bluuebunny/crossref_metadata_2025 huggingface dataset:
Measuring gain and noise in active long-range surface plasmon-polariton waveguides
Authors: De Leon Israel , Berini Pierre
Published: March 2011

We describe techniques and an experimental setup to measure the gain and noise characteristics of a long-range surface plasmon-polariton amplifier consisting of a symmetric metallic stripe waveguide incorporating optically pumped dye molecules in the solution as the gain medium. The setup is capable of acquiring absolute power measurements at the amplifier's output over a narrow optical bandwidth. This allows independent characterization of the amplifier's gain via measurements of stimulated emission and via measurements of amplified spontaneous emission (ASE) over a narrow optical bandwidth, both obtained during the same experimental run. In addition, the absolute power measurements of ASE quantify directly the amplifier's noise.
Piezoresistive pressure sensors with parallel integration of individual single-walled carbon nanotubes
Authors: Burg Brian R. , Helbling Thomas , Hierold Christofer , Poulikakos Dimos
Published: March 2011

A major obstacle in the realization of commercially viable single-walled carbon nanotube (SWNT) devices, hindering the functionality of this uniquely interesting type of material, is their type and site selective integration. Specifically, SWNT based piezoresistive pressure sensors require the incorporation of individual small bandgap semiconducting (SGS-)SWNTs at the positions of highest membrane strain. In this paper, the purely parallel fabrication of ultrasmall piezoresistive pressure sensors (membrane diameter 100–120 μm) with SGS-SWNTs as active transducer elements is demonstrated, using dielectrophoresis. Good alignment avoids strain components other than from the principal axis and superior strain sensitivity to state-of-the-art silicon based piezoresistive pressure sensors is achieved through the highly selective integration of SGS-SWNTs at high dielectrophoretic deposition frequencies. The long-term stable devices have sensitivities as high as S0 ∼0.25 ΔR R−1 bar−1, at a resolution better than 50 mbar, and a power consumption of less than 40 nW. The scale-up of the introduced robust and reliable fabrication process is straight-forward and provides very promising avenues toward successful realization of functional, commercially viable SWNT sensors.
Compact magnetospectrometer for pulsed magnets based on infrared quantum cascade lasers
Authors: Drachenko O. , Winnerl S. , Schneider H. , Helm M. , Wosnitza J. , Leotin J.
Published: March 2011

In this paper we present a portable quantum cascade laser (QCL) based infrared magnetospectrometer covering the spectral range from 5 to 120 μm. The variation of the excitation wavelength is enabled by an easy change of the QCL plug-in modules, while the use of any other external source is also possible. The performance of the setup is illustrated via cyclotron–resonance studies under pulsed magnetic fields up to 60 T.
First-principles calculations of phase transition, elastic modulus, and superconductivity under pressure for zirconium
Authors: Wang Bao-Tian , Zhang Peng , Liu Han-Yu , Li Wei-Dong , Zhang Ping
Published: March 2011

The elasticity, dynamic properties, and superconductivity of α, ω, and β Zr upon compression are investigated by using first-principles methods. Our calculated elastic constants, elastic moduli, and Debye temperatures of α and ω phases are in excellent agreement with experiments. Electron-phonon coupling constant λ and electronic density of states at the Fermi level N (EF) are found to increase with pressure for these two hexagonal structures. For cubic β phase, the critical pressure for mechanical stability is predicted to be 3.13 GPa and at P = 4 GPa the low elastic modulus (E =31.97 GPa) can be obtained. Besides, the critical pressure for dynamic stability of β phase is achieved by phonon dispersion calculations to be ∼26 GPa. Over this pressure, λ and N (EF) of β phase decrease upon further compression. Our calculations show that the large value of superconducting transition temperature Tc at 30 GPa for β Zr is mainly due to the TA1 soft mode. Under further compression, the soft vibrational mode will gradually fade away.
Fractal study for the fractured surface of Nd-Fe-B permanent magnets
Authors: Zhu Minggang , Li Wei , Fang Yikun , Zhang Wenchen , Zhao Rui , Wang Jingdai , Li Anhua , Feng Haibo , Guo Zhaohui , Zhou Mingge , Li Yanfeng
Published: March 2011

Fractal study was used to the analysis of the fractured surface of commercial N50-type Nd-Fe-B sintered magnets. The strain-stress properties of the specimens indicate that the elastic and plastic deformations occur simultaneously during intergranual cracking. The microfractography of the specimens exhibits typical brittle fracture pattern with some toughness dimples, indicating that plastic deformation has happened in some local areas. A “line-measuring dimension” Dline was selected to discuss the fracture behavior. The calculated Dline is about 1.28 and 1.29 for the specimens with c-axis parallel and perpendicular to the applied force direction, respectively. The line-measuring dimension analysis indicates that the fracture feature may be isotropic for our studied specimens, which is a bit inconsistent with previous report on the fracture characterization of Nd-Fe-B sintered magnets. More comprehensive fractal study is further needed to confirm the fracture behavior in detail in the future.
Band structure of a phononic crystal plate in the form of a staggered-layer structure
Authors: Cheng Y. , Liu X. J. , Wu D. J.
Published: March 2011

