bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface characterization and functionalization of carbon nanofibers
Authors: Klein K. L. , Melechko A. V. , McKnight T. E. , Retterer S. T. , Rack P. D. , Fowlkes J. D. , Joy D. C. , Simpson M. L.
Published: March 2008

Carbon nanofibers are high-aspect ratio graphitic materials that have been investigated for numerous applications due to their unique physical properties such as high strength, low density, metallic conductivity, tunable morphology, chemical and environmental stabilities, as well as compatibility with organochemical modification. Surface studies are extremely important for nanomaterials because not only is the surface structurally and chemically quite different from the bulk, but its properties tend to dominate at the nanoscale due to the drastically increased surface-to-volume ratio. This review surveys recent developments in surface analysis techniques used to characterize the surface structure and chemistry of carbon nanofibers and related carbon materials. These techniques include scanning probe microscopy, infrared and electron spectroscopies, electron microscopy, ion spectrometry, temperature-programed desorption, and atom probe analysis. In addition, this article evaluates the methods used to modify the surface of carbon nanofibers in order to enhance their functionality to perform across an exceedingly diverse application space.
Electronic couplings and on-site energies for hole transfer in DNA: Systematic quantum mechanical/molecular dynamic study
Authors: Voityuk Alexander A.
Published: March 2008

The electron hole transfer (HT) properties of DNA are substantially affected by thermal fluctuations of the π stack structure. Depending on the mutual position of neighboring nucleobases, electronic coupling V may change by several orders of magnitude. In the present paper, we report the results of systematic QM/molecular dynamic (MD) calculations of the electronic couplings and on-site energies for the hole transfer. Based on 15ns MD trajectories for several DNA oligomers, we calculate the average coupling squares ⟨V2⟩ and the energies of basepair triplets XG+Y and XA+Y, where X, Y=G, A, T, and C. For each of the 32 systems, 15 000 conformations separated by 1ps are considered. The three-state generalized Mulliken–Hush method is used to derive electronic couplings for HT between neighboring basepairs. The adiabatic energies and dipole moment matrix elements are computed within the INDO/S method. We compare the rms values of V with the couplings estimated for the idealized B-DNA structure and show that in several important cases the couplings calculated for the idealized B-DNA structure are considerably underestimated. The rms values for intrastrand couplings G-G, A-A, G-A, and A-G are found to be similar, ∼0.07eV, while the interstrand couplings are quite different. The energies of hole states G+ and A+ in the stack depend on the nature of the neighboring pairs. The XG+Y are by 0.5eV more stable than XA+Y. The thermal fluctuations of the DNA structure facilitate the HT process from guanine to adenine. The tabulated couplings and on-site energies can be used as reference parameters in theoretical and computational studies of HT processes in DNA.
Size extensivity of the direct optimized effective potential method
Authors: Heaton-Burgess Tim , Cohen Aron J. , Yang Weitao , Davidson Ernest R.
Published: March 2008

We investigate the size extensivity of the direct optimized effective potential procedure of Yang and Wu [Phys. Rev. Lett. 89, 143002 (2002)]. The choice of reference potential within the finite basis construction of the local Kohn–Sham potential can lead to a method that is not size extensive. Such a situation is encountered when one employs the Fermi–Amaldi potential, which is often used to enforce the correct asymptotic behavior of the exact exchange-correlation potential. The size extensivity error with the Fermi–Amaldi reference potential is shown to behave linearly with the number of electrons in the limit of an infinite number of well separated monomers. In practice, the error tends to be rather small and rapidly approaches the limiting linear behavior. Moreover, with a flexible enough potential basis set, the error can be decreased significantly. We also consider one possible reference potential, constructed from the van Leeuwen–Baerends potential, which provides a size extensive implementation while also enforcing the correct asymptotic behavior.
Hysteresis-type current-voltage characteristics of indium tin oxide/poly (3,4-ethylenedioxythiophene) doped with poly (4-styrenesulfonate)/indium tin oxide devices
Authors: Lin Yow-Jon
Published: March 2008

In this study, electrical characteristics of indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene) doped with poly(4-styrenesulfonate) (PEDOT:PSS)/ITO devices have been investigated. The current-voltage (I-V) characteristics of devices show hysteresis behavior, and the hysteresis is formally described by different voltage amplitudes for the sweep from negative to positive bias and the reverse direction. According to the experimental results, the author suggested that donorlike trap states within the PEDOT:PSS layer controlled carrier flow and resulted in hysteresis-type I-V characteristics of ITO/PEDOT:PSS/ITO devices.
The role of lattice mismatch and kinetics in texture development: Co1−xNixSi2 thin films on Si(100)
Authors: Smeets D. , Vantomme A. , De Keyser K. , Detavernier C. , Lavoie C.
Published: March 2008

