bluuebunny/crossref_metadata_2025 huggingface dataset:
Proposal of a Double Diamond Model of Social Response
Authors: Nail Paul R. , Di Domenico Stefano I. , MacDonald Geoff
Published: March 2013

Models of social response concern the identification and delineation of possible responses to social pressure. Previous efforts toward a unified model have been limited to conceptualizations that define conformity and its alternatives based on discrete categories (e.g., Montgomery, 1992 ; Nail et al., 2000 ). Social response in many settings, however, is more a matter of degree, requiring continuous-response formats. The authors propose a new unified model, the double diamond, which was derived from a synthesis of 11 existing models. To our knowledge, it includes for the first time in a continuous-response model: two types of conformity, three types of anticonformity, independence, compromise, contagion, and numerous other possibilities. The model provides a needed theoretical foundation for a relatively new influence technique: strategic self-anticonformity ( MacDonald et al., 2011 ). The broader integrative power of the model is illustrated by its links with the true self ( Rogers, 1951 ), self-determination theory ( Ryan & Deci, 2008 ), and two therapeutic techniques— paradoxical intention ( Frankl, 1967 ) and motivational interviewing ( Miller & Rollnick, 2002 ).
Controlling Circadian Rhythms by Dark-Pulse Perturbations in Arabidopsis thaliana
Authors: Fukuda Hirokazu , Murase Haruhiko , Tokuda Isao T.
Published: March 2013

Plant circadian systems are composed of a large number of self-sustained cellular circadian oscillators. Although the light-dark signal in the natural environment is known to be the most powerful Zeitgeber for the entrainment of cellular oscillators, its effect is too strong to control the plant rhythm into various forms of synchrony. Here, we show that the application of pulse perturbations, i.e., short-term injections of darkness under constant light, provides a novel technique for controlling the synchronized behavior of plant rhythm in Arabidopsis thaliana. By destroying the synchronized cellular activities, circadian singularity was experimentally induced. The present technique is based upon the theory of phase oscillators, which does not require prior knowledge of the detailed dynamics of the plant system but only knowledge of its phase and amplitude responses to the pulse perturbation. Our approach can be applied to diverse problems of controlling biological rhythms in living systems.
Tamm states of one‐dimensional metal‐dielectric photonic crystal
Authors: Fang Yun‐tuan , Chen Lin‐kun , Zhu Na , Zhou Jun
Published: March 2013

The authors employ the Bloch theorem of periodic structures and transfer matrix method to study the Tamm states supported in the surface of a semi‐infinite one‐dimensional (1D) metal‐dielectric photonic crystal (PC) that is adjacent to an air background. The authors find that the optical properties of the Tamm states are quite different between the transverse magnetic (TM) wave and electric (TE) wave. The Tamm state properties are also sensitive to the stack sequence of the PC. Owing to the surface plasmon resonance on the surface of metal, the Tamm states of 1D metal‐dielectric PC take on some unusual properties including the straight dispersion curve, extremely slow group velocity and large range of frequencies.
Radial distribution and axial dispersion of suspended particles inside a narrow cylinder due to mildly inertial flow
Authors: Bhattacharya S. , Gurung D. K. , Navardi S.
Published: March 2013

The combined effects of radial drift due to flow inertia and diffusion due to Brownian motion significantly modify the radial probability distribution and the axial dispersion of conduit-bound suspended bodies. This interplay depends on the product of Peclet Pe and Reynolds Re numbers so that even apparently non-Brownian systems with high Pe exhibit the changes if Re is small. This article describes the probability distribution and the Taylor dispersion coefficient under such conditions for systems with low vessel-to-particle size-ratios where the effect is especially pronounced, but the flow-simulation is considerably difficult. We also identify the parametric regimes and the physical conditions required to see a substantial manifestation of the effect.
Phase separation and direct magnetocaloric effect in La0.5Ca0.5MnO3 manganite
Authors: Amirzadeh P. , Ahmadvand H. , Kameli P. , Aslibeiki B. , Salamati H. , Gamzatov A. G. , Aliev A. M. , Kamilov I. K.
Published: March 2013

A series of phase separated La0.5Ca0.5MnO3 manganite samples with different grain sizes were studied by ac susceptibility, direct magnetocaloric effect (ΔT), and heat capacity measurements. The ac susceptibility shows that fractions of ferromagnetic and antiferromagnetic phases and consequently the phase separated state can be controlled by means of sintering temperature. Lower sintering temperature leads to a ferromagnetic state, while higher sintering temperature increases antiferromagnetic phase fraction, resulting in a phase separated state. In the phase separated samples, ΔT shows a conventional positive peak near TC and an anomalous positive peak at lower temperature near TN. The anomalous positive peak appears at higher magnetic field and is accompanied with thermal hysteresis. It is suggested that the anomalous magnetocaloric behaviors result from phase separation and first order magnetostructural phase transition. This study shows that direct magnetocaloric effect is a useful technique for the study of manganites.
Spike phase synchronization in delayed-coupled neural networks: Uniform vs. non-uniform transmission delay
Authors: Jalili Mahdi
Published: March 2013

