bluuebunny/crossref_metadata_2025 huggingface dataset:
Oscillator strengths and line widths of dipole-allowed transitions in N142 between 86.0 and 89.7 nm
Authors: Heays A. N. , Lewis B. R. , Stark G. , Yoshino K. , Smith Peter L. , Huber K. P. , Ito K.
Published: November 2009

Oscillator strengths of 23 electric-dipole-allowed bands of N142 in the 86.0–89.7 nm (111 480–116 280 cm−1) region are reported from synchrotron-based photoabsorption measurements at an instrumental resolution of 6.5×10−4 nm (0.7 cm−1) full width at half maximum. The absorption spectrum comprises transitions to vibrational levels of the cn Π1u (n=3,4), o3 Π1u, and cn+1′ Σ1u+(n=3,4) Rydberg states as well as the b Π1u and b′ Σ1u+ valence states. The J dependences of band f-values derived from the experimental line f-values are reported as polynomials in J(J+1) and are extrapolated to zero nuclear rotation in order to facilitate comparisons with the results of coupled Schrödinger equation calculations. Many bands in this study are characterized by a strong J dependence of the band f-values and display anomalous P-, Q-, and R-branch intensity patterns. Predissociation line widths are reported for six bands. The experimental f-value and line-width patterns inform current efforts to develop comprehensive spectroscopic models for N2 that incorporate rotational effects and predissociation mechanisms, and are critical for the construction of realistic atmospheric radiative-transfer models.
Slow waves on magnetic metamaterials and on chains of plasmonic nanoparticles: Driven solutions in the presence of retardation
Authors: Zhuromskyy O. , Sydoruk O. , Shamonina E. , Solymar L.
Published: November 2009

Slow waves on chains or lattices of resonant elements offer a unique tool for guiding and manipulating the electromagnetic radiation on a subwavelength scale. Applications range from radio waves to optics with two major classes of structures being used: (i) metamaterials made of coupled ring resonators supporting magnetoinductive waves and (ii) plasmonic crystals made of nanoparticles supporting waves of near-field coupling. We derive dispersion equations of both types of slow waves for the case when the interelement coupling is governed by retardation effects, and show how closely they are related. The current distribution is found from Kirchhoff’s equation by inverting the impedance matrix. In contrast to previous treatments power conservation is demonstrated in a form relevant to a finite structure: the input power is shown to be equal to the radiated power plus the powers absorbed in the Ohmic resistance of the elements and the terminal impedance. The relations between frequency and wave number are determined for a 500-element line for two excitations using three different methods. Our approach of retrieval of the dispersion from driven solutions of finite lines is relevant for practical applications and may be used in the design of metamaterials and plasmonic crystals with desired properties.
Distribution of normalized critical current of bent multifilamentary Bi2223 composite tape
Authors: Ochiai S. , Fujimoto M. , Shin J. K. , Okuda H. , Oh S. S. , Ha D. W.
Published: November 2009

The distribution of the normalized critical transport current (critical current normalized with respect to the original value) of Bi2223/Ag/Ag alloy composite tape under bending strain of 0%–0.833% was studied experimentally and analytically. The experimental results were analyzed by a modeling approach based on the relation of the heterogeneous damage evolution to the distribution of the critical current. The main results are summarized as follows. (1) The measured distribution of the critical current values varying with bending strain was described well by the present approach. (2) When all specimens were damaged at high bending strains (0.338%–0.833% in the present work), the distribution of the critical current of the bent-damaged specimens was expressed by the three-parameter Weibull distribution function, the reason for which was revealed. (3) The distribution of the irreversible strain was estimated, with which the influence of the increase in the fraction of damaged specimens on the variation of critical current distribution in the low bending strain range (0%–0.35%) was elucidated.
Manipulating stimulated coherent anti-Stokes Raman spectroscopy signals by broad-band and narrow-band pulses
Authors: Rahav Saar , Roslyak Oleksiy , Mukamel Shaul
Published: November 2009

A transition-amplitude based representation of heterodyne detected coherent anti-Stokes Raman signals is used to separate them into a parametric component that involves no change in the material and dissipative processes associated with various transitions between states. Qualitatively different contributions from the two processes are predicted for the signal generated by an overlapping narrow (picosecond) and broad-band (femtosecond) pulse.
Construction of theoretical hybrid potential energy curves for LiH(XΣ+1)
Authors: Cooper Ian L. , Dickinson Alan S.
Published: November 2009

Various all-electron and valence-electron potential energy curves for LiH(XΣ+1) are compared and assessed. Hybrid potential energy curves are constructed from all-electron potentials at short range and a valence-electron calculation otherwise. This approach provides for the X state of LiH an overall potential curve, which is ionic at equilibrium, and presents an avoided crossing with the excited A state, leading to neutral dissociation products. The classical turning points predicted by these purely theoretical hybrid potentials are compared with those of the experimentally based inverted-perturbation approach (IPA) potentials for both Li7H and Li7D. Predicted vibrational energy-level spacings show reasonable (≲1cm−1) agreement with the corresponding IPA values. Rotation and vibration-rotation transition energies arising from the most accurate hybrid potential are shown to compare very favorably with recent high-resolution spectroscopic data on Li7H and Li7D.
On the diffusion and activation of ion-implanted n-type dopants in germanium
Authors: Simoen Eddy , Vanhellemont Jan
Published: November 2009

