bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogen concentration and bonding in nano‐diamond films of varying grain sizes grown by different chemical vapor deposition methods
Authors: Michaelson Sh. , Ternyak O. , Akhvlediani R. , Williams O. A. , Gruen D. , Hoffman A.
Published: August 2007

Hydrogen in a variety of forms (molecular hydrogen, atomic hydrogen, hydrocarbon radicals) is involved in diamond formation. The present work studies the incorporation of hydrogen and its bonding configuration in diamond films composed of diamond grains of varying size which were deposited by three different methods: hot filament (HF), micro wave (MW) and direct current glow discharge (dc GD) chemical vapor deposition (CVD). The size of diamond grains which constitute the films varies in the following way: hundreds of nm in the case of HF CVD (∼300 nm), tens nm in the case of MW CVD (3–30 nm) and a few nm in the case of dc GD CVD (∼5 nm). Raman spectroscopy, secondary ion mass spectroscopy (SIMS) and high resolution electron energy loss spectroscopy (HR‐EELS) were applied to investigate the hydrogen trapping in the films. The retention of hydrogen in the films increases with decreasing grain size, indicating that most likely hydrogen is bonded and trapped in grain boundaries as well as on the films surfaces. Raman and HR‐EELS analysis show that hydrogen is bonded to sp2‐ and sp3‐hybridized carbon, giving rise to typical C–H vibration modes. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modelling the effect of doping metallic carbon nanotubes on their ability to transfer‐dope diamond
Authors: Sque Stephen J. , Ewels Christopher P. , Jones Robert , Briddon Patrick R.
Published: August 2007

Previous theoretical work indicates that carbon nanotubes (CNTs) may, like C60 and C60Fx, act as transfer dopants for diamond; that is, they are capable of extracting electrons from a hydrogen‐terminated diamond substrate, effectively doping the near‐surface region of the diamond p‐type. In the present study, the effect of functionalising/doping the CNTs on their electron‐extraction efficiency has been investigated, using ab‐initio density‐functional theory. Pristine, fluorine‐doped, and potassium‐doped (8,8) CNTs have been modelled both in isolation and lying prone on the (001)–(2 × 1):H surface of diamond. The total energies of the relaxed systems suggest that the CNTs are positively bound to the diamond substrate, while the structures and charge densities indicate that only physisorption has occurred. The electronic band structures are indicative of an enhanced electron transfer following fluorination of the CNT, while potassium doping of the CNT has destroyed the transfer‐doping effect. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multi‐impurity complexes for n‐type diamond: a computational study
Authors: Eyre R. J. , Goss J. P. , Briddon P. R. , Wardle M. G.
Published: August 2007

Doping of diamond using multi‐component, multi‐species structures has been modelled using density functional methods. We find that few combinations of impurities yield donor levels shallower than phosphorus. Complexes involving impurities from the second or lower rows of the periodic table are unbound, and those involving the soluble element nitrogen can often be arranged in passive or even compensating geometries. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Transfer doping of diamond via 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ)
Authors: Goss J. P. , Eyre R. J. , Briddon P. R.
Published: August 2007

Hydrogen terminated diamonds exposed to atmosphere typically exhibit surface p‐type conduction, thought to be due to transfer doping with holes in the surface valence band and negatively charged counter‐ions in an adsorbed layer. The effect has been demonstrated with atmospheric contamination forming an aqueous layer, and by C60 molecules. In this paper we show using first‐principles computational methods that organic layers made up from DDQ molecules may also be a candidate for inducing holes in the diamond surface. The effect appears independent of surface orientation and surface coverage. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microscopic diagnostics of DNA molecules on mono‐crystalline diamond
Authors: Rezek Bohuslav , Shin Dongchan , Uetsuka Hiroshi , Nebel Christoph E.
Published: August 2007

Detailed data about deoxyribonucleic acid (DNA) attachment, arrangement, density and functionality on mono‐crystalline diamond surfaces are obtained by direct measurements in electrolytic solutions using fluorescence microscopy and atomic force microscopy in various regimes (oscillating, contact, phase, and surface potential imaging) and by fitting the data into a microscopic geometrical model of DNA. DNA is immobilized on undoped and boron‐doped diamonds with hydrogen and oxygen surface terminations which were functionalized by aminodecene and nitrofenyl linker molecules. The data show that, except photochemically processed oxidized diamond surfaces, the DNA molecules are covalently linked to diamond in a 65–92 Å thin and highly dense layers (6 × 1012 molecules/cm2) with sub‐nanometer intermolecular spacing and a strong tilt of 31° with respect to the surface. Ordering of these DNA layers shows only a weak (<10%) response to a change of buffer salinity in the range of 1–300 mM. The data are discussed with view to biosensor applications. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling of plasmonic nanostructures: Green's function integral equation methods
Authors: Søndergaard T.
Published: August 2007