This study investigates the propagation of Lamb waves in a phononic crystal plate in the form of a staggered-layer structure. Using the analyses of the band structures and the transmission spectra, a significant modulation to the lower-order Lamb modes is demonstrated due to the staggered arrangement. The modulation leads to remarkable changes in the location and width of the phononic band gaps. We further identify the physical mechanism for the effects of the staggered-layer through the particle displacement fields of the eigenmodes. The symmetric mode converts to the antisymmetric mode and vice versa with the existence of the staggered arrangement. In addition, we find that the phononic band gaps are very sensitive to the degree of stagger, which could be indispensable to practical applications such as band gap tuning.
Infrared absorption of hydrogen-related defects in strontium titanate
Authors: Tarun M. C. , McCluskey M. D.
Published: March 2011

Hydrogen has a significant impact on the structural and electronic properties of metals, insulators, and semiconductors. Despite the prevalence of hydrogen, little is known about its behavior in oxides such as strontium titanate (SrTiO3). In this work, hydrogen-related defects in SrTiO3 were investigated using infrared absorption spectroscopy. Two local vibrational modes (LVMs) are observed at 3355 and 3384 cm−1 after hydrogenation at 800 °C. Isotope substitution experiments revealed that the defect consists of two hydrogen atoms bound to host oxygen atoms. From the temperature dependence of the LVMs, we ascribe the complex to a strontium vacancy passivated by two hydrogen atoms. The thermal stability of the defect was determined through a series of isochronal annealing experiments on the hydrogenated SrTiO3 sample. These measurements provided evidence of “hidden hydrogen,” possibly H2 molecules, in the crystal.
Enhanced surface plasmon polariton propagation length using a buried metal grating
Authors: Jose J. , Segerink F. B. , Korterik J. P. , Gomez-Casado A. , Huskens J. , Herek J. L. , Offerhaus H. L.
Published: March 2011

We report an enhancement in the propagation length of surface plasmon polaritons (SPPs) on a metallic grating when the grating is buried in the substrate. A template-stripping technique has been used to fabricate the buried grating. Near-field measurements on the buried and an exposed grating show that the full width at half maximum of the surface plasmon resonances are reduced to 57% for the prism-coupled SPPs and 77% for the grating-coupled SPPs. The reduction in the full width at half maximum is attributed to a decrease in the in-plane directional scattering of the SPPs on the buried grating. The propagation lengths of the SPPs measured beyond the gratings are close to the theoretical SPP propagation length on an ideal gold surface. The buried grating with a significant reduction in the full width at half maximum of the surface plasmon resonances is theoretically shown to improve the figure of merit of grating-incorporated SPR sensors.
Electron correlation effects in the MAX phase Cr2AlC from first-principles
Authors: Du Y. L. , Sun Z. M. , Hashimoto H. , Barsoum M. W.
Published: March 2011

With the help of first-principles GGA+U calculations, the origin of the deviation between the experimental and theoretical data for Cr2AlC was revealed. The structural, electrical and elastic properties of Cr2AlC were well described by considering the Cr 3d on-site Coulomb energy. The temperature effect on the bulk moduli of Cr2AlC was also studied within the quasiharmonic Debye model. Based on the present work, we propose that the electron correlation effects in Cr-containing MAX phases cannot be ignored.
Infrared synchrotron radiation from bending magnet and edge radiation sources for the study of orientation and conformation in anisotropic materials
Authors: Santoro Gonzalo , Yousef Ibraheem , Jamme Frederic , Dumas Paul , Ellis Gary
Published: March 2011

Over the last decade the use of synchrotron infrared microspectroscopy to spatially discriminate chemical and structural features in many different types of materials has grown considerably and has made significant impact in numerous research areas, in particular, in biological sciences and medicine. Although the brightness advantage of the synchrotron infrared (IR) source is well accepted as the key to high spatial discrimination, little attention has been given to measure the polarization properties of the synchrotron light at the sample stage in IR microscopy. In this work the intrinsic polarization of the IR source and its consequences for the study of anisotropic materials are discussed. The polarization characteristics of predominantly bending magnet radiation and predominantly edge radiation sources were measured at the microscope focus and compared. To illustrate the direct use of the intrinsic polarization of these sources in microscopy, the orientation and conformational details of a drawn polymer sample are considered.
Adsorption of ammonia on multilayer iron phthalocyanine
Authors: Isvoranu Cristina , Knudsen Jan , Ataman Evren , Schulte Karina , Wang Bin , Bocquet Marie-Laure , Andersen Jesper N. , Schnadt Joachim
Published: March 2011

The adsorption of ammonia on multilayers of well-ordered, flat-lying iron phthalocyanine (FePc) molecules on a Au(111) support was investigated by x-ray photoelectron spectroscopy. We find that the electron-donating ammonia molecules coordinate to the metal centers of iron phthlalocyanine. The coordination of ammonia induces changes of the electronic structure of the iron phthalocyanine layer, which, in particular, lead to a modification of the FePc valence electron spin.
Highly-efficient single-cell capture in microfluidic array chips using differential hydrodynamic guiding structures
Authors: Chung Jaehoon , Kim Young-Ji , Yoon Euisik
Published: March 2011