Mixed Co1−xNixSi2 films (0≤x≤1) were grown by solid phase reaction of homogeneous Co1−xNix metal films, codeposited on Si(100). The texture of these films was contemplated using complementary experimental techniques: Rutherford backscattering and channeling spectrometry, x-ray pole figure measurements, and orientation imaging with electron backscattering diffraction. Based on the increasing Co1−xNixSi2 lattice parameter with increasing Ni concentration, a gradual, continuous improvement of the epitaxial quality of the film would be expected. The observed trend is significantly different. The epitaxial quality of the disilicide film indeed improves with increasing Ni concentration, but only up to 15% Ni. Moreover, the increasing epitaxial quality is due to a large volume fraction of (110)-oriented grains, instead of the anticipated (100) orientation. The most abundant texture component is not necessarily the one with the best in-plane match with the substrate, i.e., epitaxy, nor the one which assures the continuity of crystallographic planes across the plane of the interface, i.e., axiotaxy. Clearly, geometrical arguments alone cannot account for the observed large size and high volume fraction of (110)-oriented grains. On the other hand, we demonstrate that growth kinetics plays an important role in texture development and epitaxial growth during the solid phase reaction. Above 15% Ni, the epitaxial quality rapidly decreases and a polycrystalline film is formed for 40% Ni. This decrease is explained by a gradual shift of the disilicide nucleation site from the interface with the substrate to the surface of the thin film. For high Ni concentrations, i.e., ≥50% Ni, the (100) orientation dominates the thin-film texture, due to the growth of a NiSi2-rich film at the substrate interface. The changing nucleation site, due to this phase separation, and the differing growth kinetics can significantly alter the texture of ternary films. These two factors should be taken into consideration when implementing ternary alloys in devices, since their physical properties, stability, roughness, resistance, etc., depend critically on the texture of the films.
Orange-red luminescence from Cu doped CdS nanophosphor prepared using mixed Langmuir–Blodgett multilayers
Authors: Mandal P. , Talwar S. S. , Major S. S. , Srinivasa R. S.
Published: March 2008

Cu doped CdS nanophosphors were fabricated through Langmuir–Blodgett route for the first time. Precursors mixed Langmuir–Blodgett multilayers of cadmium arachidate–copper arachidate were used to grow doped sulfide nanoparticles within the organic matrix through postdeposition treatment with H2S gas. Changes in composition and layered structure of precursor multilayers were studied using Fourier transform infrared and x-ray reflection. Uptake of Cu in the multilayers was analyzed by inductively coupled plasma atomic emission spectroscopy measurements. Unannealed H2S exposed multilayers containing CdS nanoparticles show strong surface state emission centeredat ∼570nm, whereas Cu doped CdS nanoparticles show orange-red luminescence. Photoluminescence (PL) spectra of annealed-Cu doped CdS nanoparticles show distinct Cu-related emission compared to annealed-undoped CdS nanoparticles. Power dependent PL measurements of annealed samples show that an efficient carrier recombination takes place at T2 level of Cu++. The carrier relaxation from the excitonic states to T2 level results in the strong orange-red luminescence.
An alternative near-neighbor definition of hydrogen bonding in water
Authors: Hammerich A. D. , Buch V.
Published: March 2008

A definition of hydrogen bonding in water is proposed in which an H⋯O pair forms a hydrogen bond if (a) an oxygen atom is the nearest nonchemically bonded neighbor of a hydrogen atom; and (b) the hydrogen is the first or the second intermolecular near-neighbor of the oxygen. Unlike the commonly employed hydrogen-bond definitions, this definition does not depend on the choice of geometric or energetic cutoffs applied to continuous distributions of properties. With the present definition, the distribution of O⋯H bond lengths decays smoothly to zero in a physically reasonable range. After correction for the presence of intermittent hydrogen bonds, this definition appears to provide a more stable description of hydrogen bonds and coordination shells than the more conventional cutoff-based definition. “Partial” H bonds satisfying only one of the two bonding requirements serve as transition states in the H-bond network evolution.
Quantum studies of light particle trapping, sticking, and desorption on metal and graphite surfaces
Authors: Medina Zuleika , Jackson Bret
Published: March 2008

A quantum mechanical formalism capable of describing the scattering, trapping, sticking, and desorption of an atom from a moving corrugated surface is presented. While the instantaneous particle-bath interaction is assumed to be weak, the particle and the bath can exchange energy over long periods of time. We have explored the trapping desorption and trapping-relaxation-sticking of He on Cu(110) and of H on graphite(0001). Higher substrate temperatures generally lead to increased trapping, but a higher desorption rate eventually leads to less, or zero sticking, at long times. In both cases, we observe that trapping in diffraction-mediated selective adsorption resonances can enhance sticking at low incident energies. While trapped in the resonance, the atom can relax toward the ground state of the gas-substrate attractive well. If the binding energy is larger than the amount of energy in the atom’s motion parallel to the surface, it remains stuck at long times, at sufficiently low temperatures. We find sticking probabilities on the order of 1% at very low energies for both systems. In the vicinity of a selective adsorption resonance, this sticking can increase by several percent, depending on the size of the corrugation.
Photochemical switching of ultrathin PbTiO3 films
Authors: Takahashi R. , Grepstad J. K. , Tybell T. , Matsumoto Y.
Published: March 2008