Three Green's function integral equation methods are considered for modeling of plasmonic nanostructures, namely the Green's tensor volume integral equation method (VIEM), the Green's tensor area integral equation method (AIEM), and the Green's function surface integral equation method (SIEM). Modeling of plasmonic nanostructures is challenging because of the large contrast between the involved materials, namely metals and dielectrics, sharp corners and edges with associated electric field singularities, and possibly plasmonic resonances. It was found that a standard discretization scheme based on cubic volume elements (VIEM) for a cylindrical gold scatterer or square area elements (AIEM) for a silver cylinder did not work, which is related to the stair‐cased description of the curved surfaces. In the case of the VIEM an alternative approach is studied based on ring volume elements and softening of sharp edges by using a gradual transition of the dielectric constant rather than having sharp interfaces. In the case of the AIEM special surface matching area elements are shown to drastically improve convergence. In the SIEM it is demonstrated that rounding of corners can be crucial for obtaining convergence in the case of a plasmonic resonance. The three methods are exemplified for a range of plasmonic nanostructures, namely the surface plasmon polariton bandgap structure with a bent waveguide channel, the long‐range surface plasmon polariton grating, and a metal nano‐strip resonator for short‐range surface plasmon polaritons. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
HfO2/AlGaN/GaN structures with HfO2 deposited at ultra low pressure using an e‐beam
Authors: Tokranov V. , Rumyantsev S. L. , Shur M. S. , Gaska R. , Oktyabrsky S. , Jain R. , Pala N.
Published: August 2007

We show that HfO2/AlGaN/GaN structures with HfO2 layer deposited using an e‐beam in ultra high vacuum are suitable for field effect transistors. The dielectric constant of the HfO2 was found εHfO > 23–24, which is close to the highest re‐ ported values for this material. The leakage current did not exceed 10–4 A/cm2 at the threshold voltage. The comparison of the losses in the samples with and without HfO2 indicates low concentration of the interface traps. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Erratum: Human sapoviruses: genetic diversity, recombination, and classification
Authors: Hansman Grant S. , Oka Tomoichiro , Katayama Kazuhiko , Takeda Naokazu
Published: August 2007

Reviews in Medical Virology 2007; 17: 133–141

DOI: 10.1002/rmv.533

It has come to our attention that there was an error contained in the above article within Figure 1 on page 134.

In the figure the strain called Cruise ship is classified as GII/3, it should have been classified as GII/5.

We apologise for this anomaly
Studying the separability relation between finite state machines
Authors: Spitsyna Natalia , El‐Fakih Khaled , Yevtushenko Nina
Published: August 2007

Several authors have studied the relationships between non‐deterministic finite state machines (FSMs). These relationships can be used, for example, for deriving conformance tests from specifications represented by FSMs. In this paper, the separability relation between FSMs is studied. In particular, an algorithm is presented that derives a shortest separating sequence of two non‐deterministic FSMs. Given FSMs S with n states and T with m states, it is shown that the upper bound on the length of a shortest separating sequence is 2mn−1. Moreover, the upper bound is shown to be reachable. However, according to the conducted experiments, on average, the length of a shortest separating sequence of FSMs S and T states is less than mn and the existence of a separating sequence significantly depends on the number of non‐deterministic transitions in these FSMs. The proposed algorithm can also be used for deriving a separating sequence of two different states of a single FSM or for deriving a separating sequence of three or more FSMs. Copyright © 2007 John Wiley & Sons, Ltd.
On stochastic learning in predictive wireless ARQ
Authors: Kumar K. S. , Chandramouli R. , Subbalakshmi K. P.
Published: August 2007

Traditional automatic repeat request (ARQ) protocols are channel unaware. That is, they react to channel errors by simply retransmitting erroneous packets and do not proactively decide whether or not to transmit a packet in a given slot based on past channel conditions. Clearly, ARQ protocols operating in this mode are not energy efficient. For example, continuously retransmitting erroneous packets when the wireless channel is in deep fade would cause significant wastage of transmission energy.

In this paper, we present a stochastic learning automaton‐based wireless channel state aware ARQ protocol. The learning automaton learns to predict and track the time‐varying wireless channel conditions based on past observations. A Markov chain model for the channel state transitions is used. No a priori knowledge about the state transition probabilities is required by this predictor. Stochastic convergence of the learning algorithm is proved. The proposed ARQ protocol utilizes the predictions to compute transmission/retransmission policies in an online fashion. No pilot (training) symbols are used by the protocol for channel state prediction thereby avoiding any energy wastage due to the transmission of these symbols. Simulation results show that depending on the channel memory significant energy savings can be attained when compared with standard ARQ protocols. We also discuss the transmission energy versus delay trade‐off. Copyright © 2007 John Wiley & Sons, Ltd.
An adaptive approach for image encryption and secure transmission over multirate wireless sensor networks
Authors: Wang Wei , Peng Dongming , Wang Honggang , Sharif Hamid
Published: August 2007