This paper presents a highly efficient single cell capture scheme using hydrodynamic guiding structures in a microwell array. The implemented structure has a capturing efficiency of >80%, and has a capacity to place individual cells into separated microwells, allowing for the time-lapse monitoring on single cell behavior. Feasibility was tested by injecting microbeads (15 μm in diameter) and prostate cancer PC3 cells in an 8×8 microwell array chip and >80% of the microwells were occupied by single ones. Using the chips, the number of cells required for cell assays can be dramatically reduced and this will facilitate overcoming a huddle of assays with scarce supply of cells.
Ultrasensitive string-based temperature sensors
Authors: Larsen T. , Schmid S. , Grönberg L. , Niskanen A. O. , Hassel J. , Dohn S. , Boisen A.
Published: March 2011

Resonant strings are a promising concept for ultra sensitive temperature detection. We present an analytical model for the sensitivity with which we optimize the temperature response of resonant strings by varying geometry and material. The temperature sensitivity of silicon nitride and aluminum microstrings was measured. The relative change in resonant frequency per temperature change of −1.74±0.04%/°C of the aluminum strings is more than one order of magnitude higher than of the silicon nitride strings and of comparable state-of-the-art AuPd strings.
Planar mixed flow and chaos: Lyapunov exponents and the conjugate-pairing rule
Authors: Bernardi Stefano , Frascoli Federico , Searles Debra J. , Todd B. D.
Published: March 2011

In this work we characterize the chaotic properties of atomic fluids subjected to planar mixed flow, which is a linear combination of planar shear and elongational flows, in a constant temperature thermodynamic ensemble. With the use of a recently developed nonequilibrium molecular dynamics algorithm, compatible and reproducible periodic boundary conditions are realized so that Lyapunov spectra analysis can be carried out for the first time. Previous studies on planar shear and elongational flows have shown that Lyapunov spectra organize in different ways, depending on the character of the defining equations of the system. Interestingly, planar mixed flow gives rise to chaotic spectra that, on one hand, contain elements common to those of shear and elongational flows but also show peculiar, unique traits. In particular, the influence of the constituent flows in regards to the conjugate-pairing rule (CPR) is analyzed. CPR is observed in homogeneously thermostated systems whose adiabatic (or unthermostated) equations of motion are symplectic. We show that the component associated with the shear tends to selectively excite some of those degrees, and is responsible for violations in the rule.
Mechanical properties of ultralow-dielectric-constant mesoporous amorphous silica structures: Effects of pore morphology and loading mode
Authors: Gungor M. Rauf , Watkins James J. , Maroudas Dimitrios
Published: March 2011

We report results for the dependence of the mechanical properties of ordered mesoporous silica structures on the pore diameter based on molecular-dynamics simulations. We examine structures with spherical pores arranged in a simple cubic lattice and cylindrical pores arranged in a square lattice subjected to uniaxial tension and compression; for the structures with cylindrical pores, both radial and axial loading is studied with respect to the pore orientation. Our analysis provides a unifying explanation to the observed mechanical response based on the mechanical loading effects on the pore wall thickness.
Photoluminescence characteristics of ZnCdO/ZnO single quantum well grown by pulsed laser deposition
Authors: Yang W. F. , Wong L. M. , Wang S. J. , Sun H. D. , Ge C. H. , Lee Alex Y. S. , Gong H.
Published: March 2011

Optical properties of ZnCdO/ZnO single quantum well (SQW) grown on c-sapphire substrate by pulsed laser deposition were investigated. Temperature dependent photoluminescence (PL) measurement was performed from 10 to 300 K to study the carrier localization effect and peak evolution. The LO-phonon replicas up to third order with Huang–Rhys factor of 0.17 were observed. The SQW exhibited very strong PL from the well layer and extremely weak emission from the ZnO barriers, indicating high quality interfaces and highly efficient relaxation.
Understanding the role played by Fe on the tuning of magnetocaloric effect in Tb5Si2Ge2
Authors: Pereira A. M. , dos Santos A. M. , Magen C. , Sousa J. B. , Algarabel P. A. , Ren Y. , Ritter C. , Morellon L. , Ibarra M. R. , Araújo J. P.
Published: March 2011

In this letter, it is shown that when replacing Ge by Fe in Tb5Si2Ge2 the structural transition still occurs and enhances the magnetocaloric effect (MCE) (up to 66%) with maximum of MCE at a critical Fe amount where the magnetic and structural transitions become fully coupled. It is observed that Fe concentration is able to mimic the effect of external pressure as it induces a complex microstructure, that tunes long range strain fields. This knowledge is crucial for the development of strategies toward materials with improved performance for efficient magnetic refrigeration applications.
Few graphene layers/carbon nanotube composites grown at complementary-metal-oxide-semiconductor compatible temperature
Authors: Jousseaume V. , Cuzzocrea J. , Bernier N. , Renard V. T.
Published: March 2011

We investigate the growth of the recently demonstrated composite material composed of vertically aligned carbon nanotubes capped by few graphene layers. We show that the carbon nanotubes grow epitaxially under the few graphene layers. By using a catalyst and gaseous carbon precursor different from those used originally we establish that such unconventional growth mode is not specific to a precise choice of catalyst–precursor couple. Furthermore, the composite can be grown using catalyst and temperatures compatible with complementary-metal-oxide-semiconductor processing (T<450 °C).
High performance external cavity InAs/InP quantum dot lasers
Authors: Chen P. , Gong Q. , Cao C. F. , Li S. G. , Wang Y. , Liu Q. B. , Yue L. , Zhang Y. G. , Feng S. L. , Ma C. H. , Wang H. L.
Published: March 2011