The ferroelectric domain ground state of PbTiO3 thin films on Nb:SrTiO3 substrates has been studied as a function of film thickness. High resolution linear Qx x-ray diffraction profiles were recorded in order to probe the presence of stripe domains, which were invariably observed for as-grown samples. After photochemical treatment, films thinner than 50 unit cells were switched to a monodomain state that could be reversed upon subsequent annealing. The stripe-domain state is linked to a Qx modulation of the Qz parameter in the reciprocal space, which disappears upon switching.
Extending the dynamic range of nuclear pulse spectrometers
Authors: Pullia A. , Zocca F. , Pascovici G. , Bazzacco D.
Published: March 2008

Using an innovative time-varying front-end electronics in conjunction with a bulky coaxial high-purity germanium detector, we were able to extend the range of the radionuclide spectra well beyond the analog to digital converter (ADC) saturation point. The electronics automatically conditions the signal for digital-filtering optimization if it is in the ADC voltage range and for time-over-threshold analysis if it exceeds the ADC range. A high spectroscopic resolution has been achieved in both operation ranges. An unprecedented wide energy range from 5keVto150MeV of equivalent energy, or 90dB, has been obtained using a single acquisition chain, while maintaining a high-energy resolution in the whole spectrum. For example, with an ADC range of 3MeV a resolution has been obtained of 1.3∕2.2keV full width at half maximum on the 122∕1332keV gamma-ray lines of Co57 and Co60, and of <0.4% in the time-over-threshold region, or for energy deposits beyond 3MeV.
Investigation of the occupation behavior for oxygen atoms in AlN films using Raman spectroscopy
Authors: McCullen E. F. , Thakur J. S. , Danylyuk Y. V. , Auner G. W. , Rosenberger L. W.
Published: March 2008

We investigated the behavior of Raman modes for AlN thin films fabricated with plasma source molecular beam epitaxy method having high levels of oxygen contamination. Oxygen atoms occupy different lattice sites depending on their at. % value and, thus, strongly influence spectral features of certain Raman modes. We studied the variations in the width of nonpolar E2low and E2high modes which represent mainly the vibrations of Al sublattice and N atoms, respectively, in the AlN lattice. When oxygen occupies a N site, it affects the width of the E2high mode, and at the same time, the charge neutrality constraint creates an Al vacancy and, thus, simultaneously affects the width of the E2low mode. We found that for our films whose oxygen concentration vary from 1to10at.%, the width of both the E2high and E2low modes varies linearly with the oxygen contamination levels suggesting that even at such high levels of oxygen contamination, oxygen atoms still prefer to occupy the N site. This is contrary to previous studies of single crystal AlN. The oxygen contamination in our films was determined by x-ray photoemission spectroscopy measurements.
Growth of graphene structure on 6H-SiC(0001): Molecular dynamics simulation
Authors: Tang Chao , Meng Lijun , Xiao Huaping , Zhong Jianxin
Published: March 2008

The growth process of graphene structure on 6H-SiC(0001) surface has been studied using the classical molecular dynamics simulation and the simulated annealing technique. Effects of annealing temperature and coverage of carbon atoms on the formation of graphene have been investigated. We found that two layers of carbon atoms of the 6H-SiC(0001) subsurface after sublimation of Si atoms undergo a transformation from a diamondlike phase to a graphenelike structure at annealing temperature above 1500K. This transformation temperature is in good agreement with experimental observations. We also found that the formation of graphene structure strongly depends on the number of carbon layers. Two layers of carbon atoms result in large graphene clusters and four layers of carbon lead to the formation of graphene bilayer sheets. However, a single layer of carbon only forms chainlike and ringlike clusters without the hexagonal ordering. Our results provide atomic-level information about the graphitization of the 6H-SiC(0001) surface, which is useful in controlling the growth of graphene sheets.
Wide-band acoustic collimating by phononic crystal composites
Authors: Shi Jinjie , Lin Sz-Chin Steven , Huang Tony Jun
Published: March 2008

We numerically investigated the collimation phenomena in phononic crystal (PC) composites, a sequenced series of PCs with the same period but different filling ratios. The plane wave expansion (PWE) method was used to obtain the band diagrams and the equal frequency surfaces of both single PCs and PC composites. The finite difference time domain (FDTD) method was then utilized to simulate the propagation of acoustic waves inside a PC composite. The results from both PWE calculations and FDTD simulations show that in comparison to a single PC, a PC composite can significantly enlarge the collimation region and realize wide-band acoustic collimation.
A solid phase reaction between TiCx thin films and Al2O3 substrates
Authors: Persson P. O. Å. , Rosen J. , McKenzie D. R. , Bilek M. M. M. , Höglund C.
Published: March 2008