In this paper, we propose an innovative adaptive secure image delivery approach, to achieve effective and efficient image encryption based on an optimal transmission rate in terms of energy efficiency in wireless sensor networks (WSN). Our contribution is three folds—First, the proposed component based selective encryption scheme achieves high image security, while incurring little encryption overhead; furthermore, the proposed adaptive encryption scheme achieve the best security effort within delay bound; finally, the proposed transmission rate optimization improves energy efficiency, and feeds back effective path capacity parameters for adaptive encryption. Simulation results show a significant gain in both energy efficiency and security based on the proposed approach for image secure transmissions in WSN. Copyright © 2007 John Wiley & Sons, Ltd.
Reconstruction of a Recurrent First Dorsal Web Space Defect Using Acellular Dermis
Authors: Kim John Y. S. , Buck Donald W. , Kloeters Oliver , Eo SuRak , Jones Neil F.
Published: August 2007

Oncologic defects of the hand can be problematic for the reconstructive surgeon. These defects may require a delay in definitive coverage until clear margins of resection can be obtained, which can result in a prolonged period of painful dressing changes and increased risk of soft-tissue infection. In addition, reconstructive options for oncologic defects are often limited to skin grafting, which can yield functional deficits secondary to contracted healing. Currently, there is no definitive method for preventing skin graft contracture; however, acellular dermis has been proposed as a biomechanical scaffold to enhance subsequent skin graft healing and slow this functionally debilitating process. Here, we present a patient with recurrent melanoma of the first dorsal web space. After re-resection of the melanoma, the 11 cm × 5 cm defect was reconstructed using acellular dermis as temporary coverage to allow ample time for permanent section results. Ten days later, after confirming negative margins of resection, a split-thickness skin graft (STSG) was applied over the vascularized neo-dermis. Follow-up clinical examination and the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaires were used to assess outcome. At 7 months, the patient had no recurrence of melanoma and a DASH functional reduction of only 6.9%. After approximately 18 months, the patient's wounds had healed with excellent cosmetic and functional results, without any evidence of a web space contracture. These observations suggest that acellular dermis is a useful adjunct for wound coverage of the hand, particularly in areas of functional importance, such as the first dorsal web space.
Comparing vaginal tape and transobturator tape for the treatment of mild and moderate stress incontinence
Authors: Zhu Lan , Lang Jinghe , Hai Ning , Wong Felix
Published: August 2007

Objective: To compare the efficacy and safety of the tension‐free vaginal tape (TVT) and transobturator suburethral tape (TVT‐O) procedures for the treatment of mild and moderate stress urinary incontinence (SUI). Methods: A total of 56 women were randomly selected to undergo the TVT‐O or the TVT procedure. In some patients, vaginal repair or vaginal hysterectomy was done simultaneously for associated indications. Results: Mean blood loss and hospital stay duration were the same for the 2 groups, but mean ± SD operative time was significantly shorter in the TVT‐O than in the TVT group (16 ± 4 min vs 27 ± 6 min; P < 0.001). On the second day following surgery a residual urine volume less than 100 mL was noted in 86% and 89% of the patients in the TVT‐O and TVT groups, respectively; cure was achieved in 92.9% and 92.6% of the patients. No serious complications occurred in either group. Outcome was subjectively assessed, with the patients followed‐up for a mean of 27.6 months. Conclusion: No significant differences in rates of cure, postoperative urine retention, or operative complications were found following the TVT‐O or the TVT procedure.
Last Interglacial (Eemian) hydrographic conditions in the southwestern Baltic Sea based on dinoflagellate cysts from Ristinge Klint, Denmark
Authors: HEAD MARTIN J.
Published: August 2007

A dinoflagellate cyst record with strong Mediterranean/Lusitanian affinities is described from marine deposits of Eemian age (Last Interglacial; Late Pleistocene) at Ristinge Klint, Denmark, revealing new information about the hydrographic evolution of the southwestern Baltic Sea. A revised correlation of the pollen record at Ristinge Klint with that of the annually laminated site at Bispingen in northern Germany provides temporal control. Approximately the first quarter of Eemian time is represented. A marine ingression into a lake took place during theQuercusrise, about 300 years into the interglacial, and is marked by low (<c. 3 psu) salinities at the base of the Cyprina Clay that increased progressively. An abrupt and significant rise in the inflow of warm, saline waters from the North Sea occurred at about 750 years into the interglacial (theCorylusrise), and at about 1900 years into the interglacial, strongly stratified waters developed. Higher in the Cyprina Clay and continuing to its top, at nearly 3000 years into the interglacial, more open-marine waters are indicated, although fully marine conditions were not reached. The dinoflagellate record throughout the Cyprina Clay at Ristinge Klint is therefore one of increasing marine influence. Summer sea-surface temperatures approached, and may have exceeded, 26–28 °C during early Eemian time, indicating temperatures at least 5 °C warmer than at present. These warm conditions persisted to the top of the record at Ristinge Klint. No evidence exists at Ristinge Klint for the influence of Arctic watermasses, and the paucity of cold-water species throughout the section reflects mild winter temperatures in the southwestern Baltic Sea.