We report on high performance InAs/InP quantum dot tunable external cavity lasers (ECLs) operating in continuous-wave mode at room temperature. A tuning range of 70 nm has been achieved, covering the wavelengths from 1563 to 1633 nm. The threshold current densities are lower than 1625 A/cm2 in the tuning range. More than 23 mW output power was obtained at lasing wavelength of 1594 nm with an external differential quantum efficiency of 10.3%. An even wider tuning range of 98 nm has been obtained from the ECL based on the QD laser lasing in a longer wavelength.
Observation of the photoinduced anomalous Hall effect in GaN-based heterostructures
Authors: Yin C. M. , Tang N. , Zhang S. , Duan J. X. , Xu F. J. , Song J. , Mei F. H. , Wang X. Q. , Shen B. , Chen Y. H. , Yu J. L. , Ma H.
Published: March 2011

The photocurrent has been measured in Al0.25Ga0.75N/GaN heterostructures at room temperature, and the photoinduced anomalous Hall effect (AHE) was observed. The AHE current changes linearly with the varied longitudinal electric fields. Due to the strong Rashba spin–orbit coupling of the two-dimensional electron gas in Al0.25Ga0.75N/GaN heterostructures, the intrinsic anomalous Hall mechanism is supposed to contribute to the photoinduced AHE. The photoinduced AHE measurement proposed in this study could be used to other spin related measurements at room temperature.
Time dependence of piezoelectric d33 coefficient of cellular ferroelectret polypropylene film
Authors: Wan Yongping , Xie Longtao , Zhang Xiaoqing , Zhong Zheng
Published: March 2011

Due to the inherent viscosity of polymer, piezoelectric response in the thickness direction (d33) of cellular ferroelectret films usually depends on the time of measurement. In this letter, the micromechanical theory of viscoelastic composite was extended to predict the time dependence of the overall piezoelectric d33 coefficient of voided charged polymer foam. Experiments were carried out to find the time spectra of piezoelectric d33 coefficient of voided charged polypropylene film. Theoretical simulation agrees well with experiment data.
The two faces of static correlation
Authors: Hollett Joshua W. , Gill Peter M. W.
Published: March 2011

Restricted Hartree–Fock (RHF) and UHF wavefunctions for beryllium-like ions with nuclear charge 3 ⩽ Z ⩽ 5 are found using a near-complete Slater basis set. The triplet (RHF → UHF) instability and correlation energy are investigated as a function of Z and we find that the instability vanishes for Z > 4.5. We reproduce this surprising behavior using a minimal-basis model and, by comparing with the stretched H2 molecule, conclude that “static” (also known as nondynamical, near-degeneracy, first-order, or strong) correlation comes in two flavors: one that can be captured by UHF and another that cannot. In the former (Type A), there is an “absolute near-degeneracy”; in the latter (Type B), there is a “relative near-degeneracy.” This dichotomy clarifies discussions of static correlation effects.
Enhanced electron-hole plasma stimulated emission in optically pumped gallium nitride nanopillars
Authors: Lo M.-H. , Cheng Y.-J. , Kuo H.-C. , Wang S.-C.
Published: March 2011

An enhanced stimulated emission was observed in optically pumped GaN nanopillars. The nanopillars were fabricated from an epitaxial wafer by patterned pillar etching followed by crystalline regrowth. Under optical excitation, a strong redshifted stimulated emission peak emerged from a broad spontaneous emission background. The emission is attributed to the electron-hole plasma gain at high carrier density. The emission slope efficiency was greatly enhanced by 20 times compared with a GaN substrate under the same pumping condition. The enhancement is attributed to the better photon and gain interaction from the multiple scattering of photons among nanopillars.
Freshwater conservation options for a changing climate in California's Sierra Nevada
Authors: Viers Joshua H. , Rheinheimer David E.
Published: March 2011

Catchments of California’s Sierra Nevada have been managed for hydropower, water supply, recreation and the environment, during which regional freshwater ecosystems have experienced extirpations of anadromous fishes, widespread loss in amphibian abundance and increases in non-native species. California’s Mediterranean-montane climate is expected to warm by 2–6°C over the next century, reducing snowpack, causing earlier runoff and altering flows. Freshwater conservation efforts currently rely on a patchwork of legal and regulatory mechanisms, and have failed to achieve their full potential because of weak and uncoordinated implementation. No scheme adequately addresses freshwater conservation objectives such as representation and persistence, and all ignore anticipated impacts of climate change. We recommend that (1) existing legislation be fully implemented, with explicit anticipation of future conditions, (2) local institutions develop and implement a systematic freshwater conservation plan, focusing on resilience to climate warming, (3) policies be crafted to prioritise catchments to emphasise key regional objectives (e.g. conservation) and (4) regional planning agencies with regulatory authority be formed at the catchment level.
Linking water-resource models to ecosystem-response models to guide water-resource planning - an example from the Murray - Darling Basin, Australia
Authors: Lester Rebecca E. , Webster Ian T. , Fairweather Peter G. , Young William J.
Published: March 2011