Some unresolved issues with respect to diffusion and activation of n-type ion-implanted dopants in germanium and of particular interest for shallow junction formation are pointed out and critically discussed. In particular, the absence of extrinsic diffusion during rapid thermal annealing at electron concentrations in the range of a few times 1019 cm−3 and the occurrence of a saturation dopant activation level of the order of 5×1019 cm−3 have been investigated more closely. It is shown that the former can be understood by considering a diffusivity enhancement factor (n/ni)2, with n the free electron concentration and ni the intrinsic carrier concentration, respectively. The saturation of the dopant activation, on the other hand, is determined by the density of states in a degenerately doped semiconductor. Based on these insights, some guidelines for controlling the excess n-type dopant diffusion and activation in germanium can be derived.
Magnetoresistance in magnetic tunnel junctions with an organic barrier and an MgO spin filter
Authors: Szulczewski Greg , Tokuc Huseyin , Oguz Kaan , Coey J. M. D.
Published: November 2009

Exchange-biased magnetic tunnel junctions with a CoFeB/MgO pinned layer, a Co free layer and an aluminum tris-(8-hydroxyquinoline) spacer layer of thickness ranging from 0–8 nm have been prepared by photolithography. The devices show a room-temperature, zero-bias magnetoresistance of 12.5±0.3%, which is unchanged after the crossover from tunneling to hopping transport at a barrier thickness of about 4 nm. The spin-diffusion length in the hopping regime is much greater than 10 nm. The magnetoresistance in the tunneling regime changes sign at a positive bias of 250 mV, and it is maximum at −100 mV.
Electronic photodissociation spectra and decay pathways of gas-phase IrBr62−
Authors: Marcum Jesse C. , Weber J. Mathias
Published: November 2009

We report photodissociation action spectra for the dianion IrBr62− in the range of 1.08–5.6 eV. The photoproducts observed are IrBr6−, IrBr5−, IrBr4− and Br−. Comparison of the action spectra to the aqueous absorption spectrum of K2IrBr6 leads to the determination of solvatochromic shifts of between 0.02 and 0.16 eV in the visible region and approximately 0.3 eV in the ultraviolet. The fragmentation branching ratios vary greatly as a function of photon energy. This behavior can be attributed to differences in the fragmentation mechanisms as well as differences in the excited states that are accessed at different energies. Absorption in the visible region favors fragmentation into IrBr5− and Br−, whereas a number of fragmentation channels and mechanisms are active in the ultraviolet region. These mechanisms include fragmentation as well as electron detachment and dissociative electron detachment.
Wide dynamic range terahertz detector pixel for active spectroscopic imaging with quantum cascade lasers
Authors: Cibella S. , Ortolani M. , Leoni R. , Torrioli G. , Mahler L. , Xu Ji-Hua , Tredicucci A. , Beere H. E. , Ritchie D. A.
Published: November 2009

A superconducting bolometer with an on-chip lithographic terahertz antenna has been illuminated by two quantum cascade lasers operating at 2.5 and 4.4 THz. The detector displays a 1.2 μs time constant, a noise equivalent power of 20 fW/Hz1/2 and a 60 dB dynamic range. We fabricated a monolithic prototype detector array of five elements. This scalable detector is a suitable candidate for terahertz spectroscopic imaging systems, as it can measure both full illuminator power and strongly attenuated or diffuse reflected signals in subsequent frames.
Quantifying effective slip length over micropatterned hydrophobic surfaces
Authors: Tsai Peichun , Peters Alisia M. , Pirat Christophe , Wessling Matthias , Lammertink Rob G. H. , Lohse Detlef
Published: November 2009

We employ microparticle image velocimetry to investigate laminar microflows in hydrophobic microstructured channels, in particular the slip length. These microchannels consist of longitudinal microgrooves, which can trap air and prompt a shear-free boundary condition and thus slippage enhancement. Our measurements reveal an increase in the slip length when the width of the microgrooves is enlarged. The result of the slip length is smaller than the analytical prediction by Philip [Z. Angew. Math. Phys. 23, 353 (1972)] for an infinitely large and textured channel comprised of alternating shear-free and no-slip boundary conditions. The smaller slip length (as compared with the prediction) can be attributed to the confinement of the microchannel and the bending of the meniscus (liquid-gas interface). Our experimental studies suggest that the curvature of the meniscus plays an important role in microflows over hydrophobic microridges.
On carrier spillover in c- and m-plane InGaN light emitting diodes
Authors: Lee J. , Li X. , Ni X. , Özgür Ü. , Morkoç H. , Paskova T. , Mulholland G. , Evans K. R.
Published: November 2009