The new speciesSpiniferites ristingensisis formally described, and the nameOperculodinium centrocarpumvar.cezarede Vernal, Goyette & Rodrigues, 1989 is validated.
Elemental and Sr–Nd–Pb isotopic geochemistry of Mesozoic mafic intrusions in southern Fujian Province, SE China: implications for lithospheric mantle evolution
Authors: ZHAO JUN-HONG , HU RUIZHONG , ZHOU MEI-FU , LIU SHEN
Published: August 2007

Cretaceous mafic dykes in Fujian province, SE China provide an opportunity to examine the nature of their mantle source and the secular evolution of the Mesozoic lithospheric mantle beneath SE China. The mafic rocks have SiO2ranging from 47.42 to 55.40 wt %, Al2O3from 14.0 wt % to 20.4 wt %, CaO from 4.09 to 11.7 wt % and total alkaline (K2O+Na2O) from 2.15 wt % to 6.59 wt %. Two types are recognized based on their REE and primitive mantle-normalized trace element patterns. Type-A is the dominant Mesozoic mafic rock type in SE China and is characterized by enrichment of light rare earth elements (LREE) ((La/Yb)n = 2.85–19.0) and arc-like trace element geochemistry. Type-P has relatively flat REE patterns ((La/Yb)n = 1.68–3.43) and primitive mantle-like trace element patterns except for enrichment of Rb, Ba and Pb. Type-A samples show EMII signatures on the Sr-Nd isotopic diagram, whereas type-P rocks have high initial143Nd/144Nd ratios (0.5126–0.5128) relative to the type-A rocks (143Nd/144Nd = 0.5124–0.5127). The type-A rocks have207Pb/204Pb ranging from 15.47 to 15.67 and206Pb/204Pb from 18.26 to 18.52. All the type-A rocks show a negative correlation between143Nd/144Nd and206Pb/204Pb ratios and a positive relationship between87Sr/86Sr and206Pb/204Pb ratios, indicating mixing of a depleted mantle source and an EMII component. Geochemical modelling shows that the parental magmas were formed by 5–15 % partial melting of a spinel lherzolite, and contaminated by less than 1 % melt derived from subducted sediment. The type-P magmas were derived from a mantle source unmodified by subduction components. The wide distribution of type-A dykes in SE China suggests that subduction-modified lithospheric mantle was extensive beneath the Cathaysia Block. Geochemical differences between Mesozoic and Cenozoic mafic rocks indicate that lithospheric thinning beneath SE China occurred in two episodes: firstly by heterogeneous modification by subducted components in early Mesozoic times, and later by chemical–mechanical erosion related to convective upwelling of the asthenosphere during Cenozoic times.
Collapse of the neutral current sheet and reconnection at micro-scales
Authors: SHAIKHISLAMOV I. F.
Published: August 2007

Reconnection physics at micro-scales is investigated in an electron magnetohydrodynamics frame. A new process of collapse of the neutral current sheet is demonstrated by means of analytical and numerical solutions. It shows how at scales smaller than ion inertia length a compression of the sheet triggers an explosive evolution of current perturbation. Collapse results in the formation of a intense sub-sheet and then an X-point structure embedded into the equilibrium sheet. Hall currents associated with this structure support high reconnection rates. Nonlinear static solution at scales of the electron skin reveals that electron inertia and small viscosity provide an efficient mechanism of field lines breaking. The reconnection rate does not depend on the actual value of viscosity, while the maximum current is found to be restricted even for space plasmas with extremely rare collisions. The results obtained are verified by a two-fluid large-scale numerical simulation.
Side-conditioned axisymmetric equilibria with incompressible flows
Authors: THROUMOULOPOULOS G. N. , TASSO H. , POULIPOULIS G.
Published: August 2007

Axisymmetric equilibria with incompressible flows of arbitrary direction are studied in the framework of magnetohydrodynamics under a variety of physically relevant side conditions consisting, for example, in that the plasma temperature or the magnetic field modulus are uniform on magnetic surfaces. To this end a set of pertinent nonlinear ordinary differential equations (ODEs) are transformed to quasilinear ODEs and the respective initial value problem is solved numerically with appropriately determined initial values near the magnetic axis. Several equilibrium configurations are then constructed surface by surface. It turns out that in addition to the usual configurations with a magnetic axis, the non-field aligned flow results to novel toroidal shell equilibria in which the plasma is confined within a couple of magnetic surfaces. In addition, the flow affects the elongation and triangularity of the magnetic surfaces and opens up the possibility of changing the magnetic field topology by creating double toroidal shell-like configurations.
The Wong Lineage Land: Property and Belonging in the New Territories of Hong Kong in 1904
Authors: AIJMER GÖRAN
Published: August 2007

This essay explores the distribution of the ownership of land in a coastal village in the New Territories of Hong Kong at the beginning of the last century. The study examines land and houses as indices of relative wealth in a poor community. Above all, it points to the discursive social use of land as a genealogical tract in an area where written genealogies would have been scarce or nonexisting. Belonging in terms of agnatic continuity and its ramifications over time were mapped out in the agricultural landscape to form a complete depicting graph.
Re-Orientalism: The Perpetration and Development of Orientalism by Orientals
Authors: LAU LISA
Published: August 2007