Objectively assessing ecological benefits of competing watering strategies is difficult. We present a framework of coupled models to compare scenarios, using the Coorong, the estuary for the Murray–Darling River system in South Australia, as a case study. The framework links outputs from recent modelling of the effects of climate change on water availability across the Murray–Darling Basin to a hydrodynamic model for the Coorong, and then an ecosystem-response model. The approach has significant advantages, including the following: (1) evaluating management actions is straightforward because of relatively tight coupling between impacts on hydrology and ecology; (2) scenarios of 111 years reveal the impacts of realistic climatic and flow variability on Coorong ecology; and (3) ecological impact is represented in the model by a series of ecosystem states, integrating across many organisms, not just iconic species. We applied the approach to four flow scenarios, comparing conditions without development, current water-use levels, and two predicted future climate scenarios. Simulation produced a range of hydrodynamic conditions and consequent distributions of ecosystem states, allowing managers to compare scenarios. This approach could be used with many climates and/or management actions for optimisation of flow delivery to environmental assets.
Threatening processes and conservation management of endemic freshwater fish in the Mediterranean basin: a review
Authors: Hermoso Virgilio , Clavero Miguel
Published: March 2011

Mediterranean endemic freshwater fish are among the most threatened biota in the world. The Mediterranean basin has experienced substantial reductions in precipitation and water availability, which will worsen with climate change. Current water policy is directed to increase water-supply demands, especially for agriculture, and not to improve water-use efficiency and implement integrated and sustainable water management. Illegal extractions are common, exacerbating problems for important protected areas. Management is needed to mitigate the conflicts between environmental water and human demand, and ensure availability of water to maintain ecological processes and Mediterranean freshwater biodiversity. Water availability is not the only threat, although it is exacerbated by pollution and invasive species. The uneven spatial distribution of threats across the Mediterranean basin requires different strategies to conserve freshwater biodiversity. Implementation of multi-national laws (e.g. Water Framework Directive in the European Union) will help future management of freshwater ecosystems. Management actions must be planned at whole-catchment scales, with collaboration among different countries and water-management authorities. The current reserve area is small compared with other areas in the world and driven by terrestrial interests, and should be evaluated for its effectiveness to protect the Mediterranean freshwater biodiversity.
Taking a second look: climate change, periodic relicensing and improved management of dams
Authors: Pittock Jamie , Hartmann Joerg
Published: March 2011

Dams affect rivers and other freshwater ecosystems around the world. The structural performance and service delivery of many dams has seldom been assessed; many are unsafe and no longer deliver designed benefits. Changes in hydrology from climate change will require assessment of safety and operations of infrastructure. This creates an opportunity during relicensing for modification or removal of dams to render them safe, maximise their services and minimise social and environmental impacts. We examined case studies of reassessment of dams from Australia (New South Wales), China, France and the United States that illustrated the following: the management challenge of aging and unsafe dams; unrealised opportunities to improve environmental, social and economic benefits; and the benefits of inventory and relicensing systems. Key elements of an ideal regulatory system to optimise water infrastructure performance are identified, comprising periodic (time-limited) relicensing of all infrastructure overseen by an independent regulatory agency that would take decisions in the public interest through a transparent process, involving public participation. Each dam would have an identified owner who must apply best-available technologies to maximise safety, socioeconomic and environmental performance. Dam renovation could minimise current non-climate impacts, improve migration of aquatic wildlife and even attenuate some climate impacts on freshwater biota.
A Ramsar wetland in crisis - the Coorong, Lower Lakes and Murray Mouth, Australia
Authors: Kingsford Richard T. , Walker Keith F. , Lester Rebecca E. , Young William J. , Fairweather Peter G. , Sammut Jesmond , Geddes Michael C.
Published: March 2011

The state of global freshwater ecosystems is increasingly parlous with water resource development degrading high-conservation wetlands. Rehabilitation is challenging because necessary increases in environmental flows have concomitant social impacts, complicated because many rivers flow between jurisdictions or countries. Australia’s Murray–Darling Basin is a large river basin with such problems encapsulated in the crisis of its Ramsar-listed terminal wetland, the Coorong, Lower Lakes and Murray Mouth. Prolonged drought and upstream diversion of water dropped water levels in the Lakes below sea level (2009–2010), exposing hazardous acid sulfate soils. Salinities increased dramatically (e.g. South Lagoon of Coorong >200 g L–1, cf. modelled natural 80 g L–1), reducing populations of waterbirds, fish, macroinvertebrates and littoral plants. Calcareous masses of estuarine tubeworms (Ficopomatus enigmaticus) killed freshwater turtles (Chelidae) and other fauna. Management primarily focussed on treating symptoms (e.g. acidification), rather than reduced flows, at considerable expense (>AU$2 billion). We modelled a scenario that increased annual flows during low-flow periods from current levels up to one-third of what the natural flow would have been, potentially delivering substantial environmental benefits and avoiding future crises. Realisation of this outcome depends on increasing environmental flows and implementing sophisticated river management during dry periods, both highly contentious options.
Australia's Murray - Darling Basin: freshwater ecosystem conservation options in an era of climate change
Authors: Pittock Jamie , Finlayson C. Max
Published: March 2011