The internal quantum efficiency (IQE) and relative external quantum efficiency (EQE) in InGaN light-emitting diodes (LEDs) emitting at 400 nm with and without electron blocking layers (EBLs) on c-plane GaN and m-plane GaN were investigated in order to shed some light on any effect of polarization charge induced field on efficiency killer carrier spillover. Without an EBL the EQE values suffered considerably (by 80%) for both orientations, which is clearly attributable to carrier spillover. Substantial carrier spillover in both polarities, therefore, suggests that the polarization charge is not the major factor in efficiency degradation observed, particularly at high injection levels. Furthermore, the m-plane variety with EBL did not show any discernable efficiency degradation up to a maximum current density of 2250 A cm−2 employed while that on c-plane showed a reduction by ∼40%. In addition, IQE of m-plane LED structure determined from excitation power dependent photoluminescence was ∼80% compared to 50% in c-plane LEDs under resonant and moderate excitation condition. This too is indicative of the superiority of m-plane LED structures, most probably due to relatively larger optical matrix elements for m-plane orientation.
Electronic characteristics of the interfacial states embedded in “buffer-free” GaSb/GaAs (001) heterojunctions
Authors: Jallipalli A. , Nunna K. , Kutty M. N. , Balakrishnan G. , Dawson L. R. , Huffaker D. L.
Published: November 2009

We report a comprehensive study of the electronic properties and compensation of the interfacial states embedded in a majority carrier electron region either on one or both sides of the “buffer-free” GaSb/GaAs (001) heterointerface. An abrupt change observed in the forward-bias current (58 mA) for a small variation in the applied bias (0.05 V) is ascribed to the compensation of the interfacial states due to electron tunneling from GaAs into GaSb. As a result, after the first sweep, the compensated interfacial states exhibit low turn-on voltage (0.35 V) and low reverse-bias currents (30 μA at −5 V). Similar compensation is also obtained via δ-doping or annealing the diodes. The diodes analyzed in this study are useful as the heterointerface is embedded in the majority electron region resembles with that of the n-cladding region of p-i-n structures such as lasers, detectors, and solar cells.
Patterned electrode vertical field effect transistor fabricated using block copolymer nanotemplates
Authors: Ben-Sasson Ariel J. , Avnon Eran , Ploshnik Elina , Globerman Oded , Shenhar Roy , Frey Gitti L. , Tessler Nir
Published: November 2009

We report the design and implementation of a vertical organic field effect transistor which is compatible with standard device fabrication technology and is well described by a self consistent device model. The active semiconductor is a film of C60 molecules, and the device operation is based on the architecture of the nanopatterned source electrode. The relatively high resolution fabrication process and maintaining the low-cost and simplicity associated with organic electronics, necessitates unconventional fabrication techniques such as soft lithography. Block copolymer self-assembled nanotemplates enable the production of conductive, gridlike metal electrode. The devices reported here exhibit On/Off ratio of 104.
Measurement of the electron density in a microwave plasma torch at atmospheric pressure
Authors: Zhang Qing , Zhang Guixin , Wang Liming , Wang Xinxin , Wang Shumin , Chen Yan
Published: November 2009

The electron density in a microwave plasma torch at atmospheric pressure was measured with a Mach–Zehnder interferometer. The electron density is on the order of 1017/cm3, one order higher than that deduced from the Stark broadening of spectral lines, and increases with the increase in the microwave power. The spatial distribution of the electron density was obtained. The highest electron density locates at the symmetrical axis of the plasma torch and decreases radially. It was found that the electron density fluctuates within a range of 0.3 with the time under the same experimental conditions.
Resonant nanometric cross-shaped apertures: Single apertures versus periodic arrays
Authors: Lin L. , Hande L. B. , Roberts A.
Published: November 2009

Here localized surface plasmon (LSP) resonances occurring inside cross-shaped apertures arranged in thin metallic films are investigated. It is shown that these resonances can be controlled by altering the geometry of the apertures, whereas surface plasmon polariton excitation and Wood anomalies arising as a consequence of the periodicity distorts the spectrum produced by isolated LSP resonances. Simulations showing the behavior of single apertures versus periodic arrays of apertures are compared with experimental results for periodic arrays.
Effects of well width and growth temperature on optical and structural characteristics of AlN/GaN superlattices grown by metal-organic chemical vapor deposition
Authors: Bayram C. , Péré-laperne N. , Razeghi M.
Published: November 2009

AlN/GaN superlattices (SLs) employing various well widths (from 1.5 to 7.0 nm) are grown by metal-organic chemical vapor deposition technique at various growth temperatures (TS) (from 900 to 1035 °C). The photoluminescence (PL), x-ray diffraction, and intersubband (ISB) absorption characteristics of these SLs and their dependency on well width and growth temperature are investigated. Superlattices with thinner wells (grown at the same TS) or grown at lower TS (employing the same well width) are shown to demonstrate higher strain effects leading to a higher PL energy and ISB absorption energy. Simulations are employed to explain the experimental observations. ISB absorptions from 1.04 to 2.15 μm are demonstrated via controlling well width and growth temperature.
On the interface state density at In0.53Ga0.47As/oxide interfaces
Authors: Brammertz G. , Lin H.-C. , Caymax M. , Meuris M. , Heyns M. , Passlack M.
Published: November 2009

The authors model the capacitance-voltage (CV) behavior of In0.53Ga0.47As metal-oxide-semiconductor (MOS) structures and compare the results to experimental CV-curves. Due to the very low conduction band density of states, ideal III-V MOS structures should present an asymmetric CV behavior, with lower accumulation capacitance on the conduction band side. The absence of this asymmetric CV shape in experimental CV curves points toward the presence of additional states inside the conduction band at the oxide-semiconductor interface. Comparisons between the model and experimental data allow the determination and approximate quantification of a large acceptorlike interface state density above the conduction band edge energy.
Kernel brown centres in macadamia: a review
Authors: Le Lagadec M. D.
Published: November 2009