In this paper, we investigated phase synchronization in delayed dynamical networks. Non-identical spiking Hindmarsh-Rose neurons were considered as individual dynamical systems and coupled through a number of network structures such as scale-free, Erdős–Rényi, and modular. The individual neurons were coupled through excitatory chemical synapses with uniform or distributed time delays. The profile of spike phase synchrony was different when the delay was uniform across the edges as compared to the case when it was distributed, i.e., different delays for the edges. When an identical transmission delay was considered, a quasi-periodic pattern was observed in the spike phase synchrony. There were specific values of delay where the phase synchronization reached to its peaks. The behavior of the phase synchronization in the networks with non-uniform delays was different with the former case, where the phase synchrony decreased as distributed delays introduced to the networks.
Induced magneto-electric coupling at ferroelectric/ferromagnetic interface
Authors: Carvell Jeffrey , Cheng Ruihua , Yang Q.
Published: March 2013

We have demonstrated that at room temperature the electric polarization of a ferroelectric polymer, polyvinylidene fluoride (PVDF), in an artificial multiferroic structure can be controlled by applying an external magnetic field. We found that as the applied magnetic field is changed, the switching of electric polarization for the PVDF depends on the external magnetic field. We also noticed that both the electric coercivity and polarization of the PVDF polymer display hysteretic features as the applied magnetic field is changed. We found that the thickness of the PVDF layer has an effect on the magnetoelectric coupling strength in our samples. The coupling sensitivity increases as the PVDF layer thickness increases. It is possible to control the ferroelectric properties of a PVDF film by tuning the external magnetic field.
Strain induced tunable anisotropic magnetoresistance in La0.67Ca0.33MnO3/BaTiO3 heterostructures
Authors: Xie Yali , Yang Huali , Liu Yiwei , Yang Zhihuan , Chen Bin , Zuo Zhenghu , Katlakunta Sadhana , Zhan Qingfeng , Li Run-Wei
Published: March 2013

In this paper, we investigated the influence of strain on anisotropic magnetoresistance (AMR) in La0.67Ca0.33MnO3 (LCMO) films epitaxially grown on BaTiO3(001). For 250-nm-thick LCMO film, the AMR shows a peak near the metal-insulator transition (MIT) temperature, which is similar to that in bulk LCMO. When the thickness of LCMO is decreased to 150 nm, the AMR value achieves a maximum at low temperature. For 80-nm-thick LCMO film, in addition to the appearance of the maximum AMR at low temperature, the symmetry and sign of AMR are also changed, associated with interface strain in the different phases of BaTiO3. In comparison, the AMR for the reference LCMO films grown on SrTiO3(001) shows a maximum value near the MIT temperature regardless of the thickness of film. Our experiment results suggest that not only the strain value but also the distortion type can considerably tune the AMR of LCMO films.
Improved multiferroic behavior in [111]-oriented BiFeO3/BiAlO3 superlattice
Authors: Ding Hang-Chen , Li Ya-Wei , Zhu Wanjiao , Gao Yong-Chao , Gong Shi-Jing , Duan Chun-Gang
Published: March 2013

We report a systematic study on the structural, electronic, magnetic, and ferroelectric properties of [111]-oriented BiFeO3/BiAlO3 (BFO/BAO) superlattice using density-functional calculations. It is found that the Fe-O-Fe superexchange interactions in BFO/BAO superlattice are greatly suppressed by the inserted BAO layers, with the antiferromagnetic-ferromagnetic transition energy decreasing from around 280 meV per BFO formula unit (five atoms) to 11.6 meV per BFO/BAO formula unit (ten atoms). The tensile strain can further decrease this energy, making the magnetic transition more plausible. In addition, we find that BFO/BAO superlattice preserves the large ferroelectric polarization as well as energy gap of bulk BFO. Therefore, BAO may be a good candidate for constructing the BFO-based superlattice with improved multiferroicity.
Three-dimensional mapping of the anisotropic magnetoresistance in Fe3O4 single crystal thin films
Authors: Ding Z. , Li J. X. , Zhu J. , Ma T. P. , Won C. , Wu Y. Z.
Published: March 2013

The anisotropic magnetoresistance (AMR) effect with a magnetic field along arbitrary directions in single crystalline (001)-oriented Fe3O4 films was studied. A cubic symmetry term, an in-plane uniaxial term, and an out-of-plane uniaxial term could be quantitatively separated. The cubic term is independent of the current direction, and decreases with increasing temperature, but both in-plane and out-of-plane uniaxial terms are found to be strongly dependent on the current orientation. This three-dimensional magnetoresistance measurement provides a quantitative method for identifying the different contributions to the AMR effect.
Large magnetic heat transport in a Haldane chain material Ni(C3H10N2)2NO2ClO4
Authors: Sun X. F. , Liu X. G. , Chen L. M. , Zhao Z. Y. , Zhao X.
Published: March 2013

We report a study on the heat transport of an S = 1 Haldane chain compound Ni(C3H10N2)2NO2ClO4 at low temperatures and in magnetic fields. The zero-field thermal conductivities show a remarkable anisotropy for the heat current along the spin-chain direction (κb) and the vertical direction (κc), implying a magnetic contribution to the heat transport along the spin-chain direction. The magnetic-field-induced change of the spin spectrum has obviously opposite impacts on κb and κc. In particular, κb(H) and κc(H) curves show peak-like increases and dip-like decreases, respectively, at ∼9 T, which is the critical field that minimizes the spin gap. These results indicate a large magnetic thermal transport in this material.
An alternate approach to the production of radioisotopes for nuclear medicine applications
Authors: D’Auria John M. , Keller Roderich , Ladouceur Keith , Lapi Suzanne E. , Ruth Thomas J. , Schmor Paul
Published: March 2013

