic ion cyclotron resonance heating were performed on the Joint European Torus [P. H. Rebut and B. E. Keen, Fusion Technol. 11, 13 (1987)]. A renewed set of nuclear diagnostics was used for analysing fast D ions during sawtooth stabilization, monster sawtooth crashes, and during excitation of Alfvén eigenmodes (AEs) residing inside the q = 1 radius. The measurements and modeling of the fast ions with the nonlinear HAGIS code [S. D. Pinches et al., Comput. Phys. Commun. 111, 133 (1998)] show that monster sawtooth crashes are strongly facilitated by the AE-induced re-distribution of the fast D ions from inside the q = 1 radius to the plasma edge.
Speed dependence of collisional relaxation in ground vibrational state of OCS: Rotational behaviour
Authors: Koshelev Maxim A. , Tretyakov Mikhail Yu. , Rohart François , Bouanich Jean-Pierre
Published: April 2012

Accurate experimental data on pressure broadened profiles of 16O12C32S pure rotational lines in a broad range of quantum number J have been analyzed taking into account the speed dependence of collisional relaxation. Refined values of collisional self-broadening coefficients are determined and compared to previously known data. New quantitative information on departures of observed line shapes from the traditional Voigt profile is obtained. It is shown that these departures result mainly from the speed dependence of collisional relaxation. Theoretical calculations of self-broadening parameters are performed in the framework of the semiclassical impact Robert-Bonamy formalism where the mean relative molecular speed as well as the Maxwell-Boltzmann distribution of relative speeds is considered. The necessity of allowance for the speed dependence in line shape models is confirmed and satisfactory results have been obtained by arbitrarily limiting the integration of the differential cross section to a finite value of the impact parameter. It is shown for the first time for the whole rotational spectrum that speed dependent models not only improve accuracy of modeling the observed line profiles but also give physically grounded values of collisional relaxation parameters.
A novel computer simulation method for simulating the multiscale transduction dynamics of signal proteins
Authors: Peter Emanuel , Dick Bernhard , Baeurle Stephan A.
Published: March 2012

Signal proteins are able to adapt their response to a change in the environment, governing in this way a broad variety of important cellular processes in living systems. While conventional molecular-dynamics (MD) techniques can be used to explore the early signaling pathway of these protein systems at atomistic resolution, the high computational costs limit their usefulness for the elucidation of the multiscale transduction dynamics of most signaling processes, occurring on experimental timescales. To cope with the problem, we present in this paper a novel multiscale-modeling method, based on a combination of the kinetic Monte-Carlo- and MD-technique, and demonstrate its suitability for investigating the signaling behavior of the photoswitch light-oxygen-voltage-2-Jα domain from Avena Sativa (AsLOV2-Jα) and an AsLOV2-Jα-regulated photoactivable Rac1-GTPase (PA-Rac1), recently employed to control the motility of cancer cells through light stimulus. More specifically, we show that their signaling pathways begin with a residual re-arrangement and subsequent H-bond formation of amino acids near to the flavin-mononucleotide chromophore, causing a coupling between β-strands and subsequent detachment of a peripheral α-helix from the AsLOV2-domain. In the case of the PA-Rac1 system we find that this latter process induces the release of the AsLOV2-inhibitor from the switchII-activation site of the GTPase, enabling signal activation through effector-protein binding. These applications demonstrate that our approach reliably reproduces the signaling pathways of complex signal proteins, ranging from nanoseconds up to seconds at affordable computational costs.
Effects of hydrogen bond and solvent polarity on the C=O stretching of bis(2-thienyl)ketone in solution
Authors: Wang Huigang , Wang Libo , Shen Shaosong , Zhang Wenfei , Li Mingde , Du Lili , Zheng Xuming , Phillips David Lee
Published: March 2012