The incidence of kernel brown centres in macadamia (Macadamia integrifolia and M. tetraphylla and hybrids) has increased substantially in Australia. Although the defect amounts to only ~1% of all kernels processed in Australia, it costs the macadamia industry over AU$2 million per annum. Little formal research has been conducted, although the defect is mentioned widely in informal grower journals. Possible causal factors are reviewed in this article. Evidence suggests that kernel brown centres may be associated with exposure of enzymes in cell membranes and are also associated with incorrect nut-in-shell drying regimes. There appears to be an interaction among nut-in-shell moisture content, nut drying regime, and the incidence of brown centres. There is some indication that storage of wet nuts in poorly ventilated silos increases the potential for developing kernel brown centres. It is recommended that future research focusses on these issues.
Potential of deficit irrigation to increase marginal irrigation response of perennial ryegrass (Lolium perenne L.) on Tasmanian dairy farms
Authors: Rawnsley R. P. , Cullen B. R. , Turner L. R. , Donaghy D. J. , Freeman M. , Christie K. M.
Published: November 2009

In the cool temperate dairy regions of Tasmania, there is heavy reliance on irrigation to maximise pasture performance by ensuring that plants do not suffer water stress. Consequently, irrigation water has often been applied at a greater amount than plant water requirements, resulting in low efficiencies.
An irrigation experiment was undertaken in north-western Tasmania between October 2007 and April 2008, examining the effect of deficit irrigation treatments on pasture growth and water-use efficiency. A rainfall deficit (potential evapotranspiration minus rainfall) of 20 mm was implemented to schedule irrigation, at which point 20, 16, 12, 8, or 0 mm of irrigation water was applied, referred to as treatments I100%, I80%, I60%, I40%, and I0%, respectively. The trial was a randomised complete block design with 4 replications. There were 21 irrigation events between October and April. The experimental area was grazed by 60 Holstein Friesian heifers at a grazing interval coinciding with emergence of 2.5–3.0 new ryegrass leaves/tiller of the I100% treatment.
Cumulative pasture consumption for the irrigated period was 9.2, 8.9, 7.6, 6.9, and 3.7 t dry matter (DM)/ha for the I100%, I80%, I60%, I40%, and I0% treatments, respectively. The resulting marginal irrigation water-use index (MIWUI; marginal production due to irrigation) was 1.29, 1.54, 1.55, and 1.87 t DM/ML, for the I100%, I80%, I60%, and I40% treatments, respectively. The results of this study were modelled using the biophysical model DairyMod, with strong agreement between observed and modelled data. DairyMod was then used to simulate the MIWUI for 5 differing dairy regions of Tasmania using 40 years of climatic data (1968–2007) under 3 differing nitrogen management strategies by the 5 irrigation treatments. The modelling indicated that a MIWUI greater than 2 t DM/ML can be achieved in all regions. The current study has shown that the opportunity exists for irrigated pastoral systems to better manage an increasingly scarce resource and substantially improve responses to irrigation.
Fruit thinning using NAA shows potential for reducing biennial bearing of 'Barnea' and 'Picual' oil olive trees
Authors: Dag Arnon , Bustan Amnon , Avni Avishai , Lavee Shimon , Riov Joseph
Published: November 2009

Biennial bearing is a major horticultural and economic drawback of olive (Olea europaea L.) cultivation, which particularly affects the olive oil industry under intensive production systems. The number of fruits per tree in an on-year is a primary determinant of the biennial cycle. While fruit thinning using NAA shortly after full bloom is commonly practiced to increase fruit size in table olives, the extent of its influence on biennial bearing is unknown. In the present study, the ability of that common naphthaleneacetic acid (NAA) treatment (100 mg/L, 10 days after full bloom) to alleviate biennial bearing in two oil olive cultivars, Picual and Barnea, was poor, although significant influence on the number of fruit was evident solely in Barnea. Picual seemed less susceptible than Barnea to biennial bearing. Consequently, the effect of a broad range of NAA concentrations (0–320 mg/L, 10 days after full bloom) on various yield parameters was investigated during a biennial cycle of Barnea trees. There was a gradual proportional decline in the on-year number of fruits from ~50 000 to 10 000/tree in response to increasing NAA concentrations. The number of return fruits in the off-year was reciprocal to the on-year fruit load, but remained relatively small, below 15 000/tree. The dynamic relationship between fruit load and fruit size in both on- and off-years was a significant compensation factor in fruit and oil yields. In both cultivars, an on-year fruit load smaller than 20 000/tree is likely to provide consistent yearly oil yields ranging from 10 to 12 kg/tree. The results demonstrate the possibility of using NAA post-bloom spraying to balance biennial bearing in oil olives.
Improving estimates of water-limited yield of wheat by accounting for soil type and within-season rainfall
Authors: Oliver Y. M. , Robertson M. J. , Stone P. J. , Whitbread A.
Published: November 2009