There is a growing need for the production of radioisotopes for both diagnostic and therapeutic medical applications. Radioisotopes that are produced using the (n,γ) or (γ,n) reactions, however, typically result in samples with low specific activity (radioactivity/gram) due to the high abundance of target material of the same element. One method to effectively remove the isotopic impurity is electro-magnetic mass separation. An Ion Source Test Facility has been constructed at TRIUMF to develop high-intensity, high-efficiency, reliable ion sources for purification of radioactive isotopes, particularly those used in nuclear medicine. In progress studies are presented.
Magnetization reversal in antiferromagnetically coupled [Pt/CoFeB]N1/Ru/[CoFeB/Pt]N2 structures with perpendicular anisotropy
Authors: Xiao Yili , Chen Shaohai , Zhang Zongzhi , Ma Bin , Jin Q. Y.
Published: March 2013

Magnetic interlayer coupling and magnetization switching characteristics have been investigated in synthetic antiferromagnetically coupled [Pt/CoFeB]N1/Ru/[CoFeB/Pt]N2 structures with perpendicular anisotropy. We observe an oscillatory behavior of the antiferromagnetic coupling with a period of 0.7 nm and a maximum coupling strength of 0.09 erg/cm2. The coupling field is shown to decrease rapidly with the increase of repetition number and measurement temperature. Depending on the repetition numbers of the two multilayers, magnetic hysteresis loops may or may not display a reversal feature of the net magnetic moment. Samples with large N have a bow-tie loop shape due to the formation of multi-domains. The analysis of magnetic moments and exchange coupling fields show that there exists a ∼0.4 nm thick magnetic dead layer mostly at the CoFeB/Ru interface.
Fast tunable reflection in amorphous blue phase III liquid crystal
Authors: Chen Hui-Yu , Lai Jia-Liang , Chan Chun-Cheng , Tseng Chih-Han
Published: March 2013

The dynamic reflection spectra of amorphous blue phase III were investigated. When an electric field is applied to a blue phase III cell, the reflected wavelength does not shift obviously, but the intensity of reflection increases or decreases in a few ms. This fast intensity-tunable phenomenon in blue phase III relates to the dielectric anisotropies and chiralities of the liquid crystal and can be explained by the double twist model consisting of randomly orientated double-twisted cylinders. This study shows that blue phase III can act as a fast intensity-tunable reflector for a specific wavelength.
Effect of reduced dimensionality on the optical band gap of SrTiO3
Authors: Lee Che-Hui , Podraza Nikolas J. , Zhu Ye , Berger Robert F. , Shen Shaoping , Sestak Michelle , Collins Robert W. , Kourkoutis Lena F. , Mundy Julia A. , Wang Huiqiong , Mao Qingyun , Xi Xiaoxing , Brillson Leonard J. , Neaton Jeffrey B. , Muller David A. , Schlom Darrell G.
Published: March 2013

The effect of dimensional confinement on the optical band gap of SrTiO3 is investigated by periodically introducing one extra SrO monolayer every n SrTiO3 layers. The result is the n = 1–5 and 10 members of the Srn+1TinO3n+1 Ruddlesden-Popper homologous series. Spectroscopic ellipsometry, optical transmission, and cathodoluminescence measurements reveal these Srn+1TinO3n+1 phases to have indirect optical band gaps at room temperature with values that decrease monotonically with increasing n. First-principles calculations suggest that as n increases and the TiO6 octahedra become connected for increasing distances along the c-axis, the band edge electronic states become less confined. This is responsible for the decrease in band gaps with increasing n (for finite n) among Srn+1TinO3n+1 phases.
Optical phonon modes in InGaN/GaN dot-in-a-wire heterostructures grown by molecular beam epitaxy
Authors: Titus J. , Nguyen H. P. T. , Mi Z. , Perera A. G. U.
Published: March 2013

We report on the studies of optical phonon modes in nearly defect-free GaN nanowires embedded with intrinsic InGaN quantum dots by using oblique angle transmission infrared spectroscopy. These phonon modes are dependent on the nanowire fill-factor, doping densities of the nanowires, and the presence of InGaN dots. These factors can be applied for potential phonon based photodetectors whose spectral responses can be tailored by varying a combination of these three parameters. The optical anisotropy along the growth (c-) axis of the GaN nanowire contributes to the polarization agility of such potential photodetectors.
Magnetic properties of ordered bi-layer nanowire arrays with different Co crystallographic structures
Authors: Sellarajan B. , Kulkarni P. D. , Krishnan M. , Barshilia Harish C. , Chowdhury P.
Published: March 2013