The optimized structural parameters, the absorption and the resonance Raman spectra have been investigated for the bis(2-thienyl)ketone in gas phase, in cyclohexane, methanol, and acetonitrile solvents by means of time dependent density functional theory calculations, the solvent electronic polarization effect on the solvation shift is examined and in well accordance with the calculation. The effect of increasing the polarity of the solvent is well represented by the polarizable continuum model, both for the absorption spectra and resonance Raman intensities. The Raman spectra of the C=O stretching mode, which is sensitive to the intermolecular interaction for bis(2-thienyl)ketone dissolved in solvents, were systematically studied. It was found that the hydrogen bond effect plays an important role in reducing the carbonyl stretching wavenumbers. The results of Raman shifts were interpreted through the dilution effect, solvation effects, and hydrogen bond-forming effects. Furthermore, the excitation profiles of several important Raman bands of bis(2-thienyl)ketone molecule in different solvents have been critically analyzed. The solvent effects on structural and symmetry properties of the molecule in S2 electronic state as well as the short-time photo relaxation dynamics have been discussed.
Spin-orbit quenching of Cl(2P1/2) by H2
Authors: Lique François , Alexander Millard H.
Published: March 2012

We report fully-quantum, time-independent, scattering calculations for the spin-orbit quenching of Cl(2P1/2) by H2 molecules at low and moderate temperature. Our calculations take into account chemical reaction channels. Cross sections are calculated for total energies up to 5000 cm−1 which are used to determine, by thermal averaging, state-to-state rate coefficients at temperatures ranging from 50 to 500 K. Spin-orbit relaxation of chlorine is dominated by collisions with H2 in the rotationally excited states j = 2 and j = 3. In the former case the near-resonant energy transfer is the primary relaxation mechanism. The inclusion of the reactive channel could lead differences compared to pure inelastic calculations. Good agreement is obtained with experimental relaxation measurements at room temperature.
Effect of binding on escape from cavity through narrow tunnel
Authors: Berezhkovskii Alexander M. , Dagdug Leonardo
Published: March 2012

When a diffusing particle escapes from a spherical cavity through a narrow, not too long tunnel, the escape kinetics is essentially single-exponential. The presence of reversible binding sites on the cavity wall leads to retention of the particle in the system and converts the single-exponential kinetics into bi-exponential. We develop a theory that describes these effects. The theory shows how the delay time and the average number of binding events depend on the geometric and kinetic parameters of the system. To study the effect of the cavity shape, we also analyze the kinetics when the particle escapes from a cylindrical cavity with reversible binding sites.
Electronic properties of spiro compounds for organic electronics
Authors: Mahns Benjamin , Roth Friedrich , Grobosch Mandy , Lindner Susi , Knupfer Martin , Saragi Tobat P. I. , Reichert Thomas , Salbeck Josef , Hahn Torsten
Published: March 2012

The electronic properties of p-type, n-type, and ambipolar spiro materials have been investigated using a combination of photoemission spectroscopy, electron energy-loss spectroscopy, and density functional based calculations. Our results provide insight into the occupied density of states as well as the electronic excitation spectra. Comparison of experimental and theoretical data allows the identification of the orbitals responsible for charge transport and optical properties.
B2-PPW91: A promising double-hybrid density functional for the electric response properties
Authors: Mohajeri Afshan , Alipour Mojtaba
Published: March 2012

A new double-hybrid density functional, termed B2-PPW91, is presented which includes the Becke88 (B88) exchange in conjunction with Perdew–Wang91 (PW91) gradient-corrected correlation functional. The fitting parameters are obtained by minimization of mean absolute error of the static dipole polarizability of 4d transition metal monohalides against the CCSD(T)/aug-cc-pVTZ/SDD results. The performance of proposed functional has been assessed for estimation of other response properties, such as dipole moment and excitation energy, for the same species. We then proceed to explore the validity of B2-PPW91 method for calculation of the dipole polarizability of some 5d transition metal monofluorides. In all cases, the improvement compared to common density functional methods and even previously reported double-hybrid functionals such as B2-PLYP and mPW2-PLYP has been observed. This indicates that the utility of double-hybrid density functional methods can be further extended to study linear and non-linear optical properties of transition metal containing molecules.
Evaluation of orbital moment in Ni-Zn ferrites: A magnetic Compton scattering study
Authors: Ahuja B. L. , Mund H. S. , Tiwari Shailja , Sahariya Jagrati , Dashora Alpa , Itou M. , Sakurai Y.
Published: March 2012

