bluuebunny/crossref_metadata_2025 huggingface dataset:
A Holistic Approach to Supporting the Learning of Young Indigenous Students: One Case Study
Authors: Warren Elizabeth , Quine Janine
Published: October 2013

Due to the high turnover of teaching staff in remote schools, the long-term sustainability of educational initiatives that enhance Indigenous student's learning is a major concern. This article presents a study of a remote Indigenous school (Ischool) situated in Queensland. Ischool has changed its approach to leadership, particularly the distribution of power and authority within the school context, to address this concern. The focus is on building the capacity of Indigenous staff. It is a holistic and communal approach that is culturally inclusive of Indigenous ways of being and operating. The approach actively ensures that power and authority, and roles and responsibilities, are shared between Indigenous and non-Indigenous staff. Data were collected in one-on-one interviews with Indigenous and non-Indigenous participants involved in the change process. A grounded methodological approach was utilised using open coding to break down data into distinct units of meaning. The results reveal that the Indigenous community of Ischool were more committed to promoting and sustaining education initiatives that improve student learning when: (a) school leadership structures were inclusive of Indigenous voices and Indigenous ways of relating; (b) power and authority within the school context was shared, and (c) Indigenous staff were included in professional development opportunities that foster collaborative classroom partnerships and legitimise their own knowledge of their culture and community.
Maîtres Chez Nous: Some Questions about Culture and Continuity
Authors: BOOTH W. JAMES
Published: October 2013

Alan Patten's social lineage account of cultural continuity is the most recent effort to provide multicultural theory with a non-essentialist concept of culture, its continuity and loss that meets broadly liberal normative desiderata. In this essay, I argue that it too fails to offer an alternative to essentialism, to meet standard liberal normative stipulations, and to construct a theory of continuity sufficient to underpin the present claims of involuntarily incorporated communities. That result is theoretically interesting for it shows the deep intractability of the problems at the core of liberal multiculturalism.
Was Weber a Methodological Weberian?
Authors: Runciman W.G.
Published: October 2013

The recent publication of the entirety of Max Weber’s methodological writings in an English translation by Bruun and Whimster offers an opportunity to reassess the question how far he himself consistently adhered to his own precepts about Wertfreiheit and the construction and deployment of ideal types. It is argued that Weber himself saw the problem not as a logical but as a purely psychological one, and that he could therefore justify the apparent contradictions between his precepts and his practice as either deliberate exercises in something other than Wissenschaft or, in his wissenschaftlich writings, as lapses capable in principle of correction. In conclusion, it is briefly suggested that Weber would regard the major advances made in the human behavioural sciences since his lifetime as generally consistent with his own methodology.
Critical Naïveté?
Authors: LeQuire Peter Brickey , Silver Daniel
Published: October 2013

Between 1940 and 1944, sociologist Talcott Parsons and political scientist Eric Voegelin engaged in a vigorous correspondence, discussing the origins of totalitarianism and modern anti-Semitism, the legacy of Max Weber, patterns of secularization set in motion by the Protestant Reformation, the methodology and goals of social science, and more. This article introduces and explicates the surprisingly amicable and intellectually rich exchange between these two seemingly different thinkers. Although the letters hold obvious historical interest, their variegated topics are also closely thematically related, revealing an inner logic that we interpret as a theoretical search for “critical naïveté”. This logic, we argue, is relevant to contemporary discussions about the social, political, and scientific legacies of world-transcendent spiritual traditions.
One-dimensional macro-scale matter wave dynamics potentially embedded in the Lorentz trajectory
Authors: VARMA RAM K.
Published: October 2013

We point the rather unusual existence of a potential embedding in the Lorentz trajectory – charged particle trajectory in a magnetic field – of a one-dimensional matter wave dynamics on the macro-scale as demonstrated through one-dimensional matter wave interference effects on the macro-scale, as well as the observation of a curl-free vector potential in one dimension, also on the macro-scale. Such an embedding is a manifestation of the generation of the quantum modulation of the de Broglie wave of the particle along the magnetic field, arising concomitantly, with a scattering-induced transition across Landau levels in consequence of quantum entanglement between the parallel and perpendicular degrees of freedom.
How to quantify solid–liquid phase transition: Lennard–Jones system case study
Authors: KLUMOV BORIS A.
Published: October 2013

In this paper we analyzed different measures, characterizing the melting of Lennard–Jones solid, and associated with the properties of both the translational and the orientational local order. It has been shown that the most sensitive indicator of melting is the cumulant of the probability distribution function over w6 bond-order parameter. The criterion of melting based on the indicator is proposed; the criterion can be used for any solids, having fcc/hcp types of symmetry.
New insights on the Golgi complex ofTritrichomonas foetus
Authors: De ANDRADE ROSA IVONE , CARUSO MARJOLLY BRIGIDO , RODRIGUES SILAS PESSINI , GERALDO REINALDO BARROS , KIST LUIZA WILGES , BOGO MAURICIO REIS , GONZAGA LUIZ , DE VASCONCELOS ANA TEREZA R , MORGADO-DÍAZ JOSE ANDRES , ZINGALI RUSSOLINA BENEDETA , BENCHIMOL MARLENE
Published: October 2013