Ti C x thin films were deposited on Al2O3 substrates at 900°C by using a multiple cathode high current pulsed cathodic arc. The Ti:C pulse ratio and, hence, the composition was varied from C rich to Ti rich. It is found that the Al2O3 substrate is decomposed and reacts with the TiCx film to incorporate significant amounts of O and Al in the growing film. When the stoichiometry is suitable, epitaxially oriented Ti2AlC MAX phase with significant O incorporated is formed. The results indicate that Al2O3 is not an ideal substrate material for the growth of transition metal carbides and MAX phase thin films.
Phase change memory based on Ge2Sb2Te5 capped between polygermanium layers
Authors: Zhang Ting , Song Zhitang , Gong Yuefeng , Lin Yun , Xu Cheng , Chen Yifeng , Liu Bo , Feng Songlin
Published: March 2008

The effects of polygermanium interlayer, acting mainly as heating and thermal-resisting one, on performance of phase change memory are studied. Thermal simulation shows that the maximum temperature in Ge2Sb2Te5 layer is remarkably promoted when Ge2Sb2Te5 is capped between polygermanium layers. The maximum temperature location moves closer to the interface between Ge2Sb2Te5 and tungsten plug, significantly avoiding the parallel resistance in the reset state, which makes the memory more reliable. Electrical measurement shows that the polygermanium capped structure has a much lower reset current and larger resistance contrast compared to the one without polygermanium layers.
Ni
O
∕
Zn
O
light emitting diodes by solution-based growth
Authors: Xi Y. Y. , Hsu Y. F. , Djurišić A. B. , Ng A. M. C. , Chan W. K. , Tam H. L. , Cheah K. W.
Published: March 2008

Heterojunction NiO∕ZnO light emitting diodes have been fabricated using low temperature solution-based growth methods. While negligible light emission has been obtained for the as-grown NiO film, devices with annealed NiO film exhibit room-temperature electroluminescence (EL), which was attributed to the detrimental effects of nickel oxide hydroxide in as-grown NiO layers. The device performance can be further modified by insertion of the organic layers between NiO and ZnO and the EL spectra exhibited dependence on the bias voltage. For higher bias voltages, strong UV-violet emission peak can be obtained in spite of the dominance of defect emission in the photoluminescence spectra.
Optical properties of InN containing metallic indium
Authors: Kang Ting-Ting , Hashimoto Akihiro , Yamamoto Akio
Published: March 2008

We theoretically study the optical properties of the composite made of indium nitride (InN) containing metallic indium clusters, using quasistatic approximation and effective medium approximation. The influences of indium cluster shape and volume concentration on the optical properties of entire sample are systematically discussed. Our results can satisfactorily explain recent experiments on the dielectric function of InN containing indium [M. Losurdo, G. Bruno, T.-H. Kim, S. Choi, and A. Brown, Appl. Phys. Lett. 88, 121928 (2006)].
A frustrated nanomechanical device powered by the lateral Casimir force
Authors: Miri MirFaez , Golestanian Ramin
Published: March 2008

The coupling between corrugated surfaces due to the lateral Casimir force is employed to propose a nanoscale mechanical device composed of two racks and a pinion. The noncontact nature of the interaction allows for the system to be made frustrated by choosing the two racks to move in the same direction and forcing the pinion to choose between two opposite directions. This leads to a rich and sensitive phase behavior, which makes the device potentially useful as a mechanical sensor or amplifier. The device could also be used to make a mechanical clock signal of tunable frequency.
Laser annealed HfxZr1−xO2 high-k dielectric: Impact on morphology, microstructure, and electrical properties
Authors: Triyoso Dina H. , Spencer Greg , Hegde Rama I. , Gregory Rich , Wang Xiang-Dong
Published: March 2008

The impact of microsecond laser annealing at 1325°C on physical and electrical characteristics of HfxZr1−xO2 is compared to films annealed at 1000°C for 5s by a conventional rapid thermal process (RTP). Atomic force microscopy analysis shows that laser annealed HfxZr1−xO2 is smoother and void free, while RTP annealed HfxZr1−xO2 exhibits void formation and is rough. The x-ray diffraction analysis revealed higher degree of tetragonality on laser annealed film, particularly for Hf0.5Zr0.5O2 and ZrO2. Furthermore, laser annealed HfxZr1−xO2 devices have good electrical properties (well behaved CV, low gate leakage, and good mobility) whereas RTP annealed devices are not functional.
Post-fire recovery of eastern bristlebirds (Dasyornis brachypterus) is context-dependent
Authors: Bain D. W. , Baker J. R. , French K. O. , Whelan R. J.
Published: March 2008