River flows in the Murray–Darling Basin, as in many regions in the world, are vulnerable to climate change, anticipated to exacerbate current, substantial losses of freshwater biodiversity. Additional declines in water quantity and quality will have an adverse impact on existing freshwater ecosystems. We critique current river-management programs, including the proposed 2011 Basin Plan for Australia’s Murray–Darling Basin, focusing primarily on implementing environmental flows. River management programs generally ignore other important conservation and adaptation measures, such as strategically located freshwater-protected areas. Whereas most river-basin restoration techniques help build resilience of freshwater ecosystems to climate change impacts, different measures to enhance resilience and reoperate water infrastructure are also required, depending on the degree of disturbance of particular rivers on a spectrum from free-flowing to highly regulated. A crucial step is the conservation of free-flowing river ecosystems where maintenance of ecological processes enhances their capacity to resist climate change impacts, and where adaptation may be maximised. Systematic alteration of the operation of existing water infrastructure may also counter major climate impacts on regulated rivers.
Support or competition?
Authors: Vallotton Claire D.
Published: March 2011

Dynamic Skills Theory (DST) posits that skills within domains may promote or suppress other skills as they first develop, resulting in spurts of growth in one skill concurrently with regression in another. I test this premise by examining development of two preverbal representational skills: manual pointing and symbolic gestures. Pointing is a robust early communicative gesture, indicating infants’ awareness of others’ attention, but limited in ability to represent infants’ conceptual repertoires as they grow beyond the immediate environment. Symbolic gestures are more specific but less flexible representational tools. Both skills predict language, yet no study has addressed the effects of these skills on each other. I observed the gesturing behavior of 10 infants over 8 months in a gesture-rich environment to test the effects of each skill on the other. Supporting DST, results show early pointing predicted earlier, but not more, symbolic gesturing, while symbolic gesturing did suppress pointing frequency.
From gesture to sign and from gesture to word
Authors: Morgenstern Aliyah , Caët Stéphanie , Collombel-Leroy Marie , Limousin Fanny , Blondel Marion
Published: March 2011

In this paper, we explore the issue of (dis)continuity between gestures and signs and gestures and words by comparing three longitudinal follow-ups of a hearing monolingual French speaking child, a deaf signing child (LSF), and a hearing bilingual (French-LSF) child. Our study indicates that the development of the same manual form (the index finger point) is influenced by the input children receive in the modalities they have at their disposal. Interestingly, the bilingual (French-LSF) child presents an intermediate profile as far as the number of points she uses is concerned. Our analyses do not enable us to differentiate pointing “gestures” from pointing used as a linguistic sign since we could observe no systematic formal distinction. But our study suggests that pointing facilitates the three children’s entry into syntax: pointing gestures or/and signs are more and more combined to words and/or signs, facial expressions, gaze, in complex linguistic productions and with more and more deictic and anaphoric values.
How the hands control attention during early word learning
Authors: Rader Nancy de Villiers , Zukow-Goldring Patricia
Published: March 2011

We have proposed that gestures play a significant role in directing infants’ attention during early word learning when caregivers synchronize the saying of a word with a dynamic gesture; this synchronization functions to bring sight and sound together, providing a basis for perceiving them as belonging together (Zukow-Goldring & Rader, 2001). To test this claim, we presented 9–14 month-old infants with videos of speakers using synchronous dynamic vs. static gestures (Study 1) or synchronous dynamic vs. asynchronous dynamic gestures (Study 2) while introducing a novel object. Eye tracking allowed us to measure where infants looked over time during the word–object pairings and during a test for word learning. We hypothesized that dynamic gestures would draw infants’ attention from the mouth to the object, that infants would attend more to the object at the time the word was spoken when the gesture was dynamic and synchronous with speech, and that synchrony of gesture and speech would result in better word learning. These three hypotheses were supported.
Infant movement as a window into language processing
Authors: Fais Laurel , Leibowich Julia , Hamadani Ladan , Ohira Lana
Published: March 2011

We demonstrate differential, systematic, cross-modal responses to language by contrasting the regularities of infant movement behavior in contexts in which infants are presented with language stimuli, with those exhibited in the context of music. Using a detailed coding system, we show that infants recognize the social underpinnings of language and respond to language stimuli with vocal, gaze, head, and torso, (but not arm or manual) movements that differ from those exhibited to music stimuli. We propose that measures of these sorts of bodily gestures can not only provide a reliable supplement to looking time measures for gauging infant language abilities, but also uncover novel, richly textured nuances to our understanding of infant language acquisition.
Transcribing and annotating multimodality
Authors: Millet Agnès , Estève Isabelle
Published: March 2011

This paper deals with the central question of transcribing deaf children’s productions. We present the annotation grid we created on Elan®, explaining in detail how and why the observation of the narrative productions of 6 to 12 year-old deaf children led us to modify the annotation schemes previously available. Deaf children resort to every resource available in both modalities: voice and gesture. Thus, these productions are fundamentally multimodal and bilingual. In order to describe these specific practices, we propose considering verbal and non-verbal, vocal and gestural, materials as parts of one integrated production. A linguistic-centered transcription is not efficient in describing such bimodal productions, since describing bimodal utterances implies taking into account the ‘communicative desire’ (‘vouloir-dire’) of the children. For this reason, both the question of the transcription unit and the issue of the complexity of semiotic interactions in bimodal utterances need to be reconsidered.
Corpus linguistics and theoretical linguistics
Authors: Barlow Michael
Published: March 2011