Rainfall is the main driver of potential yield in the dryland cropping environment of Australia. Rainfall-based empirically derived models such as that proposed by French and Schultz (1984) (F&S) can be used to determine an upper limit of water-limited potential yield, but F&S often overestimates actual yield as it does not account for rainfall distribution, runoff, drainage, or stored soil water. More complex models are available to predict potential yield more accurately; however, farmers and advisors favour easy-to-use-methods to estimate potential yield.
To derive a simple yet accurate method for estimating potential yield, several adjustments to F&S were evaluated: (1) accounting for stored soil water at sowing, (2) varying the value of the intercept between yield and growing-season rainfall (GSR), (3) varying the water-use efficiency of the crops (WUE) according to soil type, and (4) adjustments to GSR depending on soil plant-available water capacity (PAWC). The water-limited potential yields predicted from these methods were compared with simulations from the daily time-step simulation model APSIM and observed wheat yields from 146 dryland wheat crops, managed to water-limited potential yield, covering the 1996–2006 seasons in the Mediterranean-type growing environments of Australia.
The original F&S method overestimated actual yields, particularly at high rainfall (GSR > 220 mm) when PAWC was low, and underestimated yields at low rainfall (GSR < 220 mm). Significant improvements to the F&S were achieved with a few simple adjustments. With the addition of a variable intercept (dependent upon GSR), accounting for stored soil water at the start of the season and placing a cap on GSR that is a function of the soil PAWC, the predictive performance (RMSE 624 kg/ha) was similar to that gained with the daily time-step model APSIM (RMSE 419 kg/ha). The improved method gave more realistic estimates of water-limited potential yield, particularly at low and high rainfall and on soils of low PAWC.
Resistance to the root-lesion nematode Pratylenchus thornei in wheat landraces and cultivars from the West Asia and North Africa (WANA) region
Authors: Thompson J. P. , O'Reilly M. M. , Clewett T. G.
Published: November 2009

Resistance to the root-lesion nematode Pratylenchus thornei was sought in wheat from the West Asia and North Africa (WANA) region in the Watkins Collection (148 bread and 139 durum wheat accessions) and the McIntosh Collection (59 bread and 43 durum wheat accessions). It was considered that landraces from this region, encompassing the centres of origin of wheat and where P. thornei also occurs, could be valuable sources of resistance for use in wheat breeding. Resistance was determined by number of P. thornei/kg soil after the growth of the plants in replicated glasshouse experiments. On average, durum accessions produced significantly lower numbers of P. thornei than bread wheat accessions in both the Watkins and McIntosh Collections. Selected accessions with low P. thornei numbers were re-tested and 13 bread wheat and 10 durum accessions were identified with nematode numbers not significantly different from GS50a, a partially resistant bread wheat line used as a reference standard. These resistant accessions, which originated in Iran, Iraq, Syria, Egypt, Sudan, Morocco, and Tunisia, represent a resource of resistance genes in the primary wheat gene pool, which could be used in Australian wheat breeding programs to reduce the economic loss from P. thornei.
Selecting for drought tolerance among Australian green couch grasses (Cynodon spp.)
Authors: Zhou Yi , Lambrides Chris , Kearns Ryan , Ye Changrong , Cao Ninh , Fukai Shu
Published: November 2009

Increasing demand for scarce water resources in Australia has led to the selection of turfgrass genotypes with good drought tolerance. Here we describe the development of methodologies for screening green couch grasses (Cynodon spp.) grown in 40-cm PVC pots placed under rainout shelters. The drought tolerance of up to 8 genotypes including 4 commercial varieties (CT2, Grand Prix, Legend, and Winter Green) and 4 wild Australian ecotypes (1-1, 25-a-1, 40-1, and 81-1) was examined in 3 experiments conducted in 2007–08 and 2008–09. In the first experiment, all genotypes were grown with 2 soil types (clay and sandy soils) and 2 clipping heights (5 and 2 cm). Genotypic variation for survival period (defined as the period from the time water was withheld until 100% leaf firing had occurred) was high for the sandy soil × 2 cm clipping height treatment and, because retrieval of roots was easy, this combination was used in Expts 2 and 3 as the best system for screening drought tolerance. This method gave highly repeatable results across 2 years. Wild ecotype 81-1 had a significantly longer survival period than other genotypes, possibly associated with lower stomatal conductance early after water deficit was imposed, a greater root biomass at depth, and greater osmotic adjustment.
Constructing a Second Language
Authors: Ellis Nick C. , Cadierno Teresa
Published: November 2009

This Special Section brings together researchers who adopt a constructional approach to Second Language Acquisition (SLA) as informed by Cognitive and Corpus Linguistics, approaches which fall under the general umbrella of Usage-based Linguistics. The articles present psycholinguistic and corpus linguistic evidence for L2 constructions and for the inseparability of lexis and grammar. They consider the psycholinguistics of language learning following general cognitive principles of category learning, with schematic constructions emerging from usage. They analyze how learning is driven by the frequency and frequency distribution of exemplars within construction, the salience of their form, the significance of their functional interpretation, the match of their meaning to the construction prototype, and the reliability of their mappings. They explore conceptual transfer and the acquisition of second language meaning. They consider the implications of these phenomena for L2 instruction.
Constructions and their acquisition
Authors: Ellis Nick C. , Ferreira-Junior Fernando
Published: November 2009