In late December 2003, a wildfire in the Jervis Bay region of New South Wales burned through an area that previously supported a large population of the endangered eastern bristlebird (Dasyornis brachypterus). The eastern bristlebird has been described as fire-sensitive, and fire is implicated in the decline of the species. The frequency of occurrence of bristlebirds was investigated in the second week after the fire in a range of sites varying in fire intensity. Bristlebirds were found in burned habitats but were less common in the sites that were more intensely burnt. Bristlebirds had been surveyed along transects in this area two months before this fire and were surveyed again 1, 9 and 13 months after the fire. Compared with prefire numbers, bristlebird numbers decreased in burnt areas after the fire and increased in unburnt areas. This pattern was evident for up to nine months after the fire, after which bristlebird numbers returned towards prefire levels in both burnt and unburnt vegetation. This is in contrast to some previous research on bristlebirds and fire. We suggest that bristlebirds avoided the fire by moving to unburnt areas and returned later when conditions were more suitable. We consider that the apparently slight impact of this fire on bristlebirds was due to the close proximity of unburnt habitat and other refuges. The response of bristlebirds and presumably other birds to fire is likely to be strongly context-dependent, so fire management may be able to be designed so as to be compatible with the conservation of local bristlebird populations.
Regional faunal decline - reptile occurrence in fragmented rural landscapes of south-eastern Australia
Authors: Brown Geoff W. , Bennett Andrew F. , Potts Joanne M.
Published: March 2008

Many species of reptiles are sedentary and depend on ground-layer habitats, suggesting that they may be particularly vulnerable to landscape changes that result in isolation or degradation of native vegetation. We investigated patterns of reptile distribution and abundance in remnant woodland across the Victorian Riverina, south-eastern Australia, a bioregion highly modified (>90%) by clearing for agriculture. Reptiles were intensively surveyed by pitfall trapping and censuses at 60 sites, stratified to sample small (<30 ha) and large (>30 ha) remnants, and linear strips of roadside and streamside vegetation, across the regional environmental gradient. The recorded assemblage of 21 species was characterised by low abundance and patchy distribution of species. Reptiles were not recorded by either survey technique at 22% of sites and at a further 10% only a single individual was detected. More than half (53%) of all records were of two widespread, generalist skink species. Multivariate models showed that the distribution of reptiles is influenced by factors operating at several levels. The environmental gradient exerts a strong influence, with increasing species richness and numbers of individuals from east (moister, higher elevation) to west (drier, lower elevation). Differences existed between types of remnants, with roadside vegetation standing out as important; this probably reflects greater structural heterogeneity of ground and shrub strata than in remnants subject to grazing by stock. Although comparative historical data are lacking, we argue that there has been a region-wide decline in the status of reptiles in the Victorian Riverina involving: (1) overall population decline commensurate with loss of >90% of native vegetation; (2) disproportionate decline of grassy dry woodlands and their fauna (cf. floodplains); and (3) changes to populations and assemblages in surviving remnants due to effects of land-use on reptile habitats. Many species now occur as disjunct populations, vulnerable to changing land-use. The status of reptiles in rural Australia warrants greater attention than has been given to date. Effective conservation of this component of the biota requires better understanding of the population dynamics, habitat use and dispersal capacity of species; and a commitment to landscape restoration coupled with effective ecological monitoring.
The short-term effects of an extensive and high-intensity fire on vertebrates in the tropical savannas of the central Kimberley, northern Australia
Authors: Legge Sarah , Murphy Stephen , Heathcote Joanne , Flaxman Emma , Augusteyn John , Crossman Marnie
Published: March 2008

We report the effects of an extensive (>7000 km2), high-intensity late-dry-season fire in the central Kimberley, Western Australia, on the species richness and abundance of mammals, reptiles and birds. Five weeks after the fire we surveyed 12 sites (six burnt, six unburnt); each pair of sites was closely matched for soil type and vegetation. The species richness and abundance of mammals and reptiles was greater at unburnt sites, especially for mammals (with a 4-fold difference in abundance between burnt and unburnt sites). There was an indication that reptiles immigrated into unburnt patches, but mammals did not. There were also species-specific responses to the fire: Rattus tunneyi and Pseudomys nanus were much more abundant in unburnt sites, whereas Pseudomys delicatulus was caught in equal numbers at burnt and unburnt sites. Diurnal reptiles were more abundant at unburnt sites, but nocturnal reptiles were equally common at burnt and unburnt sites. Avian species richness and overall abundance was similar between burnt and unburnt patches, although a few species showed preferences for one state or the other. The overall high trapping success for mammals (18% across all sites; 28% in unburnt patches) contrasts with the well documented mammal collapse in parts of northern Australia and seems paradoxical given that our study area has experienced the same increase in fire frequency and extent that is often blamed for species collapse. However, our study area has fewer pressures from other sources, including grazing by large herbivores, suggesting that the effects of these pressures, and their interaction with fire, may have been underestimated in previous studies.
Toxicity and persistence of sodium fluoroacetate (1080) in the land crab (Gecarcinus lagostoma) on Ascension Island
Authors: Pain D. J. , White R. , Stevenson J. , Bell M. , Williams K. K. , Fisher P. , Wright G.
Published: March 2008