This article discusses the perpetration of Orientalism in the arena of contemporary South Asian literature in English: no longer an Orientalism propagated by Occidentals, but ironically enough, by Orientals, albeit by diasporic Orientals. This process, which is here termed as Re-Orientalism, dominates and, to a significant extent, distorts the representation of the Orient, seizing voice and platform, and once again consigning the Oriental within the Orient to a position of ‘The Other’. The article begins by analysing and establishing the dominant positionality of diasporic South Asian women writers relative to their non-diasporic counterparts in the genre, particularly within the last half decade. It then identifies three problems with the techniques employed by some diasporic authors which have exacerbated the detrimental effects of Re-Orientalism; the pre-occupation with producing writing which is recognisably within the South Asian genre, the problem of generalisation and totalisation, and the insidious nature of ‘truth claims’.
LMS robotic hand grasp and manipulation planning (an isomorphic exoskeleton approach)
Authors: Chaigneau D. , Arsicault M. , Gazeau J.-P. , Zeghloul S.
Published: August 2007

In order to widen the potentialities of manipulation of the Laboratoire de Mécanique des solides (LMS) mechanical hand, we developed a new planning approach based on the use of a specific exoskeleton. This one has kinematics architecture and dimensions identical to the mechanical hand. This feature allows us to obtain manipulation trajectories for the mechanical hand, very easily and very quickly, by using the exoskeleton, without complex calibration. Manipulation's trajectories are replayed offline with an autonomous control, and, consequently, the exoskeleton is not used with any feedback strategy for telemanipulation. This paper presents the characteristics of this exoskeleton and the graphic interface that we developed. This one uses a method to determine the object's evolution during the manipulation with the exoskeleton, without using exteroceptive sensors. This new approach was tested for standard trajectories by simulation on a Computer-aided design (CAD) robotics system and by using the mechanical hand. Thus, we validate the use concept of an isomorphic exoskeleton to mechanical hand for manipulation planning with the LMS mechanical hand.
Weak asymptotic solution of phase-field system in the case of confluence of free boundaries in the Stefan problem with underheating
Authors: DANILOV V. G.
Published: August 2007

We assume that the Stefan problem with underheating has a classical solution until the moment of contact of two distinct free boundaries and the free boundaries have continuous velocities until the moment of contact. Under these assumptions, we construct a smooth approximation of the global solution of the Stefan problem with underheating, which, until the contact, gives the classical solution mentioned above and, after the contact, gives a solution that is the solution of the heat equation.
A review of technology choice for teaching language skills and areas in the CALL literature
Authors: STOCKWELL GLENN
Published: August 2007

The use of technology in language teaching and learning has been the focus of a number of recent research review studies, including developments in technology and CALL research (Zhao, 2003), CALL as an academic discipline (Debski, 2003), ICT effectiveness (Felix, 2005), and subject characteristics in CALL research (Hubbard, 2005), to name a few. Such studies have contributed to clarifying how language learning technologies have been investigated, but questions remain regarding how these technologies have been used in achieving learning objectives. In other words, what technologies do CALL practitioners select for the teaching of a certain language skill or area such as listening, grammar or pronunciation? Are the decisions to use these technologies made on pedagogical grounds, or alternatively, are there other aspects that are more instrumental in influencing what is used in the language classroom? The purpose of this study is to review the literature to examine what technologies are used in the teaching of the language skills and areas. All empirical research articles appearing in four major English-language journals in the field of CALL (CALICO Journal, CALL, Language Learning & Technology, and ReCALL) from 2001 to 2005 were examined and the results collated to determine (1) what types of technologies are being used in the teaching of specific language skills and areas, (2) whether researchers had a clear idea in mind regarding their choice of technology or technologies in relation to their learning objectives, and (3) whether the researchers attempted to capitalise upon the features inherent in the technology or technologies as opposed to traditional, non-CALL means. The paper concludes with a discussion of the relationship between technology and pedagogical goals.
A road to understanding: A qualitative study into why learners drop out of a blended language learning (BLL) environment
Authors: STRACKE ELKE
Published: August 2007

This paper addresses the views of students of blended language learning (BLL) – a particular learning and teaching environment, that combines face-to-face (f2f) and computer-assisted language learning (CALL). In this instance, the ‘blend’ consisted of learners’ independent self-study phases at a computer, with a CD-ROM, and traditional f2f classroom learning. This paper explores this BLL environment from the participants’ perspective and focuses on three learners who left the class. The aim of the study was to understand the reasons behind those students’ decision to leave, so that ideas might be developed for the successful implementation of BLL environments in the future that would appeal to all learners. The analysis showed that students left the class for three reasons: a perceived lack of support and connection/complementarity between the f2f and computer-assisted components of the ‘blend’; a perceived lack of usage of the paper medium for reading and writing; and the rejection of the computer as a medium of language learning. The paper concludes by pointing out implications for the possible future of BLL.
Integrating CALL into the classroom: the role of podcasting in an ESL listening strategies course
Authors: O’BRIEN ANNE , HEGELHEIMER VOLKER
Published: August 2007