This paper presents a psycholinguistic analysis of constructions and their acquisition. It investigates effects upon naturalistic second language acquisition of type/token distributions in the islands comprising the linguistic form of English verb-argument constructions (VACs: VL verb locative, VOL verb object locative, VOO ditransitive) in the ESF corpus (Perdue, 1993).  Goldberg (2006) argued that Zipfian type/token frequency distribution of verbs in natural language might optimize construction learning by providing one very high frequency exemplar that is also prototypical in meaning. Ellis & Ferreira-Junior (2009) confirmed that in the naturalistic L2A of English, VAC verb type/token distribution in the input is Zipfian and learners first acquire the most frequent, prototypical and generic exemplar (e.g. put in VOL, give in VOO, etc.). This paper further illustrates how acquisition is affected by the frequency and frequency distribution of exemplars within each island of the construction (e.g. [Subj V Obj Oblpath/loc]), by their prototypicality, and, using a variety of psychological and corpus linguistic association metrics, by their contingency of form-function mapping.
Constructing a Second Language
Authors: Dąbrowska Ewa
Published: November 2009

All the papers in this special section address issues central to cognitive linguistics research: usage-based models with their focus on frequency; multi-word units and the relationship between lexical and grammatical knowledge; and the nature of lexical meaning, especially construal or “thinking for speaking”. Cognitive Linguistics is thus clearly a useful paradigm for L2 research. The contributors also emphasise that many of the processes operating in L1 acquisition are relevant in L2A as well. In this paper, I discuss the opposite side of the coin: how cognitively-inspired L2 research can inform work on first language learning and theoretical linguistics, focussing in particular on three issues that have been extensively studied in an L2 context but neglected by the other language sciences: transfer of knowledge between constructions, the role of explicit learning, and individual differences in linguistic knowledge.
Epidermal growth factor receptor intron 1 CA dinucleotide repeat polymorphism and survival of advanced gastric cancer patients treated with cetuximab plus modified FOLFOX6
Authors: Han Sae‐Won , Oh Do‐Youn , Im Seock‐Ah , Park Sook Ryun , Lee Keun‐Wook , Song Hong Suk , Lee Nam‐Su , Lee Kyung Hee , Choi In Sil , Lee Moon Hee , Kim Min A , Kim Woo Ho , Bang Yung‐Jue , Kim Tae‐You
Published: November 2009

(Cancer Sci 2010; 101: 793–799)

Cetuximab is a monoclonal antibody targeting epidermal growth factor receptor (EGFR). The present study investigated the association between germline genetic polymorphisms and the treatment outcome of cetuximab plus modified leucovovin, fluorouracil, and oxaliplatin (FOLFOX)6 chemotherapy in advanced gastric cancer (AGC). DNA from peripheral blood mononuclear cells of 38 patients enrolled in a phase II study of cetuximab plus modified FOLFOX6 were analyzed for 16 polymorphisms in eight genes (EGFR, epidermal growth factor, transforming growth factor‐α (TGFA), thymidylate synthase, excision repair cross‐complementation group 1, Xeroderma pigmentosum group D, and fragment c gamma receptors (FCGR)2A and 3A). The EGFR intron 1 CA repeat polymorphism was associated with survival. Twenty‐one patients had low repeats (sum of both alleles ≤37), and 17 patients had high repeats (sum ≥38). Patients with low CA repeats had longer progression‐free survival (adjusted hazard ratio [HR] 0.42 [95% confidence interval [CI] 0.19–0.96], P = 0.040) and overall survival (adjusted HR 0.40 [95% CI 0.16–0.99], P = 0.048) compared with patients with high CA repeats. In addition, the tumor EGFR expression was higher in patients with a lower number of CA repeats. The association between the CA repeat status and survival was not found in a separate cohort of AGC patients (n = 68) treated only with modified FOLFOX6. These results suggest that the EGFR intron 1 CA repeat polymorphism could be a useful, predictive biomarker of cetuximab efficacy in AGC and merits further investigation in randomized studies.
Wnt signaling stabilizes the DIXDC1 protein through decreased ubiquitin‐dependent degradation
Authors: Wang Lei , Li Hua , Chen Qi , Zhu Tengfang , Zhu Hongguang , Zheng Li
Published: November 2009

(Cancer Sci 2010; 101: 700–706)

Wnt signaling plays key roles in development, cell growth, differentiation, polarity formation, neural development, and carcinogenesis. DIX Domain Containing 1 (DIXDC1), a novel component of the Wnt pathway, was recently cloned. DIXDC1 is the human homolog of Ccd1, a positive regulator of the Wnt signaling pathway during zebrafish neural patterning. Little has been known about DIXDC1 gene expression regulation. In the present study, we showed that the DIXDC1 protein was induced upon Wnt‐3a stimulation, whereas the DIXDC1 mRNA level was not significantly increased after Wnt‐3a treatment. Positive DIXDC1 staining was detected in colon cancer cells and was colocalized with β‐catenin staining. However, the DIXDC1 mRNA expression decreased in human colon cancer cells compared to the matched normal colon epithelial cells. Our further investigation showed that the DIXDC1 protein was degraded through the proteasome pathway, and the activation of canonical Wnt signaling decreased the ubiquitin‐dependent degradation of both the ectopic and endogenous DIXDC1 protein. In order to explore the possible mechanism of the ubiquitination of DIXDC1, we found that the phosphorylation of DIXDC1 was inhibited by Wnt‐3a. Collectively, these results indicate that canonical Wnt/β‐catenin pathway activation might upregulate DIXDC1 through a post‐translational mechanism by inhibiting the ubiquitin‐mediated degradation of the DIXDC1 protein.
Interacting effects of predation risk and signal patchiness on activity and communication in house mice
Authors: Hughes Nelika K. , Banks Peter B.
Published: November 2009

1. Social signalling can be risky when signals are open to exploitation by eavesdropping predators. Unlike other signal modalities, olfactory signals cannot be ‘switched off’ in the presence of an eavesdropping predator, leaving receivers of scent signals at an increased risk of predation long after the signaller has moved on. Yet individuals of some olfactorily communicating species appear unwilling to forego the receiving of signals under an increased risk of predation. Foraging theory predicts that predation risk can operate at multiple spatial scales, however, such that prey behaviour should be sensitive to the broader olfactory environment beyond the risks of a single point source of odour.