An eradication program for introduced feral cats, using sodium fluoroacetate (1080) bait, was planned on Ascension Island to help breeding seabird populations to recover. We investigated the likelihood of mortality and the occurrence of residual 1080 in the ‘non-target’ Ascension land crab (Gecarcinus lagostoma) through simulating ‘realistic’ and ‘worst case’ exposure to 1080 bait. Crabs feeding on 1080 baits ingested an estimated maximum of 9–56 mg 1080 (kg bodyweight)–1 and although two of 32 treatment crabs died, this mortality was not attributed to 1080 poisoning but to other, unknown, causes. Our results suggest that G. lagostoma has relatively low susceptibility to acute toxic effects of 1080. Most residual 1080 was eliminated rapidly from crab tissue, with concentrations of 0.006–0.070 mg (kg bodyweight)–1 measured in crab claw/leg tissue 9–11 days after exposure. Concentrations of 0.200 and 0.650 mg (kg bodyweight)–1 were measured in the claw tissue of two crabs that died from other causes on the third day of exposure to 1080, indicating potential for secondary exposure of sensitive scavengers or predators of 1080-exposed crabs. We recommend a moratorium on human consumption of all crabmeat for a withholding period following the eradication program. The withdrawal period should be defined by further research on the longevity of 1080 in crab tissues, and be confirmed by monitoring of residues in crabs after baiting.
Colonisation of native tree and shrub plantings by woodland birds in an agricultural landscape
Authors: Barrett G. W. , Freudenberger D. , Drew A. , Stol J. , Nicholls A. O. , Cawsey E. M.
Published: March 2008

Tree planting has become a cornerstone strategy for natural resource management in agricultural landscapes, yet its contribution as habitat for woodland birds has not been fully investigated. A case study from the Holbrook region in southern New South Wales was used to assess woodland birds in young plantings of native trees and shrubs. Ground-foraging insectivorous woodland birds were under-represented in the plantings, partly due to a lack of native forb diversity (wildflowers) and leaf litter. Of 69 woodland bird species recorded over a three-year period, 48 species (70%) occurred in planted sites, 59 species (86%) occurred in remnant woodland, and 34 species (49%) occurred in adjacent paddock sites. The greater diversity of birds in planted sites relative to paddock sites was mostly due to understorey birds. The proportion of mist-netted birds recaptured was similar in both planted (15%) and remnant woodland (16%) sites, suggesting that individual birds were staying in planted sites. The proportion of woodland birds showing breeding activity (as measured by the presence of a brood patch) was slightly lower in planted sites (24% of all woodland species) than in remnant woodland (29%). Birds such as the superb fairy-wren, red-browed finch and southern whiteface were more likely to occur in planted sites, suggesting that plantings provide unique, transitional-stage habitat within agricultural landscapes. Restoring native forbs, as part of a broader strategy of woodland management, will help to reverse the decline of ground-foraging insectivorous woodland birds in agricultural landscapes.
Stereotypes about English as the language of science
Authors: Guardiano Cristina , Favilla M. Elena , Calaresu Emilia
Published: March 2008

The progressive spread of English as the main language of international scientific communication has been interpreted in many different ways by several scholars. The paper presents a brief review of the scientific debate on such topics, focusing on the main stereotypes which have been created in order to provide explanations for the development of English as the language of science, and on the perception of non-Anglophone scholars on the reasons of the predominance of English in scientific literature and their disadvantages with respect to native speakers.

Frequently used stereotypes on English as the language of science are analyzed and discussed in reference to the motivations asserted by linguists and non-linguists. A double ideological evidence can be registered: (1) arguments essentially consist in a-posteriori justifications, (2) English — far away from representing a free choice for non-native scholars — is perceived as the repository of the linguistic power that is desired and worshipped.

The overview closes with the results of a pilot investigation on the languages of scientific publications, conducted on a sample of Italian scholars belonging to various scientific fields.
Proto-discourse and the emergence of compositionality
Authors: Bowie Jillian
Published: March 2008

Two opposing accounts of early language evolution, the compositional and the holistic, have become the subject of lively debate. It has been argued that an evolving compositional protolanguage would not be useful for communication until it reached a certain level of grammatical complexity. This paper offers a new, discourse-oriented perspective on the debate. It argues that discourse should be viewed, not as a level of language structure ‘beyond the sentence’, but as sequenced communicative behaviour, typically but not uniquely involving language. This provides for continuity from exchanges making use of simple communicative resources such as single words and gestures to those making use of complex grammatical conventions. Supporting evidence comes from child language and from original experiments with adults using constrained language systems. The paper shows that the utility of emerging compositional language is not dependent on some critical level of complexity, and so defends the compositional account.
Citizenship, diversity and national identity
Authors: Crick Bernard
Published: March 2008

This article explores the issues of citizenship, diversity and national identity in the context of the introduction of citizenship education in the UK. It considers the historical context of national identity in the UK and notes that the 'British national identity has historically implied
diversity'. It also analyses the views of British national identity in the speeches of major contemporary politicians including Gordon Brown and the challenge they provide for citizenship education
The co-articulation of national identity and interculturalism in the Irish curriculum: educating for democratic citizenship?
Authors: Bryan Audrey
Published: March 2008