This paper examines the relationship between corpus linguistics and theoretical linguistics from a variety of standpoints. We consider the nature of the fit between particular theoretical approaches and the three areas in which corpus linguistics has made a significant contribution to our understanding of language: the provision of frequency information, the highlighting of the importance of collocations, and the description of variation and text types. The complex relationship between data, theory, and representation is described with the aim of situating corpus-based research with respect to different linguistic theories, looking broadly at British and American traditions and paying particular attention to usage-based models of language. We then briefly discuss some current issues surrounding theoretical developments within corpus linguistics, including the divide between cognitive and social perspectives; the representation of corpus-based generalisations; and the relationship between patterns in corpus data and patterns in the mind.
A comparative study of introductory it in research articles across eight disciplines
Authors: Peacock Matthew
Published: March 2011

This paper presents a corpus-based analysis of the form, function, and frequency of introductory it plus that-clause and to-clause complementation. These structures are said to be particularly important in academic English. We examined disciplinary variation in 288 research articles across eight disciplines, four science and four non-science — Biology, Chemistry, Physics, Environmental Science, Business, Language and Linguistics, Law, and Public and Social Administration. We examined all 6,008 occurrences of it, recorded 110 different forms of the patterns, and investigated function. Results indicate that Biology, Chemistry, and Environmental Science writers used the structures significantly less frequently than non-science writers, while Law used them more often. Numerous other statistically significant disciplinary differences were found. Conclusions are that the structure performs the important functions of evaluating the likelihood or validity of propositions, evaluating or commenting on the difficulty of procedures and evaluating or commenting on the necessity of procedures.
When Worlds Elide: Culture, Dialogue and Identity in Multi-Professional Settings
Authors: Holloway Pete , Seebohm Henri
Published: March 2011

Dramatherapists work in a variety of multi-disciplinary contexts, often where other more dominant professional perspectives prevail. This paper considers the cultural politics of such contexts through the ideas of Antonio Gramsci and Raymond Williams. The authors discuss core dramatherapy ideas and more radical theatrical ideas to explore how dramatherapists may maintain and develop their own distinct identity within the multi-professional setting, and make a distinctive contribution to the multi-disciplinary team.
Dramatherapy and Spirituality in Dementia Care
Authors: Jaaniste Joanna
Published: March 2011

Dramatherapy lends itself seamlessly to a person-centred approach, particularly important for elderly people who are nearing the end of their lives. The dramatherapy group affords a holding environment where existential issues and key life questions can be worked with creatively. Although their expression may sometimes seem chaotic (as in dementia), elderly people are often the guardians or holders of much end-of-life wisdom. By means of story, metaphor, play and improvisation, cultural questions and answers can assist with celebration, reminiscence, pleasure and grieving, and ultimately the transition to a dignified and spiritually meaningful death. In this way, the spirituality of the person with dementia can be explored and accepted.

Spirituality has informed theatre and drama throughout history, and the healing properties of the arts are referred to in the histories of many societies. In contemporary western culture, especially that of the last 50 years, there has been a growth of consciousness that creative activity can contribute to people's health and well-being and that the area of spirituality is integral, and perhaps even central, to psycho-social health and a sense of well-being.

In this paper, selected dramatherapy literature is reviewed, that supports the contention that the practice of these therapies is an effective means of assisting elderly people afflicted with moderate-to-severe dementia to value their ageing process. Arts therapies may assist them to cope with the grief and loss their ageing may entail, as they lose friends and physical and mental capacity, in a society where elderly people are marginalised.

Case studies and theoretical examples are presented to show how group work can be structured so that issues of elderly people with dementia can be addressed in a creative way.
Cadherins trade bonds
Authors: Short Ben
Published: March 2011

Study describes how adhesion molecules rearrange their interactions to exit cell junctions.
Pascale Cossart: The ins and outs of Listeria
Authors: Sedwick Caitlin
Published: March 2011

Cossart studies how Listeria monocytogenes manipulates the biology of its host cells.
Cadherin exits the junction by switching its adhesive bond
Authors: Hong Soonjin , Troyanovsky Regina B. , Troyanovsky Sergey M.
Published: March 2011

The plasticity of cell–cell adhesive structures is crucial to all normal and pathological morphogenetic processes. The molecular principles of this plasticity remain unknown. Here we study the roles of two dimerization interfaces, the so-called strand-swap and X dimer interfaces of E-cadherin, in the dynamic remodeling of adherens junctions using photoactivation, calcium switch, and coimmunoprecipitation assays. We show that the targeted inactivation of the X dimer interface blocks the turnover of catenin-uncoupled cadherin mutants in the junctions of A-431 cells. In contrast, the junctions formed by strand-swap dimer interface mutants exhibit high instability. Collectively, our data demonstrate that the strand-swap interaction is a principal cadherin adhesive bond that keeps cells in firm contact. However, to leave the adherens junction, cadherin reconfigures its adhesive bond from the strand swap to the X dimer type. Such a structural transition, controlled by intercellular traction forces or by lateral cadherin alignment, may be the key event regulating adherens junction dynamics.
Assembly and architecture of precursor nodes during fission yeast cytokinesis
Authors: Laporte Damien , Coffman Valerie C. , Lee I-Ju , Wu Jian-Qiu
Published: March 2011