2. Here, we use the house mouse Mus domesticus to test whether the spatial distribution and overall level of receiving activity varies with the spatial distribution of conspecific scent signals and the risks posed by an eavesdropping predator, the cat Felis catus. We assessed the mice’s responses to these risks using overall visitation, activity and scent marking rates at conspecific scented locations (in clumped, random or regular distributions) and the surrounding matrix (non‐scented) locations with and without a predator cue (cat urine). We then used univariate and bivariate spatial point pattern analyses to assess behavioural responses (activity) to both treatments across a range of spatial scales.

3. Visitation, activity and scent marking rates were not affected by the predator cue or the spatial distribution of scents. But these non‐significant results masked a fine scale anti‐predatory response. Mouse activity was significantly more clustered at small scales when in the presence of the predator cue; this response held across all spatial distribution treatments. Mice were also sensitive to the predation risks of clumped scents, and dispersed their activity at intermediate scales significantly more when exposed to the predator cue, than in the control scent treatment.

4. These results suggest that olfactorily communicating species use scale‐sensitive anti‐predatory behavioural changes to compensate for their increased risks of predation when receiving scent signals. We highlight the importance of examining a variety of scales when investigating predator–prey interactions, and discuss the implications of these findings for behaviourally responsive predators and prey.
The habitual meal and snacking patterns of university students in two countries and their use of vending machines
Authors: Spanos D. , Hankey C. R.
Published: November 2009

Background:  Dietary patterns and food choices in western and northern European countries can differ from those in countries that surround the Mediterranean basin. However, irregular meal patterns and the consumption of high‐energy snacks tend to become common in most countries and their association with the prevalence of obesity has been examined in many studies. The first aim of the present study was to describe the habitual meal and snack intakes, including the use of vending machines, for two groups of first‐year university students in two countries of different cultural backgrounds. The second aim was to explore the relationships between body mass index (BMI) and snacking for these two groups.

Methods:  One hundred and sixty first‐year undergraduate university students from two defined universities in Greece (n = 80) and Scotland (n = 80) volunteered to complete a food frequency questionnaire (FFQ). The FFQ comprised 16 questions assessing their meal and snacking habits. Self‐assessed height and weight data were collected.

Results:  The majority of the 160 students reported a BMI in the healthy range (<25 kg m−2). Overall, 26% of the students reported never consuming breakfast. More Scottish students (74%) used vending machines (P < 0.05). More Scottish students consumed chocolate bars and crisps than Greek students (41% and 34% versus 37.5% and 20%, respectively). Only the choice of chocolate bars from vending machines and the consumption of crisps and low fat yogurts were related to BMI (P < 0.05) for both groups.

Conclusions:  University students living in different countries report similar dietary patterns but differ in their snacking habits. No relationships were found between BMI and snacking. There is a need to carry out research to further our understanding of this relationship.
RuO2 thin films deposited by spin coating on silicon substrates: pH‐dependence of the microstructure and catalytic properties
Authors: NOWAKOWSKI P. , KOPIA A. , VILLAIN S. , FREMY M.‐A. , KUSINSKI J. , GAVARRI J.‐R.
Published: November 2009

RuO2 thin films have been deposited on Si substrates by spin coating with precursor solutions having a pH varying between 1.4 and 4. X‐ray diffraction and transmission electron microscopy analyses are used to determine correlations between the solution pH and the film microstructure. As the pH varies, the RuO2 crystal sizes reach a minimum value then increase; the porosity increases at the substrate/film interface with formation of large cavities. The catalytic activity of these RuO2 layers in the presence of flowing air–methane is analysed by Fourier transform infrared spectroscopy of the conversion of CH4 into CO2. The increasing porosity seems to improve the catalytic conversion rate of methane. Electrical impedance spectroscopy analyses show that the conductivity strongly depends on the thin‐film microstructure and porosity.
An investigation of nitride precipitates in archaeological iron artefacts from Poland
Authors: KĘDZIERSKI Z. , STĘPIŃSKI J. , ZIELIŃSKA‐LIPIEC A.
Published: November 2009

The paper describes the investigations of nitride precipitates in a spearhead and a sword found in the territory of Poland, in cremation graveyards of the Przeworsk Culture, dated to the Roman Period. Three different techniques of the examination of nitride precipitates were employed: optical microscope, scanning electron microscope (scanning electron microscope with energy dispersive X‐ray spectrometer) and transmission electron microscope. Two types of precipitates have been observed, and their plate‐like shape was demonstrated. The large precipitate has been confirmed to be γ′‐Fe4N, whereas the small one has been identified as α″‐Fe16N2. The origin of nitride precipitates in archaeological iron artefacts from Poland is probably a result of the manufacturing process or cremation as part of burial rites. An examination of available iron artefacts indicates that nitride precipitates (have only limited effect on mechanical properties) influence the hardness of metal only to a very limited degree.
Mesenchymal stem cells from CD34− human umbilical cord blood
Authors: Lu X. , Alshemali S. , De Wynter E. A. , Dickinson A. M.
Published: November 2009