Cobalt nanowire arrays with varying length were grown by pulse electrochemical route into the pores of alumina template. The structural investigation reveals that at the bottom of the nanowire, it grows with hcp (002) structure up to few hundred nanometer in length and then changes its crystal orientation to hcp (100) phase as it further grows along the wire axis. The variation of measured coercivity and the remanent ratio as a function of nanowire length indicate that each nanowire in array grows with three different segments. The micromagnetic simulations carried out on these structures are then correlated with experimental observations.
Reversible gold nanorod assembly triggered by pH-responsive DNA nanomachine
Authors: Zhao Dan , Zhang Zhiliang , Wen Yongqiang , Zhang Xueji , Song Yanlin
Published: March 2013

In this work, highly reversible end-to-end assembly of gold nanorods (AuNRs) has been achieved based on pH-responsive DNA nanomachine. In this system, the polyvalent linkages between AuNRs and duple cyclic disulfide group-modified DNA molecules tremendously enhanced the stability of the AuNRs-DNA conjugates. The excellent controllability and reproducibility of the assembly was demonstrated through consecutive assembly/disassembly cycles. This strategy is expected to be used for precise construction and manipulation of more complex functional nanodevices.
Design of Multiple Metal Doped Ni Based Catalyst for Hydrogen Generation from Bio-oil Reforming at Mild-temperature
Authors: Yuan Li-xia , Ding Fang , Yao Jian-ming , Chen Xiang-song , Liu Wei-wei , Wu Jin-yong , Gong Fei-yan , Li Quan-xin
Published: March 2013

A new kind of multiple metal (Cu, Mg, Ce) doped Ni based mixed oxide catalyst, synthesized by the co-precipitation method, was used for efficient production of hydrogen from bio-oil reforming at 250–500 °C. Two reforming processes, the conventional steam reforming (CSR) and the electrochemical catalytic reforming (ECR), were performed for the bio-oil reforming. The catalyst with an atomic mole ratio of Ni:Cu:Mg:Ce:Al=5.6:1.1:1.9:1.0:9.9 exhibited very high reforming activity both in CSR and ECR processes, reaching 82.8% hydrogen yield at 500 °C in the CSR, yield of 91.1% at 400 °C and 3.1 A in the ECR, respectively. The influences of reforming temperature and the current through the catalyst in the ECR were investigated. It was observed that the reforming and decomposition of the bio-oil were significantly enhanced by the current. The promoting effects of current on the decomposition and reforming processes of bio-oil were further studied by using the model compounds of bio-oil (acetic acid and ethanol) under 101 kPa or low pressure (0.1 Pa) through the time of flight analysis. The catalyst also shows high water gas shift activity in the range of 300–600 °C. The catalyst features and alterations in the bio-oil reforming were characterized by the ICP, XRD, XPS and BET measurements. The mechanism of bio-oil reforming was discussed based on the study of the elemental reactions and catalyst characterizations. The research catalyst, potentially, may be a practical catalyst for high efficient production of hydrogen from reforming of bio-oil at mild-temperature.
Vacuum Ultraviolet Photoionization and Dissociative Photoionization of Capecitabine, 5′-Deoxy-5-Fluorocytidine, and 5′-Deoxy-5-Fluorouridine
Authors: Wang Jian , Tang Wen-jian , Ye Li-li , Zhang Li-dong , Pan Yang
Published: March 2013

Vacuum ultraviolet (VUV) photoionization and dissociative photoionization of capecitabine and its metabolites, 5′-deoxy-5-fiuorocytidine (5′-DFCR) and 5′-deoxy-5- fluorouridine (5′-DFUR), were investigated with infrared laser desorption/tunable synchrotron VUV photoionization mass spectrometry. Molecular ions (M+) with small amounts of fragments can be found for these compounds at relatively low photon energies, while more fragment ions would be produced by increasing the photon energies. (M−H2O)+, (base+H)+, (base+2H)+, (base+30)+, (base+60)+, and sugar moiety were proposed for these nucleoside drugs with similar backbones. Decomposition channels for the major fragments were discussed in detail. Moreover, ab initio calculations were introduced to study the dehydration pathways of three fluoro-nucleosides. Corresponding appearance energies for the (M−H2O)+ ions were computed.
Potential Function and Thermodynamic Property of UO
Authors: Zeng Xiu-lin , Xu Si-yu , Ju Xue-hai
Published: March 2013

Potential energy scan for uranium oxide (UO) was performed by ab initio configuration interaction (CI) method and density functional theory methods at the PBE1 and the B3LYP levels in combination with the (ECP80MWB_AVQZ+2f) basis set for uranium and 6-311+G* for oxygen. The dissociation energies of UO, after being corrected for the zero-point vibrational energy, are 2.38, 3.76, and 3.31 eV at the CI, PBE1, and B3LYP levels, respectively. The calculated energy was fitted to potential functions of Morse, Lennard-Jones, and Rydberg. Only the Morse function is eligible for the potential. The anharmonicity constant is 0.00425. The anharmonic frequency is 540.95 cm−1 deduced from the PBE1 results. Thermodynamic properties of entropy and heat capacity at 298.2–1500 K were calculated using DFT-UPBE1 results and Morse parameters. The relationship between entropy and temperature was established.
Transformations and Tautomeric Equilibrium among Different Intermediates in Proline-Catalyzed Reactions of Aldehydes or Ketones
Authors: Gan Li-hua , Chang Qing , Zhou Jin
Published: March 2013