Temperature dependent magnetic Compton profiles of Ni1−xZnxFe2O4 (x = 0.0, 0.1, 0.2) ferrites have been decomposed into component profiles to determine the site-specific magnetic moments. For a quantitative evaluation of orbital moment, the spin momentum density data have been combined with magnetization data. Interestingly, the orbital magnetic moment decreases from 0.25 ± 0.03 μB/f.u. (for x = 0.0) to 0.09 ± 0.03 μB/f.u. (for x = 0.2) which is in contrast to spin moment. A decrease in ratio of orbital to spin moments in Ni rich ferrites is explained on the basis of spin-orbit coupling and crystal field interaction.
Effect of interfacial interactions and nanoscale confinement on octane melting
Authors: Wang Yan , Keblinski Pawel
Published: March 2012

Molecular dynamics simulations are used to study the thermodynamics and kinetics of the melting process of crystalline octane in contact with solid surfaces. First, we establish a reference by determining the thermodynamic melting point through studying crystalline octane structures with crystal-vapor interfaces. Study of crystalline octane without interfaces allows evaluation of the degree of overheating resulting from the nucleation barrier. When a nanoscopic octane crystal film is confined between two silicon solids, we observe a significant effect on the thermodynamics of the melting process, with effective melting temperature increased by almost 50%. We also performed simulations with constant heat flux to evaluate the role of kinetics and interfacial thermal resistance on the melting process.
Size dependent mechanical properties of single crystalline nickel nanowires
Authors: Peng Cheng , Ganesan Yogeeswaran , Lu Yang , Lou Jun
Published: March 2012

Using a simple micromechanical device, in situ tensile testing of single crystalline nickel (Ni) nanowires (NWs) with different diameters (100 to 300 nm) and crystalline orientations was performed inside a scanning electron microscope. With the aid of a quantitative nanoindenter and corresponding theoretical analysis, the load applied to the sample and the sample displacement were ascertained from nanoindenter load versus displacement curves so as to obtain engineering stress-strain curves. Limited plasticity and brittle-like fracture modes were evident in the Ni NWs investigated, and the breaking strength values were found to be much higher than that of the bulk material. More important, the critical resolved shear stress was found to increase as the NW diameter decreased, showing strong size dependence. The quantitative experimental results from this work could offer important insights into the origin of the size dependent mechanical behaviors of metals at the nano-scale.
Coupling of energy from quantum emitters to the plasmonic mode of V groove waveguides: A numerical study
Authors: Vernon K. C. , Tischler N. , Kurth M. L.
Published: March 2012

This work is a theoretical investigation into the coupling of a single excited quantum emitter to the plasmon mode of a V groove waveguide. The V groove waveguide consists of a triangular channel milled in gold and the emitter is modeled as a dipole emitter, and could represent a quantum dot, nitrogen vacancy in diamond, or similar. In this work the dependence of coupling efficiency of emitter to plasmon mode is determined for various geometrical parameters of the emitter-waveguide system. Using the finite element method, the effect on coupling efficiency of the emitter position and orientation, groove angle, groove depth, and tip radius, is studied in detail. We demonstrate that all parameters, with the exception of groove depth, have a significant impact on the attainable coupling efficiency. Understanding the effect of various geometrical parameters on the coupling between emitters and the plasmonic mode of the waveguide is essential for the design and optimization of quantum dot–V groove devices.
Magnetic properties and magnetocaloric effect of La0.8Ca0.2MnO3 nanoparticles tuned by particle size
Authors: Xi Shaobo , Lu Wenjian , Sun Yuping
Published: April 2012