Umbilical cord blood (UCB) is well known to be a rich source of stem cells especially for haematopoietic stem cells (HSCs). Recently, mesenchymal stem cells (MSCs) have also been shown to exist in cord blood. Although MSCs have been described by a subset of surface antigens after expansion, little is known about the cell surface phenotype of undifferentiated MSCs. The aim of this study therefore was to clarify whether undifferentiated MSCs are resident among CD34− UCB cells. CD34+ cells were separated from UCB mononuclear cells (MNCs) by magnetic sorting and the CD34− cell fractions were cultured in Dulbecco's modified Eagle's medium (DMEM) with 10% foetal calf serum (FCS) and basic‐fibroblast growth factor. Isolated CD34+ cells were also cultured in the same medium. Adherent fibroblast‐like cells at passage 3–4 were analyzed by fluorescence‐activated cell sorting (FACS) for MSC marker expression , and standard adipogenic, osteogenic and chondrogenic assays were used to investigate their differentiation potentials. After 4–5 weeks in culture, the cells from the CD34− fraction became confluent with flat and fibroblast‐like morphology. These cells were positively stained for the mesenchymal cell markers CD29, CD73 and CD105. In adipogenic differentiation, the cells showed oil red O positive and expressed FABP4, adipsin and proliferation‐activated receptor γ‐2 (PPARγ2 genes) associated with adipogenesis. In osteogenic differentiation, calcium accumulation and osteocalcin were detected. The cells grown in chondrogenic conditions were positively stained for human aggrecan and expressed collagen type II and Sox‐9 genes. In contrast, cells from the CD34+ fraction failed to generate any cells with MSC morphology under the same culture conditions. Our results showed that UCB contained MSCs which are only resident in the CD34− fraction. The MSCs could be induced to differentiate into at least three lineage cell types, adipocytes, osteoblasts and chondrocytes.
Treatment‐focused DNA testing for newly diagnosed breast cancer patients: some implications for clinical practice
Authors: Lobb EA , Barlow‐Stewart K , Suthers G , Hallowell N
Published: November 2009

Lobb EA, Barlow‐Stewart K, Suthers G, Hallowell N. Treatment‐focused DNA testing for newly diagnosed breast cancer patients: some implications for clinical practice

There is accumulating evidence that women with breast cancer due to a familial BRCA1 or BRCA2 mutation benefit from specific surgical and chemotherapeutic treatment strategies. However, the rapid identification of such patients during the acute phase of treatment raises a number of issues. This study investigated Australian opinion leaders' views on the issues arising from such ‘treatment‐focused’ genetic testing. Semi‐structured interviews with 34 opinion leaders working in cancer genetics were undertaken. Interviewees acknowledged the introduction of treatment‐focused DNA testing has the potential to positively transform the management of breast cancer patients, but were concerned that certain ethical and logistical issues have yet to be addressed. These include decision‐making and consent, the familial nature of genetic information, and the management of genetics services within familial cancer clinics in the public hospital system in Australia. Service providers will need to have policies and strategies for managing the increased demand. It will also be necessary to include genetic counseling services within familial cancer clinics in the care pathway for newly diagnosed patients prior to any DNA testing to determine adjuvant treatment; such services may be more cost‐effective than expecting surgeons and medical oncologists to fulfill this role.
A fluorometer‐based method for monitoring oxidation of redox‐sensitive GFP (roGFP) during development and extended dark stress
Authors: Rosenwasser Shilo , Rot Ilona , Meyer Andreas J. , Feldman Lewis , Jiang Keni , Friedman Haya
Published: November 2009

Redox‐sensitive GFP (roGFP) localized to different compartments has been shown to be suitable for determination of redox potentials in plants via imaging. Long‐term measurements bring out the need for analyzing a large number of samples which are averaged over a large population of cells. Because this goal is too tedious to be achieved by confocal imaging, we have examined the possibility of using a fluorometer to monitor changes in roGFP localized to different subcellular compartments during development and dark‐induced senescence. The degree of oxidations determined by a fluorometer for different probes was similar to values obtained by confocal image analysis. Comparison of young and old leaves indicated that in younger cells higher levels of H2O2 were required to achieve full roGFP oxidation, a parameter which is necessary for calculation of the degree of oxidation of the probe and the actual redox potential. Therefore, it is necessary to carefully determine the H2O2 concentration required to achieve full oxidation of the probe. In addition, there is an increase in autofluorescence during development and extended dark stress, which might interfere with the ability to detect changes in oxidation–reduction dependent fluorescence of roGFP. Nevertheless, it was possible to determine the full dynamic range between the oxidized and the reduced forms of the different probes in the various organelles until the third day of darkness and during plant development, thereby enabling further analysis of probe oxidation. Hence, fluorometer measurements of roGFP can be used for extended measurements enabling the processing of multiple samples. It is envisaged that this technology may be applicable to the analysis of redox changes in response to other stresses or to various mutants.