Article 2008 This article considers social and educational policy responses to increasing ethnic diversity in the Republic of Ireland and related concerns about the intensification of racism in Irish society in the 'Celtic Tiger' era. Drawing on approaches which emphasise the extent
to which discourses on 'race' and multiculturalism are woven into a more general concern about the nation, I problematise interculturalism as a policy response to the intensification of racism in Irish society in recent years. Drawing on a corpus of recently published policy documents and
curriculum materials currently being used in Irish secondary schools, I argue that racial inequality is more likely to be reproduced, rather than contested, through national and educational policies and practices which are purported to have egalitarian and anti-racist aims. Implications of
the study are discussed in terms of alternative approaches to educating for democratic citizenship.
Amnesia and the Generic Image
Authors: Zangwill O. L.
Published: March 2008

It is pointed out that the fate of generic images has been studied little, if at all, in amnesias of organic origin. Observations are described in a case of alcoholic Korsakoff psychosis which appear to indicate that generic images are subject to Ribot's Law of Regression. The patient, a spinster of 57, with some talent for drawing, was asked to represent a number of objects, e.g. a woman dressed in the latest fashions, which might reasonably be regarded as, “generic” in nature. These drawings suggested that the patient's generic images were, in some cases at least, appropriate to an earlier period of her personal history. In general, this ante-dating effect was in good correspondence with the scope of the retrograde amnesia. Some implications of these findings for the psychological theory of memory are briefly discussed.
The Effects-of Repeatedly Retesting the Same Group on the Same Intelligence Test: II High Grade Mental Defectives
Authors: Heim A. W. , Wallace J. G.
Published: March 2008

Twelve mentally-defective schoolboys between 14 and 16 years of age took an intelligence test (AH 4) once a week, ten times. They took also Progressive Matrices once, after they had finished the AH 4 testing. Subjects of low intelligence were chosen in order to throw some light on the findings of a previous experiment on repeated retesting, in which the subjects were intelligent adults. The main aims of the schoolboy enquiry were to ascertain how far the flattening of the progress curves observed in the earlier enquiry was due to the artificial “ceiling” imposed and how far the part played by variation within the individuals varies with the level of intelligence of the group.

The mentally-defective subjects showed a gradual improvement in test performance with little sign of flattening towards the end; their individual progress curves were far less smooth than had been those of the more intelligent subjects. Other findings included relatively high proficiency on the diagrammatic part of the test, as opposed to the verbal and numerical, and some transfer of training from AH 4 to Progressive Matrices.
An Experimental Study on the Fitness of Signs to Words
Authors: Hall K. R. L. , Oldfield R. C.
Published: March 2008

This experiment, following Bartlett's Picture-writing, was designed to show: how much agreement there would be in the choice of a sign as the most fitting in connection with a word; whether the reasons given for a choice of sign mould vary greatly, and would be rationalizations rather than a primary ground for so choosing; and whether the chosen signs were more easily recalled than the not-chosen.

Six cards were shown to the subject, 011 each of which was one word and two signs. The signs were not intended to represent any object, although none was arbitrary. The subject had to choose the more appropriate sign and give the reason for his choice. Afterwards he had to reproduce all the signs.

Agreement in choosing one of the signs of each pair was surprisingly high, although the reasons varied considerably. The chosen signs were reproduced more accurately and frequently, the reproductions showing the conventionalizing effect of the reasons given.

Choice of a sign as most fitting seemed to depend upon certain formal structural qualities of a general character. The most fitting sign for a verbal setting seemed to combine a conventional structure with simplicity and regularity of design. Linking these results with those of an experiment of Harrower's, it is considered possible that a method may here be available for exploring forms of mental organization not so far tapped by standard intelligence tests.
The Imaginary Questionnaire
Authors: Whitfield J. W.
Published: March 2008

The experiment was designed to throw some light on the statistical problems in the analysis of questionnaire data. Previous work (unpublished) suggested that a simple choice response was partially determined by previous responses; and also that the nature of the determination was changed with changing length of series. A “null” experiment was devised in the form of a questionnaire without any questions, and the distribution of responses was studied with respect to the problems formulated.

The observations are discussed in three sections.

In the statistical discussion an alternative meaning to overall association or dissociation is advanced. This: relates association or dissociation to human behaviour in the serial response situation, rather than to qualities of the questionnaire. It is further suggested that association between specific, questions should be tested against the association in the whole questionnaire, and an appropriate treatment is indicated.

The observations depart from statistical randomness in certain ways. Answers made up almost entirely of one form of response are given less often than would be expected. Long sequences of the same type of response are relatively infrequent, and sequences of alternation of response are also rare. As the material is “null” it implies that the human concept of randomness differs from the statistical concept.