La0.8Ca0.2MnO3 particles with the sizes from 17 to 43 nm have been prepared using the sol-gel method and the magnetic properties are systematically studied. The existence of the blocking of the superparamagnetism (SPM), freezing of super-spin-glass, and surface-spin-glass is evidenced. It is found that a core-shell structure can be responsible for the magnetism behavior of the nanoparticles. The phase transition from paramagnetism (PM) to ferromagnetism (FM) is modified from first order to second order as the particle size reduced. The magnetocaloric effect (MCE) thus is modified by the changed magnetism. The observed temperature interval of the magnetic entropy change broadens as the particle size reduced. The magnetic entropy change of superparamagnetic particles has been calculated based on the core-shell model. The relative cooling power (RCP) can be tuned dramatically by particle size due to the change of spontaneous magnetization of the core and the changed ratio of the shell and surface, which shows different behavior in magnetization.
High-temperature ferroelectric behaviors of poly(vinylidene fluoride-trifluoroethylene) copolymer ultrathin films with electroactive interlayers
Authors: Hou Ying , Zhang Xiuli , Zhang Yuan , Xu Guoqiang , Xu Haisheng
Published: April 2012

The high-temperature ferroelectric behaviors for poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer ultrathin films with electroactive interlayers have been studied. The different electroactive polymers, commercial poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonic) acid (PEDOT-PSSH), in situ synthesized PEDOT-PSSH with high PEDOT ratio and poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonic) ammonia (PEDOT-PSSNH4), are used as the interlayer between P(VDF-TrFE) and metal electrodes. It is found that the ferroelectric properties at high temperature are strongly dependent on the interlayer and the faster degradation occurs on the sample with the interlayer which has enough protons as compensating charges. Further analysis on the polarization response behaviors and capacitance shows that the high-temperature ferroelectric properties are more closely associated with the compensating charges in interlayer than the ferroelectric film itself, illustrating the importance of the appropriate interlayer materials.
Communication: Time-resolved fluorescence of highly single crystalline molecular wires of azobenzene
Authors: Jee Ah-Young , Lee Yumin , Lee Minyung , Kim Myung Hwa
Published: April 2012

We report the enhanced fluorescence with the remarkably long lifetime (1.17 ns) in the first excited state (S1) of highly crystalline molecular wires of azobenzene at the excitation wavelength of 467 nm for the first time. This observation suggests that trans-cis photoisomerization through the rotation or inversion mechanism may not be a favorable pathway after excitation to the S1 state in highly single crystalline molecular wires of azobenzene due to the hindered motion within densely packed crystal structure. We also measured the fluorescence lifetime image of a single crystalline molecular wire of azobenzene, indicating that the lifetime was remarkably uniform and that there was only a very minor variation within the crystal.
Tree age-related effects on sun acclimated leaves in a chronosequence of beech (Fagus sylvatica) stands
Authors: Louis Juliette , Genet Hélène , Meyer Sylvie , Soudani Kamel , Montpied Pierre , Legout Arnaud , Dreyer Erwin , Cerovic Zoran G. , Dufrêne Eric
Published: March 2012

The assessment of the effect of tree age on leaves is usually limited by the difficulty of sampling sun leaves from tall ageing trees. In this study, we investigated tree age-related effects on sun leaves in a chronosequence of beech (Fagus sylvatica L.) stands. The effects of stand age on leaf mass to area ratio (LMA), chlorophyll (Chl), epidermal polyphenols (EPhen), nitrogen and carbon contents in sun leaves were investigated in 17 even-aged stands distributed into six age classes (14–175 years old). Chl and EPhen were assessed in vivo with SPAD and Dualex portable leaf-clips respectively. Leaves were sampled by shooting and sun leaves were identified based on criteria obtained from a vertical profile of the ratio abaxial vs adaxial EPhen across the canopy. Sun leaves were characterised by a high and similar adaxial and abaxial EPhen contents, high LMA value and low mass-based Chl content. These sun leaf characteristics, together with leaf nitrogen and carbon contents, were not significantly affected by stand age. Along the chronosequence, beech trees invested a stable fraction of leaf mass into nitrogen, carbon, Chl and EPhen with decreasing leaf size, i.e. dry mass and area.
The postpartum endometrial inflammatory response: a normal physiological event with potential implications for bovine fertility
Authors: Chapwanya Aspinas , Meade Kieran G. , Foley Cathriona , Narciandi Fernando , Evans Alexander C. O. , Doherty Michael L. , Callanan John J. , O'Farrelly Cliona
Published: March 2012