Despite the increase of teacher preparation programs that emphasize the importance of training teachers to select and develop appropriate computer-assisted language learning (CALL) materials, integration of CALL into classroom settings is still frequently relegated to the use of selected CALL activities to supplement instruction or to provide additional practice. For the most part, we are still quite a way from what Bax (2003) calls the normalization stage of CALL, i.e., the stage where CALL becomes invisible and truly integrated. Podcasting, a new method of delivering on-demand audio and video files via the Web, shows promise as a technology that may allow teachers to expand the confines of their classrooms, and is becoming increasingly popular in educational contexts. Current use of podcasting in education remains, however, limited primarily to the delivery of recorded lectures in a portable, online format. We believe podcasting has the potential to not only act as a rich source of input and instruction for students in the language classroom, but also to transform instruction. Consequently, this paper describes a structured attempt to integrate CALL activities in the form of podcasts into an academic English as a Second Language (ESL) course on listening strategies. Preliminary evaluation of this ongoing project suggests that both the teacher and the students find the podcasts to be a positive component of the course.
Malaysian ESL teachers’ use of ICT in their classrooms: expectations and realities
Authors: MD YUNUS MELOR
Published: August 2007

English as a Second Language (ESL) teachers in Malaysia, as in many other countries, are anxious to exploit the potential of Information and Communication Technologies (ICT) to enhance the teaching and learning process. Given the increasing pressure exerted by technological developments on language education, it is important to understand the underlying factors behind teachers’ decisions regarding ICT. Egbert et al. (2002) state that few investigations have been conducted on computer-using language teachers’ development. According to BECTA (1999) the learning potential of ICT is not being realised, because many teachers are not familiar with ICT and do not use it in their teaching. This study investigates the present use of ICT among ESL technical school teachers in teaching, factors that affect the use of ICT and perceptions of their skills in ICT. The theory that frames this study is drawn from theories of learning. The model adopted is Davis’ Technology Acceptance Model (TAM) (1989) which provides a basis for determining ICT attitudes and factors affecting the usage of ICT in teaching. Data was collected via a questionnaire survey of ESL technical school teachers in Malaysia, and followed by semi-structured interviews with them. The questionnaire data was analysed using descriptive statistics and later triangulated with the interviews. The findings will be presented and elaborated upon in this paper.
Critical success factors in a TRIDEM exchange
Authors: HAUCK MIRJAM
Published: August 2007

Computer-mediated-communication (CMC) tools allowing learners to be in contact with native speakers of their target language in other locations are becoming increasingly flexible, often combining different modes of communication in a single web- and internet-based environment. The literature on telecollaborative exchanges reveals, however, that online intercultural communication between language learners “often fails to achieve the intended pedagogical goals” (O’Dowd & Ritter, 2006:624) and warns that “exposure and awareness of difference seem to reinforce, rather than bridge, feelings of difference” (Kern, 2000:256). Yet, research into the reasons for lack of success in CMC-based partnership-learning has, so far, only been carried out on a relatively small scale (see, for example, Thorne, 2005, Ware, 2005, O’Dowd & Ritter, 2006). In autumn 2005, students of French at Carnegie Mellon University (CMU), USA and adult learners of French at the Open University (OU), UK were joined by native French speakers studying for an MA in distance education at the Université de Franche Comté (UFC), France in a pilot Tridem project in which all participants worked on the completion of a series of collaborative tasks. The Tridem partners met over several weeks in an internet-mediated, audio-graphic conferencing environment. The project output, a shared reflection in French and English on cultural similarities and differences, took the form of several collaborative blogs. The paper draws on data from pre- and post-questionnaires, from the work published by the learners in the blogs and from post-treatment, semi-structured interviews with volunteer participants. Beyond considering some of the known factors influencing success and failure in CMC-based collaborations such as discrepancies in target language competence among learners, this article also explores affective issues and difficulties arising from varying levels of multimodal communicative competence. The insights gained are mapped against O’Dowd and Ritter’s (2006) ‘inventory of pitfalls’ in telecollaboration. The result is a tentative framework which allows those involved in setting up and running telecollaborative exchanges to gauge both degree and nature of some of the risks they are likely to encounter.
Constructing a ‘third space’ for EFL learners: Where language and cultures meet
Authors: LIAW MEEI-LING
Published: August 2007