The enamines, iminium ions, and oxazolidinones are thought to be the key intermediates in the proline-catalyzed reactions of aldehydes or ketones, but there is an extensive controversy about their roles. Here, the corresponding transition states connecting any two of the three kinds of species are located at the ωB97XD/6-311++G** level of theory. The calculations demonstrate that the oxazolidinones are the predominant species in both the gas phase and solvents; there exists tautomeric equilibrium among these species and the equilibriums are controlled by the employed solvents and temperature in the reaction. These results demonstrate that the concentration and role of the mentioned species are controlled by the employed solvent and temperature. A new reaction pathway is presented herein for the transformation between iminium ions and oxazolidinones through iminium ion-water complex and oxazolidinone-water complex. The calculations demonstrate that the rate-limiting step in proline-catalyzed Mannich reaction between acetaldehyde/keteones and N-Boc imines is the formation of the C—C bond rather than the intermediates tautomerization. These calculations rationalize the available experimental observations and can be valuable in optimizing the experimental conditions of asymmetric organic-catalyzed reactions of aldehydes or ketones.
Efficient Coherent Population Transfer of D2 Molecules by Stark-Induced Adiabatic Raman Passage
Authors: Wang Tao , Yang Tian-gang , Xiao Chun-lei , Dai Dong-xu , Yang Xue-ming
Published: March 2013

Preparation of a high flux of hydrogen molecules in a specific vibrationally excited state is the major prerequisite and challenge in scattering experiments that use vibrationally excited hydrogen molecules as the target. The widely used scheme of stimulated Raman pumping suffers from coherent population return which severely limits the excitation efficiency. Recently we successfully transferred D2 molecules in the molecular beam from (υ=0, J=0) to ( υ=1, J=0) level, with the scheme of Stark-induced adiabatic Raman passage. As high as 75% of the excitation efficiency was achieved. This excitation technique promise to be a unique tool for crossed beam and beam-surface scattering experiments which aim to reveal the role of vibrational excitation of hydrogen molecules in the chemical reaction.
Direct Synthesis of High Purity Silicon Wires by Electrorefining in Molten KF-NaF Eutectic
Authors: Zou Xiang-yu , Xie Hong-wei , Zhai Yu-chun , Lang Xiao-chuan
Published: March 2013

The electrochemical synthesis silicon wires by electrorefining metallurgical grade silicon in thermally dried and pre-electrolyzed molten KF-NaF eutectic were studied at temperatures 800–900 °C using cyclic voltammetry and ac impedance. One oxidation peak at −0.14 V could be attributed to the reaction of Si to Si4+. A cathodic peak occurred at −0.56 V in the cyclic voltammogram and one response semicircle in the ac impedance spectrum was observed, supporting a one-step electrochemical reduction process of Si4+→Si. The electrochemical reaction of silicon was controlled by the diffusion process. The purity of electrorefined silicon wires was up to 99.999% by ICP-MS analysis.
Self-Assembly and UV-Curing Property of Polymerized Lyotropic Liquid Crystal Monomer of Sodium 3,4,5-tris(11-acryloxyundecyloxy)benzoate
Authors: Bai Yu-qin , Guo Jin-bao , Wang Ying , Wei Jie
Published: March 2013

A polymerized lyotropic liquid crystal monomer of sodium 3,4,5-tris(11-acryloxyundecyloxy)-benzoate was synthesized by a convenient route starting from 3,4,5-trihydroxybenzoic acid via esterification followed by etherification, acylation and finally neutralization. The chemical structure was confirmed by Fourier transform infrared (FT-IR) and H1 nuclear magnetic resonance spectral analysis. The self-organization behavior of the monomer with deionized water in methanol at room temperature was also demonstrated. The assemblies were characterized by polarized optical microscope and X-ray diffraction. The results show that a solution containing 80:20 of the monomer to water was found to be able to self-organize into Lamellar (La) phase and 92:8 with inverted hexagonal (HII) phase, which was in accordance with the theoretical calculation of critical packing parameter. It suggests that the concentration of the monomer was the key factor to influence assembly structure. Additionally, the acrylate conversion with different photoinitiators and nanostructure retention after polymerization were investigated. The research shows that the acrylate conversion of the monomer with Darocur2959 could reach up to 78% when irradiated by 30 mW/cm2 UV light of 365 nm for 30 min characterized by Real-time FT-IR as well as the sol-gel method. Meanwhile, the La and HII phase nanostructures were both retained after polymerization.
Age, growth and reproductive biology of the spot-tail shark, Carcharhinus sorrah, and the Australian blacktip shark, C. tilstoni, from the Great Barrier Reef World Heritage Area, north-eastern Australia
Authors: Harry Alastair V. , Tobin Andrew J. , Simpfendorfer Colin A.
Published: March 2013