After calving, the bovine endometrium undergoes marked morphological and functional changes that are necessary for subsequent re-breeding. Regulation and integration of these key events are largely uncharacterised. Here, endometrial swabs and biopsies were taken at 15, 30 and 60 days postpartum (DPP) from 13 healthy primiparous cows, 10 of which subsequently conceived, with a view to characterising innate and inflammatory gene expression profiles. Endometrial biopsies exhibited severe inflammation (>75 leukocytes per high-power field) at 15 DPP, which had begun to resolve by 30 DPP and had completely resolved by 60 DPP. The severe inflammation at 15 DPP coincided with uterine infection in all cows and a significant increase (P < 0.05) in the expression of all of 16 genes investigated, including CD45, IL8, IL6, IL1, TNF, TAP, SAA3 and HP at 15 DPP, relative to 60 DPP. All of these parameters had begun to return to normal physiological levels at 30 DPP. Systemically, serum protein concentrations of IL-8 were elevated at 15 DPP compared with 60 DPP (78 pg mL–1 vs 48 pg mL–1; P = 0.02). These results indicate that endometrial inflammation, leukocyte infiltration and increased expression of pro-inflammatory, antimicrobial and acute-phase protein genes are expected features of the postpartum period, critical to bacterial clearance and uterine involution.
A critical review of degradation assumptions applied to Mongolia's Gobi Desert
Authors: Addison J. , Friedel M. , Brown C. , Davies J. , Waldron S.
Published: April 2012

Several assumptions about the levels and causes of rangeland degradation in Mongolia are widely accepted by a range of stakeholders. These assumptions have become important in terms of guiding strategies and policy directions. This paper provides a critical analysis of five widely-held assumptions about rangeland degradation in Mongolia to the more specific case of the rangelands of the Gobi Desert. These assumptions are: (i) there are too many animals; (ii) the relative increase in goat numbers has led to desertification; (iii) rainfall is declining; (iv) there is declining pasture biomass; and (v) Mongolian rangelands are degraded. Biophysical and social data from the Dundgobi and Omnogobi desert steppe areas suggest not all of these assumptions are supported all of the time, and that the processes upon which these assumptions are based are often more complex or dynamic than is commonly recognised. In designing policy and programs, more attention to these dynamics and complexities is needed.
The ubiquitin E3 ligase parkin regulates the proapoptotic function of Bax
Authors: Johnson Bethann N. , Berger Alison K. , Cortese Giuseppe P. , LaVoie Matthew J.
Published: March 2012

Autosomal recessive loss-of-function mutations within the
PARK2
gene functionally inactivate the E3 ubiquitin ligase parkin, resulting in neurodegeneration of catecholaminergic neurons and a familial form of Parkinson disease. Current evidence suggests both a mitochondrial function for parkin and a neuroprotective role, which may in fact be interrelated. The antiapoptotic effects of parkin have been widely reported, and may involve fundamental changes in the threshold for apoptotic cytochrome
c
release, but the substrate(s) involved in parkin dependent protection had not been identified. Here, we demonstrate the parkin-dependent ubiquitination of endogenous Bax comparing primary cultured neurons from WT and parkin KO mice and using multiple parkin-overexpressing cell culture systems. The direct ubiquitination of purified Bax was also observed in vitro following incubation with recombinant parkin. We found that parkin prevented basal and apoptotic stress-induced translocation of Bax to the mitochondria. Moreover, an engineered ubiquitination-resistant form of Bax retained its apoptotic function, but Bax KO cells complemented with lysine-mutant Bax did not manifest the antiapoptotic effects of parkin that were observed in cells expressing WT Bax. These data suggest that Bax is the primary substrate responsible for the antiapoptotic effects of parkin, and provide mechanistic insight into at least a subset of the mitochondrial effects of parkin.
On the Waring problem for polynomial rings
Authors: Fröberg Ralf , Ottaviani Giorgio , Shapiro Boris
Published: March 2012