Efforts have been made by language educators and researchers to use computer technology to assist L2 learners’ growth in either linguistic or intercultural competence. Nonetheless, web-based environments devoted to developing both types of competences in tandem are new and experimental. The purpose of this project, which involves the collaboration of EFL educators and computer engineers in Taiwan, is to establish an innovative web-based environment to support students in tertiary levels to develop both types of competences. This web-based EFL learning environment experiments with a few main features: (1) instead of reading articles about a foreign culture, the users of this website read articles about their native culture; (2) two on-line computer-based support tools, a bilingual concordancer and a dictionary, are made available to provide students with contextual supports for language learning; and (3) discussion boards are provided for intercultural communication. The web-based learning environment contains several instructional units. While working on a unit, students read an article and then answer comprehension and vocabulary questions. After reading, students share their responses to the articles with intercultural conversation partners via online forums. To evaluate the effectiveness of the learning environment, the researcher recruited a group of Taiwanese university students to test-use the system. Frequencies of the uses of the two e-referencing tools were calculated. The students’ responses to a questionnaire were examined and informal interviews with the students were conducted. Finally, the students’ forum entries were analyzed. The findings revealed initial interest in using e-referencing tools but a dramatic decrease in use after the first few units had been completed. The students used the concordancer as a link to extensive reading materials and suggested adding pronunciation tools to the dictionary. Questionnaire findings showed that students were generally satisfied with the design of the web-based learning environment. An analysis of the students’ forum entries revealed increases in the length and complexity of sentences in their writings, as well as reductions in grammatical errors, as more units were completed. As for intercultural learning, the content analysis of the forum entries demonstrated different types of intercultural competences. Based on the findings, some implications for revision of the virtual environment to enable more effective learning of English as a foreign language and greater development of intercultural competence are drawn.
Three seedling emergence methods in soil seed bank studies: implications for interpretation of propagule deposition in riparian zones
Authors: Gurnell Angela , Goodson Joanne , Thompson Ken , Mountford Owen , Clifford Nick
Published: August 2007

Samples of soil and recently deposited sediments were collected from the river bed, bank face and bank tops of two lengths (reaches) of the River Frome, Dorset, UK and one reach of the River Tern, Shropshire, UK. Soil propagule bank samples were collected in May 2003, and depositional samples were collected subsequently over four consecutive 4-month periods between June 2003 and October 2004. The samples were subjected to three emergence trials under drained, waterlogged and submerged conditions. Significantly more seedlings germinated in the drained than waterlogged trial, and waterlogged than submerged trials. Drained, waterlogged and submerged trials identified 186, 76 and 37 species, respectively. Six species identified in the waterlogged trials were not identified in the drained trials, and five species in the submerged trials were not found in the drained trials. Submerged trials added two species to the drained and waterlogged results. Application of detrended correspondence analysis (DCA) to average species abundance data, for the sampled hydrological habitats (bed, bank face, bank top) within the soil propagule bank and four depositional data sets, generated different results for the three trials. The drained treatment revealed significant differences between sites, seasons and hydrological habitats, whereas the waterlogged and submerged treatments presented an increasingly homogeneous view of the samples. Our results confirm other propagule bank emergence comparisons and extend them to depositional samples, demonstrating that the strong environmental sieves imposed by waterlogging and submergence restrict emergence of numerous terrestrial, wetland and even some aquatic species that were successfully identified using the drained conditions.
Natural weed seed burial: effect of soil texture, rain and seed characteristics
Authors: Benvenuti Stefano
Published: August 2007

Trials were carried out to investigate natural weed seed burial in a no-till agricultural system. With this aim, 30 important weed species were selected to explore if, and to what extent, seed vertical movement is conditioned by soil texture, cumulative rainfall or by seed characteristics. Without soil tillage, the vertical position of the seeds was only a few millimetres below the surface, but it was dependent on soil texture. Seed burial was much slower (and to lesser depths) in clay soils than in sandy soils. Seeds reached greater depths after 1 year in sandy soil (10% >6 mm) than in clay soils (2% >6 mm). Burial dynamics were also influenced by rainfall and seed weight. The amount of rain necessary to halve weed seeds observable on the soil surface was a function of the soil texture and seed weight; linear regressions between total rainfall amounts and seed weight showed that the slope of the relationship increased as the sand component of the soil decreased (21.1, 35.4 and 39.4 in sandy, loam and silty-clay soil, respectively). A polynomial regression, carried out in sandy soil, between 1000-seed weight and their burial capacity showed an inverse relation (P>0.05) between these two parameters. Seed shape and coat microsculpture also influenced movement, but only minimally.
The effects of hybridization on the small-scale variation in seed-bank composition of a rare plant species,Erica ciliarisL.
Authors: Rose R.J.
Published: August 2007

The size and composition of the seed bank of a rare species (Erica ciliarisL.) was analysed.E. ciliarishybridizes with a common relative in southern England (Erica tetralix). The seed banks of these co-occurring species were measured at a number of sites with a range of vegetation types and different management histories. Additional sets of samples were taken from forestry plantations on former heathland sites, where these species were known to occur. Relatively few hybrid seedlings were found in any of the seed-bank samples, even though their vegetative abundance within the sampling areas was equal to that of the pure plants. However, the abundance in the vegetation of the two pure species was reflected in the seed-bank size on each of the vegetation types, both with and without burning management. The seed banks from the forestry plantations show that the numbers of seeds of bothE. tetralixand the hybrid were depleted, but that the seed bank ofE. ciliariswas not significantly different from that of open heathland seed banks. The long-lived nature of the seed bank indicates that there are opportunities for habitat restoration on former heathland sites.
Endogenous abscisic acid and precocious germination of developing soybean seeds
Authors: Gosparini Carlos O. , Busilacchi Hector A. , Vernieri Paolo , Morandi Eligio N.
Published: August 2007