Understanding the life history of an exploited fish species is an integral part of successful fisheries management and this information can be used in quantitative population assessments. The present study describes the quantitative relationships among age, growth and reproductive biology of two commercially exploited sharks from the Great Barrier Reef World Heritage Area (GBRWHA), namely, the spot-tail shark, Carcharhinus sorrah (n = 659) and the Australian blacktip shark, C. tilstoni (n = 512). Longevity estimates based on vertebral ageing were 9 and 14 years for male and female C. sorrah and 13 and 15 years for C. tilstoni. However, an age-validation study failed to validate annual banding in larger individuals, suggesting that maximum age may be underestimated by vertebrae. C. sorrah grew to adult size relatively fast, reaching maturity at 2.3–2.4 years, whereas C. tilstoni grew slower, reaching maturity at 5.2–6.1 years. For both species, however, reproduction did not commence until approximately a year after maturity, at 3.4 years for C. sorrah and 7.2 years for C. tilstoni. The results of the present study suggest that in the GBRWHA, C. tilstoni, in particular, begins reproducing at an older age and lives longer than previously thought.
Potential for genetic improvement of silkworm through molecular and transgenic approaches.
Authors: Zhao AiChun Zhao AiChun , Zhang Yang Zhang Yang , Long DingPei Long DingPei
Published: March 2013

The silkworm (
Bombyx mori
) makes a great contribution to agricultural development, but traditional breeding is constrained by limited natural genetic resources. Transgenic technologies bring a new opportunity for the genetic improvement of silkworm. This review focuses on the improvement of genetically modified silk, the production of recombinant proteins and resistance breeding by transgenic silkworms and new molecular approaches. The potential of using transgenic silkworm as a tool for producing biomaterials and as a bioreactor for producing recombinant proteins is also discussed.
Two structural components in CNGA3 support regulation of cone CNG channels by phosphoinositides
Authors: Dai Gucan , Peng Changhong , Liu Chunming , Varnum Michael D.
Published: March 2013

Cyclic nucleotide-gated (CNG) channels in retinal photoreceptors play a crucial role in vertebrate phototransduction. The ligand sensitivity of photoreceptor CNG channels is adjusted during adaptation and in response to paracrine signals, but the mechanisms involved in channel regulation are only partly understood. Heteromeric cone CNGA3 (A3) + CNGB3 (B3) channels are inhibited by membrane phosphoinositides (PIPn), including phosphatidylinositol 3,4,5-triphosphate (PIP3) and phosphatidylinositol 4,5-bisphosphate (PIP2), demonstrating a decrease in apparent affinity for cyclic guanosine monophosphate (cGMP).

Unlike homomeric A1 or A2 channels, A3-only channels paradoxically did not show a decrease in apparent affinity for cGMP after PIPn application. However, PIPn induced an ∼2.5-fold increase in cAMP efficacy for A3 channels. The PIPn-dependent change in cAMP efficacy was abolished by mutations in the C-terminal region (R643Q/R646Q) or by truncation distal to the cyclic nucleotide-binding domain (613X). In addition, A3-613X unmasked a threefold decrease in apparent cGMP affinity with PIPn application to homomeric channels, and this effect was dependent on conserved arginines within the N-terminal region of A3. Together, these results indicate that regulation of A3 subunits by phosphoinositides exhibits two separable components, which depend on structural elements within the N- and C-terminal regions, respectively. Furthermore, both N and C regulatory modules in A3 supported PIPn regulation of heteromeric A3+B3 channels. B3 subunits were not sufficient to confer PIPn sensitivity to heteromeric channels formed with PIPn-insensitive A subunits. Finally, channels formed by mixtures of PIPn-insensitive A3 subunits, having complementary mutations in N- and/or C-terminal regions, restored PIPn regulation, implying that intersubunit N–C interactions help control the phosphoinositide sensitivity of cone CNG channels.
Lack of negative slope in I-V plots for BK channels at positive potentials in the absence of intracellular blockers
Authors: Geng Yanyan , Wang Xiaoyu , Magleby Karl L.
Published: March 2013

Large-conductance, voltage- and Ca2+-activated K+ (BK) channels display near linear current–voltage (I-V) plots for voltages between −100 and +100 mV, with an increasing sublinearity for more positive potentials. As is the case for many types of channels, BK channels are blocked at positive potentials by intracellular Ca2+ and Mg2+. This fast block progressively reduces single-channel conductance with increasing voltage, giving rise to a negative slope in the I-V plots beyond about +120 mV, depending on the concentration of the blockers. In contrast to these observations of pronounced differences in the magnitudes and shapes of I-V plots in the absence and presence of intracellular blockers, Schroeder and Hansen (2007. J. Gen. Physiol. http://dx.doi.org/10.1085/jgp.200709802) have reported identical I-V plots in the absence and presence of blockers for BK channels, with both plots having reduced conductance and negative slopes, as expected for blockers. Schroeder and Hansen included both Ca2+ and Mg2+ in the intracellular solution rather than a single blocker, and they also studied BK channels expressed from α plus β1 subunits, whereas most previous studies used only α subunits. Although it seems unlikely that these experimental differences would account for the differences in findings between previous studies and those of Schroeder and Hansen, we repeated the experiments using BK channels comprised of α plus β1 subunits with joint application of 2.5 mM Ca2+ plus 2.5 mM Mg2+, as Schroeder and Hansen did. In contrast to the findings of Schroeder and Hansen of identical I-V plots, we found marked differences in the single-channel I-V plots in the absence and presence of blockers. Consistent with previous studies, we found near linear I-V plots in the absence of blockers and greatly reduced currents and negative slopes in the presence of blockers. Hence, studies of conductance mechanisms for BK channels should exclude intracellular Ca2+/Mg2+, as they can reduce conductance and induce negative slopes.
Older and younger workers: the equalling effects of health
Authors: Beck Vanessa , Quinn Martin
Published: March 2013

Purpose

The purpose of this paper is to consider the statistical evidence on the effects that ill health has on labour market participation and opportunities for younger and older workers in the East Midlands (UK).