The contractile ring is essential for cytokinesis in most fungal and animal cells. In fission yeast, cytokinesis nodes are precursors of the contractile ring and mark the future cleavage site. However, their assembly and architecture have not been well described. We found that nodes are assembled stoichiometrically in a hierarchical order with two modules linked by the positional marker anillin Mid1. Mid1 first recruits Cdc4 and IQGAP Rng2 to form module I. Rng2 subsequently recruits the myosin-II subunits Myo2 and Rlc1. Mid1 then independently recruits the F-BAR protein Cdc15 to form module II. Mid1, Rng2, Cdc4, and Cdc15 are stable node components that accumulate close to the plasma membrane. Both modules recruit the formin Cdc12 to nucleate actin filaments. Myo2 heads point into the cell interior, where they efficiently capture actin filaments to condense nodes into the contractile ring. Collectively, our work characterizing the assembly and architecture of precursor nodes defines important steps and molecular players for contractile ring assembly.
Dynamics of adherens junctions in epithelial establishment, maintenance, and remodeling
Authors: Baum Buzz , Georgiou Marios
Published: March 2011

The epithelial cadherin (E-cadherin)–catenin complex binds to cytoskeletal components and regulatory and signaling molecules to form a mature adherens junction (AJ). This dynamic structure physically connects neighboring epithelial cells, couples intercellular adhesive contacts to the cytoskeleton, and helps define each cell’s apical–basal axis. Together these activities coordinate the form, polarity, and function of all cells in an epithelium. Several molecules regulate AJ formation and integrity, including Rho family GTPases and Par polarity proteins. However, only recently, with the development of live-cell imaging, has the extent to which E-cadherin is actively turned over at junctions begun to be appreciated. This turnover contributes to junction formation and to the maintenance of epithelial integrity during tissue homeostasis and remodeling.
Casein kinase 1 delta functions at the centrosome to mediate Wnt-3a–dependent neurite outgrowth
Authors: Greer Yoshimi Endo , Rubin Jeffrey S.
Published: March 2011

Previously we determined that Dishevelled-2/3 (Dvl) mediate Wnt-3a–dependent neurite outgrowth in Ewing sarcoma family tumor cells. Here we report that neurite extension was associated with Dvl phosphorylation and that both were inhibited by the casein kinase 1 (CK1) δ/ε inhibitor IC261. Small interfering RNAs targeting either CK1δ or CK1ε decreased Dvl phosphorylation, but only knockdown of CK1δ blocked neurite outgrowth. CK1δ but not CK1ε was detected at the centrosome, an organelle associated with neurite formation. Deletion analysis mapped the centrosomal localization signal (CLS) of CK1δ to its C-terminal domain. A fusion protein containing the CLS and EGFP displaced full-length CK1δ from the centrosome and inhibited Wnt-3a–dependent neurite outgrowth. In contrast to wild-type CK1ε, a chimera comprised of the kinase domain of CK1ε and the CLS of CK1δ localized to the centrosome and rescued Wnt-3a–dependent neurite outgrowth suppressed by CK1δ knockdown. These results provide strong evidence that the centrosomal localization of CK1δ is required for Wnt-3a–dependent neuritogenesis.
Citing data sources in the social sciences: do authors do it?
Authors: MOONEY Hailey
Published: March 2011

It is expected that authors will provide citations for all papers referenced in their writings. The necessity of providing citations for data is not so widely recognized. Proponents of the data‐sharing movement have advocated the citation of datasets in order to recognize contributions and enhance access. This study examines a sample of papers from the Inter‐University Consortium for Political and Social Research (ICPSR) Bibliography of Data‐Related Literature that are based on secondary analysis of datasets available in the ICPSR data archive to determine the data citation practices of authors. The results indicate that many authors fail to cite the data used in secondary analysis studies. Possible reasons for the dismal state of data citation practices are considered, including the recent introduction of data into the scholarly record and its marginalization as an information format. Updating citation practices to include datasets will support data sharing and foster responsible scholarship.
JUSP in time: a partnership approach to developing a journal usage statistics portal
Authors: CRADOCK Chris , MEEHAN Paul , NEEDHAM Paul
Published: March 2011

The Journal Usage Statistics Portal (JUSP) service is expanding rapidly, and aims to encompass all NESLi2‐participating publishers by the end of 2011, together with all UK higher‐education institutions subscribing to deals from those publishers. A key part of the success of JUSP will be the implementation of the Standardized Usage Statistics Harvesting Initiative (SUSHI) protocol for automatic harvesting of usage statistics directly from publishers. This article outlines development of the service and describes how JUSP is working with Oxford University Press to deliver usage statistics to libraries. We also describe future developments at JUSP, including the creation of our own SUSHI server, and explain how new initiatives and enhancements are developed and rolled out in conjunction with our participating institutions.