The germination of developing seeds is very uncommon and is generally associated with deficiencies in abscisic acid (ABA) synthesis or sensitivity. This paper examines the quantitative relationship between the inhibition of precocious germination and endogenous ABA in the embryonic axis (ABAa) of hydrated soybean [Glycine max (L.) Merr.] seeds, isolated after the completion of histodifferentiation and before the beginning of dehydration, as well as the magnitude and evolution of axis sensitivity to endogenous ABA during that period. Developing seeds harvested at 25, 30, 35, 40 and 45 d after anthesis (DAA) were subjected to incubation or washing to induce changes in ABA content. ABA content was measured by radioimmunoassay, using a monoclonal antibody against free ABA. Germinability was measured as the time to 50% germination (t50). Washing and incubation induced eight- and twofold increases, respectively, in the rate of ABAa decline compared with the in planta ABAa decline. The threshold ABAa for inhibition of precocious germination (ABAc) increased slightly from 25 to 40 DAA [1.15–1.66 μg ABA (g DW)− 1]. This contrasted with the substantial decline in ABAa [10.90–2.07 μg ABA (g DW)− 1] during the same period, and indicated that sensitivity to endogenous ABA of hydrated seeds was initially high and diminished slowly during development. The relationship between (ABAa–ABAc) and t50 was linear for immature seeds incubated before and after washing. Below the ABAc, there were no differences in the t50 of 25–45 DAA seeds. The ABAa contribution to the control of precocious soybean seed germination was evident, although other potentially interacting factors were also present.
The potential of the smoke-derived compound 3-methyl-2H-furo[2,3-c]pyran-2-one as a priming agent for tomato seeds
Authors: Jain Neeru , Van Staden Johannes
Published: August 2007

The stimulatory role of 3-methyl-2H-furo[2,3-c]pyran-2-one, a smoke-derived butenolide, on germination and post-germination events is well documented. Previous studies have involved germinating seeds in the continuous presence of the compound. However, commercial growers cannot exploit the potential of the butenolide for large-scale production of crops due to limited availability and environmental constraints. The present study was undertaken to assess the potential of the butenolide as a priming agent of tomato (Solanum esculentumMill.) seeds. Flow cytometry data revealed that butenolide-primed seeds had a higher percentage of nuclei at the 4C stage than water-primed seeds. Emergence of the radicle was much faster in the primed seeds. After 36 h of imbibition, a higher percentage of the butenolide-primed seeds (22%) exhibited radicle emergence compared to the water-primed seeds (12%). While butenolide-primed seeds initially germinated more rapidly than either water-primed or unprimed seeds in a 48-h period, water-imbibed seeds reached a similar germination level as the butenolide-primed seeds by 60 h of incubation. The butenolide-primed seeds produced significantly (P ≤ 0.05) more vigorous seedlings than water-primed seeds or seeds in the continuous presence of either water or butenolide. A gradual decrease in the seedling vigour index was recorded for both water and butenolide-primed seeds with increased seed storage at room temperature. Nevertheless, the vigour index was significantly greater in the butenolide-primed seeds than the water-primed seeds. Vigour indices were significantly (P ≤ 0.05) higher for the butenolide-primed seeds under various stress conditions (salinity, osmoticum or temperature) compared to control or water-primed seeds. Results of the present study suggest that the butenolide is a good seed-priming agent. Additionally, primed seeds retained the promotive effect for a considerable time. This was also the case for tomato seeds under various simulated field stress conditions.
Equilibrium temperatures of porous spheres and their relevance to astrobiology
Authors: Coulson S.G. , Wickramasinghe N.C.
Published: August 2007

Equilibrium temperatures are calculated for porous, organic spheres at a Solar distance of around 1 AU. It is found that the equilibrium temperature of porous grains is highly sensitive to their composition and radius. For porous organic grains of radius 0.1 μm the temperature ranges from 355 to 386 K as the porosity (vacuum volume fraction) increases from 0 to 0.9; for organic grains of radius 0.1 μm with 10% charring the corresponding range is from 448 to 431 K. Such superheated submicron grains, porous or otherwise, may have only a limited role as transporters of fragile biomolecules. Clumps of biological particles with radii in excess of 5 μm are, however, at low enough temperatures to permit such transport at 1 AU.
Darwin to the double helix: astrobiology in fiction
Authors: Brake Mark , Hook Neil
Published: August 2007

From Darwin to the double helix, the last 150 years have seen revolutionary changes in our understanding of life in the Universe. In this time, works of science fiction have provided a valuable, and often overlooked, reflection of the assumptions and attitudes held by society to such changes. This paper will consider key works of film and fiction as a commentary on emergent features of astrobiology, including the work of Fred Hoyle, Olaf Stapledon's Last and First Men (1930) and Star Maker (1937), and Arthur C. Clarke and Stanley Kubrick's cinematic classic, 2001: A Space Odyssey (1968). These popular culture texts represent a useful and inspiring communication of science. Their critical discourse is the reducible gap between the new worlds uncovered by science and the fantastic strange worlds of the imagination. As such, they exemplify a way in which the culture and science of popular astrobiology can be fused.