Design/methodology/approach

A statistical analysis of Labour Force Survey data was undertaken to demonstrate that health issues affect older and younger workers alike. This has an equalling effect on labour market opportunities, which should reduce any potential for intergenerational conflict within the workforce.

Findings

Although health problems that limit activities and affect the amount and kind of work an individual can undertake increase with age, there are high levels of ill health of these kinds within all age groups, including the youngest workers.

Research limitations/implications

The regional statistical analysis can only provide indications, and further research is required to differentiate which groups of younger and older workers suffer from which types of illnesses, as this has direct implications for their employment.

Practical implications

A more direct consideration of health in employment, education and training policy is required to enable the development of healthy and long‐term working lives that benefit individuals and the economy.

Social implications

The consideration of the effects of health issues on the labour market should lead to a reconsideration of the rhetoric, and the reality of intergenerational conflict. There might be less reason for such competition than is generally perceived.

Originality/value

The paper considers intergenerational conflict in a labour market context and suggests that health issues have an equalising effect for the relative positions of older and younger workers.
Entrepreneurship education
Authors: Marques Carla S. , Ferreira João J. , Gomes Daniela N. , Gouveia Rodrigues Ricardo
Published: March 2013

Purpose

Based on the Theory of Planned Behaviour (TPB), the purpose of this paper is to approach entrepreneurial intention (EI) and the factors preceding the founding of EI among secondary students, both studying general academic and specific professional programs, and thereby establish causal relationships between psychological, demographic and behavioural factors.

Design/methodology/approach

A sample of secondary students, both studying general academic and specific professional programs, was chosen. Data were collected through questionnaires and analysed with resource to structural equation models (SEM) to measure the causal relationships among different constructs.

Findings

The results show that the EI of secondary school students is influenced by such demographic, psychological and behavioural factors. However, the hypothesis of becoming entrepreneurs in the future remains independent of the fact of whether or not students had already experienced engagement with entrepreneurship‐related themes having no impact on EI. These results raise a series of pertinent questions and deserve being subject to a more profound reflection and not only among the scientific and academic community but also among political and government entities.

Originality/value

The paper provides important evidence to expand entrepreneurship education specifically in the field of secondary school education. These students are already about to face choices over their professional careers. This remains valid whether or not students intend to proceed with higher education studies or to join the workforce. Therefore this research contributes towards meeting a better understanding of EI and the factors preceding the formation of this intention among secondary school students.
Readiness towards entrepreneurship education
Authors: Othman Norasmah , Hashim Norashidah , Ab Wahid Hariyaty
Published: March 2013

Purpose

The purpose of this paper is to observe the readiness of students and the internal environment of Malaysian public universities in the implementation of entrepreneurship education.

Design/methodology/approach

The authors employed a quantitative approach and the main instrument used to gauge the entrepreneurship readiness among students in Malaysia public universities was the questionnaire. The data were analysed using Statistical Package for Social Sciences (SPSS) software to obtain descriptive statistics that describe the profile of entrepreneurship readiness, both among the students themselves and in the internal environment of the universities, as the students perceive it.

Findings

According to the findings, students in Malaysian public universities demonstrate strong readiness, in terms of entrepreneurial willingness and capabilities. Within the internal environment of public universities, however, readiness for entrepreneurship education remains, from the students’ perspective, imperfect, and requires improvement if these institutions are to support future entrepreneurship education.

Research limitations/implications

This research is limited to students in Malaysian public universities. It is suggested that further research should include the students of private universities also, in order to mine a wealth of information pertinent to the readiness of Malaysian students, as well as to provide material for the remodelling of the internal environments of higher learning institutions.

Practical implications

Readiness profiles of students and institutions towards the implementation of entrepreneurship education provide important resources for policymakers responsible for Malaysian public universities, enabling them to enhance the implementation of entrepreneurship education.

Originality/value

There has been little discussion or analysis of the readiness of students and the internal environments of public universities in Malaysia towards the implementation of entrepreneurship education. This paper attempts to fill this gap in current research.
Enterprise education: for all, or just some?
Authors: Jones Colin , Matlay Harry , Maritz Alex
Published: March 2013

Purpose

The purpose of this paper is to provocatively enter four imagined worlds of enterprise education with the express aim of contemplating an emerging future. The authors do so not to expressly determine what positioning is most appropriate for enterprise/entrepreneurship education, but rather to consider the issues associated with each of the four imagined worlds.

Design/methodology/approach

The authors’ approach is built around a combination of cycles of reflective practice and the use of scenario development processes. The authors seek to suspend their collective judgement whilst entering the four imagined worlds, but ultimately do not claim to have hidden their personal biases.

Findings

It is concluded that enterprise/entrepreneurship education should be shared across the university and not owned by any school or faculty. While the authors find it difficult to dismiss the underlying purpose of each scenario, they sense an opportunity to unite their common focus on the development of a transformative student experience.