In this note we discuss an analog of the classical Waring problem for

. Namely, we show that a general homogeneous polynomial

of degree divisible by
k
≥2 can be represented as a sum of at most
k

n

k
-th powers of homogeneous polynomials in

. Noticeably,
k

n

coincides with the number obtained by naive dimension count.
Linking disturbance regimes, vegetation dynamics, and plant strategies across complex landscapes to mitigate and manage plant invasions.
Authors: Fuhlendorf S. D. , Allred B. W. , Elmore R. D. , Engle D. M.
Published: March 2012

This chapter aims to present an overview of relevant ecological considerations for invasive species in general and to suggest some ecological factors to consider before initiating management efforts. The evolutionary disturbance processes on rangelands, life histories and plant strategies that promote invasiveness, altered disturbance regimes and global change are discussed.
Weather variability, ecological processes, and optimization of soil micro-environment for rangeland restoration.
Authors: Hardegree S. P. , Cho J. , Schneider J. M.
Published: March 2012

This chapter focuses on rangeland restoration. The chapter makes use of an ecologically-based model to structure a discussion of weather and climate impacts on some key processes affecting succession, the micro-environmental underpinnings of some important restoration management tools, and strategies to incorporate weather information into the restoration-planning cycle for rangelands.
Species performance: the relationship between nutrient availability, life history traits, and stress.
Authors: James J. J.
Published: March 2012

The objectives of this chapter are to: (i) examine current paradigms and assumptions about how nutrient availability influences the relative performance of invasive and native plants; (ii) develop the argument that the influence of nutrient availability on species performance is mediated by life history traits and stressors such as drought and herbivory; and (iii) describe how these principles that determine species performance in different nutrient environments can be used to develop more effective invasive plant management strategies. The current paradigms of nutrient availability and invasion, influence of nutrient management on species performance: the role of life history, drought, and herbivory, and designing ecologically based invasive plant management strategies based on principles of species performance in low and high nutrient environments are discussed.
Game bird breeding, brooding and rearing - health and welfare.
Authors: Pennycott T. , Deeming C. , McMillan M.
Published: March 2012

Large numbers of game birds, mainly pheasants (Phasianus colchicus) and red-legged partridges (Alectoris rufa), are released for sporting purposes in the UK. The released birds are derived from eggs produced by captive breeding flocks and incubated artificially. This chapter considers the systems of housing of adult pheasants and partridges during the breeding season, including group size, stocking density and the use of sight barriers as a means of environmental enrichment and refuge provision. The conditions and constraints of artificial incubation are explored. It is concluded that radical changes to the conditions under which pheasants and partridges are bred will require experimentation and research. Further development of the game industry will also require a switch to modern incubation equipment designed for poultry but adapted to hold pheasant and partridge eggs. The chapter then goes on to describe some of the current methods of rearing pheasants and partridges from day-old to release, and relates husbandry practices to the requirements of the new Codes of Practice for the Welfare of Gamebirds Reared for Sporting Purposes. In general most of the recommendations in the welfare codes are being complied with. Areas that require further attention by game bird rearers include improved environmental enrichment in some systems; the best use of artificial lighting; a re-evaluation of the use of bits; improved cleaning and disinfection of crates and vehicles used to transport birds to release pens; greater involvement of local veterinary practices; preparation of flock health plans; and improved biosecurity.