An attempt is made to define the human concept of randomness. It appears that a series of responses which has a pattern, or for which the subject can postulate a simple “cause” will not be accepted as random by the human subject. This raises problems of a perceptual and cognitive nature. It also has a bearing on the design of questionnaires. or experiments involving serial responses.
On the Relation between Transfer and Difficulty of Initial Task
Authors: Szafran J. , Welford A. T.
Published: March 2008

Subjects were required to throw at a target under three conditions of varying difficulty. Six groups of 14 subjects were used, each group receiving one of the six possible orders of presentation of the three conditions.

Results in terms of mean distance from the “bull” indicated that the three conditions were producing different transfer effects. These could not be adequately explained in terms of stimulus-or response-similarity, and accordingly a tentative hypothesis is put forward in terms of the relative difficulty of the condition presented first, to those presented subsequently. It is suggested that transfer tends to be positive from a relatively difficult initial task to a subsequent task which is easier, while transfer will tend to be negative from a relatively easy initial task to one which is more difficult.

The first of the three conditions presented exerted considerably more powerful transfer effects than the second. Three possibilities as to why this should be so, are outlined.
A New Phenomenon of Apparent Movement and its After-Effect
Authors: Deutsch J. A.
Published: March 2008

It is found that a stationary spiral pattern gives an appearance of movement in a flickering light, and, furthermore, that this apparent rotation gives rise to the same kind of after-effect as a spiral actually rotating. The illusion is obtainable over a wide range of conditions. Detailed results are given in the case of six subjects, but a large number of subjects experienced the illusion. The experimenter has as yet found no one who was not subject to the illusion itself. The after-effects are not universally experienced.
Programme for Experiments on Thinking
Authors: Bartlett F. C.
Published: March 2008

In remembering, items are used in the form in which they are alleged to have been perceived at some time in the past. In thinking, however, evidence is given and the essential character of the process is to move beyond this evidence, but in line with it, to something for which so far, no exact or complete perceptual basis is claimed.

From an experimental point of view the best approach is to consider thinking as a high level skill, and to design experiments in the light of what has been discovered during recent years about the learning, practice and achievements of skill on a psycho-motor level.

When this is done, it turns out that the thinking process can usefully be considered as one in which gaps are filled up in accord with specific evidence provided. The fundamental gap-filling processes are either of interpolation or of extrapolation.

In the present paper the methodology proposed is developed and illustrated in a preliminary manner.
An Unusual Case of After-Imagery following Fixation of an “Imaginary” Visual Pattern
Authors: Weiskrantz L.
Published: March 2008

The case of a healthy normal subject is described in which negative after-images were reported to follow fixation of an “imaginary” pattern. The size of the after-image was measured at various distances and found to agree closely with the size of an after-image induced by fixation of a “real” visual pattern, and to conform roughly with Emmert's Law. No evidence for chromatic after-images was obtained. Two controls were conducted, one indicating that the results could not be attributed to after-images resulting from objective aids used to maintain an “imaginary” pattern of constant size; the other discounting the possibility of the subject's having guessed the correct values. Similar phenomena reported in the early literature are briefly mentioned, and some theoretical implications discussed.
Some Effects of Reward on the Strength of Position Stereotypes in the White Rat
Authors: Knöpeelmacher F.
Published: March 2008

Certain aspects of Maier's hypothesis that rigid behaviour stereotypes elicited in an insoluble problem situation are not explicable in terms of goal-motivated learning were tested thus: Forty-one white rats of Wistar stock were exposed to an insoluble problem in a water discrimination unit. Each of the twenty-four animals who formed position stereotypes was assigned to one of four groups. One of these groups served as a control and received no special treatment. Each of the remaining three experimental groups was given a different number of successively rewarded trials to the side of the stereotype. Finally, all groups were presented with a soluble problem, and the strengths of the stereotypes in each group observed in terms of the breaking of the stereotypes.

It was found that the strength of the stereotype behaviour was directly proportional to the number of rewarded trials. None of the stereotypes was sufficiently rigid to meet Maier's criterion of “fixated” response patterns. More stereotypes were formed by males than females. On the other hand no sex differences appeared in the subsequent behaviour of animals who did form stereotypes.

These results are interpreted as showing that stereotyped responses formed under conditions of the present experiment are not qualitatively different from learned responses.
Discrimination Learning and Transposition Behaviour of Rats in a Water Tank Apparatus
Authors: Hunter Ian M. L.
Published: March 2008

The learning, by albino rats, of a size discrimination in a water-tank apparatus is described. The earliest discriminative behaviour of each of the six successful rats is of the one-look type in which the negative stimulus plays the major role. With further training, four of those subjects develop two-look discrimination in which relational properties of the stimuli are important as shown by the appearance of, first, one-step and, then, two-step transposition. The water-tank and jumping apparatuses are briefly compared. Evidence from studies of rats, monkeys and children is presented for the generalization that, within limits, the effect of practice on discriminative behaviour involving stimulus relata is to strengthen relational responding.