Practical implications

This process has provided unexpected insights into the potential of scenario planning as a tool that could conceivably be employed more often to tackle complex issues, such as the positioning of enterprise/entrepreneurship education in Higher Education.

Originality/value

This paper, despite its inherent biases, offers the reader an opportunity to gain a sense of the various roles forced upon enterprise/entrepreneurship education by its various key stakeholders. In doing so, the shortcomings of the current situation are highlighted.
Increasing learners’ satisfaction/intention to adopt more e‐learning
Authors: Sawang Sukanlaya , Newton Cameron , Jamieson Kieren
Published: March 2013

Purpose

E‐learning is an organizationally risky investment given the cost and poor levels of adoption by users. In order to gain a better understanding of this problem, the aim of this paper is to conduct a study into the use of e‐learning in a rail organization.

Design/methodology/approach

Using an online survey, employees of a rail‐sector organization were questioned about their use and likelihood of adoption of e‐learning. This study explores the factors that affect the way in which learners experience and perceive such systems. Using statistical analysis, 12 hypotheses are tested and explored. Relationships between learning satisfaction, intention to adopt, and the characteristics of e‐learning systems were established.

Findings

The study found that e‐learning characteristics can buffer the relationship between learner characteristics and intention to adopt further e‐learning in the future. Further, the paper found that high levels of support can compensate individuals who are low in technological efficacy to adopt e‐learning.

Research limitations/implications

The cross‐sectional design of the study and its focus on measuring intention to adopt as opposed to actual adoption are both limitations. Future research using longitudinal design and research employing a time lag design measuring actual adoption as well as intention are recommended.

Practical implications

From a practical perspective, organizations can focus on the actual content and authenticity of the learning experience delivered by the e‐learning system to significantly impact how employees will perceive and use e‐learning in the future. Low technological efficacy individuals tend not to adopt new technology. Instead of changing individuals’ personalities, organizations can implement supportive policies and practices which would lead to higher e‐learning adoption rate among low efficacy individuals.

Originality/value

The study integrates technology adoption and learning literatures in developing enablers for e‐learning in organizations. Further, this study collects data from rail employees, and therefore the findings are practical to an industry.
The effects of core self‐evaluations and transformational leadership on organizational commitment
Authors: Joo Baek‐Kyoo (Brian) , Jun Yoon Hea , Jeung Chang‐Wook
Published: March 2013

Purpose

The purpose of this study is to examine the joint effects of employees’ core self‐evaluations and perceived transformational leadership of their supervisors on employees’ affective commitment to the organization.

Design/methodology/approach

Subjects were drawn from aFortuneGlobal 500 company in Korea. Descriptive statistics and hierarchical multiple regression analyses were used to explain the variance in organizational commitment.

Findings

Core self‐evaluations and transformational leadership positively influenced employees’ organizational commitment. In terms of effect size, organizational commitment was more related to transformational leadership than core self‐evaluations. As for transformational leadership, employees exhibited the highest organizational commitment when their leaders articulated the vision, promoted group goals, and provided intellectual stimulation.

Research limitations/implications

The sample of this study is likely restricted to a certain group with similar demographic characteristics (e.g. male junior managers with relatively high education levels). This study, like most organizational commitment studies, relied on self‐reported and cross‐sectional survey method.

Practical implications

Since core self‐evaluations tend to be stable over time, HR professionals need to recruit and select those with higher core self‐evaluations. HR/OD professionals can help managers change their leadership in a transformative fashion (vision articulation, group goal promotion, and intellectual stimulation) by providing relevant training programs and developmental relationships such as coaching and mentoring.

Originality/value

This study took an integrative approach that encompasses personal and contextual factors in a study. It found not only a significant relationship between core self‐evaluations and organizational commitment, but also the interaction effects of core self‐evaluations and one of the dimensions of transformational leadership.
Relationships of leader reward behavior with employee behavior
Authors: Jackson Erin M. , Rossi Michael E. , Rickamer Hoover E. , Johnson Russell E.
Published: March 2013

Purpose

The purpose of this paper is to examine employee perceptions of fairness and work morale as mediators of the relationship between leader reward behavior and employee behavior.

Design/methodology/approach

A matrix of meta‐analytic estimates containing the focal variables (leader reward behavior, fairness, morale, and employee behavior) was constructed following a literature review of published studies. This matrix was then analyzed using structural equation modeling to test a series of nested models.

Findings

Leader reward behavior is positively related to higher task performance and organizational citizenship behavior, and fewer intentions to turnover. These relationships are mediated by employees’ perceptions of fairness and work morale.

Research limitations/implications

The paper extends the leadership literature by identifying two mechanisms (viz., fairness and morale) through which leader reward behavior relates to employee behavior. Possible limitations are the drawbacks associated with meta‐analysis (e.g. inability to make causal inferences).

Practical implications

Rewarding subordinate performance alone is not sufficient to increase task performance and organizational citizenship behavior and decrease turnover intentions. Instead, managers must ensure that their contingent reward behaviors are seen as fair by employees in order to have favorable effects.

Originality/value

To date, research on possible mediators of the effects of leader reward behavior has been scarce.