Tritrichomonas foetusis a protist that causes bovine trichomoniasis and presents a well-developed Golgi. There are very few studies concerning the Golgi in trichomonads. In this work, monoclonal antibodies were raised against Golgi ofT. foetusand used as a tool on morphologic and biochemical studies of this organelle. Among the antibodies produced, one was named mAb anti-Golgi 20.3, which recognized specifically the Golgi complex by fluorescence and electron microscopy. By immunoblotting this antibody recognized two proteins with 60 and 66 kDa that were identified as putative beta-tubulin and adenosine triphosphatase, respectively. The mAb 20.3 also recognized the Golgi complex of theTrichomonas vaginalis, a human parasite. In addition, the nucleotide coding sequences of these proteins were identified and included in theT. foetusdatabase, and the 3D structure of the proteins was predicted. In conclusion, this study indicated: (1) adenosine triphosphatase is present in the Golgi, (2) ATPase is conserved betweenT. foetusandT. vaginalis, (3) there is new information concerning the nucleic acid sequences and protein structures of adenosine triphosphatase and beta-tubulin fromT. foetusand (4) the mAb anti-Golgi 20.3 is a good Golgi marker and can be used in future studies.
Species or local environment, what determines the infection of rodents by Toxoplasma gondii?
Authors: GOTTELAND CÉCILE , CHAVAL YANNICK , VILLENA ISABELLE , GALAN MAXIME , GEERS RÉGINE , AUBERT DOMINIQUE , POULLE MARIE-LAZARINE , CHARBONNEL NATHALIE , GILOT-FROMONT EMMANUELLE
Published: October 2013

Toxoplasmosis is largely present in rural areas but its spatial distribution in this environment remains poorly known. In particular, it is unclear if areas of high density of cats, the only hosts excreting Toxoplasma gondii, constitute foci of high prevalence. To improve our understanding of the spatial distribution of T. gondii in rural areas, we performed a serological survey in rodents from two villages in France. We trapped 710 rodents including commensal rats and meadow or forest voles and mice. The presence of T. gondii was examined using PCR, mice inoculation and modified agglutination test for antibodies (MAT). We conducted multivariate and discriminant analyses to identify biological, ecological or spatial variables that could explain T. gondii serology in rodents. We then used a logistic regression to assess the relative influence of each explanatory variable. Overall seroprevalence was 4·1%. Commensal-rats were more infected (12·5%) than non-commensal species (3·7%). However, the major determinant of the risk of infection was the distance to the nearest farm (OR = 0·75 for 100 m), which explained the risk in all species or non-commensal species only. We contrast the role of species characteristics and that of the local environment, and discuss the risk of environmental contamination for humans.
Integrating environmental policies towards a network of protected and quiet areas
Authors: VOTSI NEFTA-ELEFTHERIA P. , KALLIMANIS ATHANASIOS S. , MAZARIS ANTONIOS D. , PANTIS JOHN D.
Published: October 2013

Environmental policy integration is an acknowledged principle of sustainable development. Spatial planning may be a useful means of integrating two policies with differing objectives. The Birds and Habitats Directives of the European Union (EU) aim at preserving biodiversity through the conservation of the Natura 2000 protected areas network, while the EU's Environmental Noise Directive aims at improving human health and wellbeing by controlling environmental noise, through the preservation of Quiet Areas (QAs). Using Greece as an example, an integrated network of Natura 2000 sites and QAs permitted the identification of potential spatial overlaps. The established Natura 2000 network incorporates more than 30% of the QAs located in the open countryside of Greece, and the combined network includes 17 out of the 19 conservation priority habitat types. Flagship species (like bear, wolf and wild goat) show a preference for sites containing QAs. It may be possible to combine these two EU policies efficiently, as protected and quiet areas appear to be mutually beneficial.
Church-State Relations in the United Kingdom: A Westminster View
Authors: Cranmer Frank
Published: October 2013

In any discussion of church-state relations in the United Kingdom, it should be remembered that there are four national Churches: the Church of England, the (Reformed) Church of Scotland, the Church in Wales (disestablished in 1920 as a result of the Welsh Church Act 1914) and the Church of Ireland (disestablished by the Irish Church Act 1869). The result is that two Churches are established by law (the Church of England and the Church of Scotland) and enjoy a particular constitutional relationship with the state, while the other Churches and faith-communities (the Roman Catholics, the Free Churches, the Jews, Muslims, Hindus, Sikhs and others) have particular rights and privileges in particular circumstances.
Idris, a general-purpose dependently typed programming language: Design and implementation
Authors: BRADY EDWIN
Published: October 2013

Many components of a dependently typed programming language are by now well understood, for example, the underlying type theory, type checking, unification and evaluation. How to combine these components into a realistic and usable high-level language is, however, folklore, discovered anew by successive language implementors. In this paper, I describe the implementation ofIdris, a new dependently typed functional programming language.Idrisis intended to be ageneral-purposeprogramming language and as such provides high-level concepts such as implicit syntax, type classes anddonotation. I describe the high-level language and the underlying type theory, and present a tactic-based method forelaboratingconcrete high-level syntax with implicit arguments and type classes into a fully explicit type theory. Furthermore, I show how this method facilitates the implementation of new high-level language constructs.
Factors influencing the resilience of carers of individuals with dementia
Authors: Cherry MG , Salmon P , Dickson JM , Powell D , Sikdar S , Ablett J
Published: October 2013

Most individuals with dementia live in the community, receiving care from family or lay carers. Carers’ wellbeing, and the quality of the care they provide, depends on their resilience in the face of the challenges associated with caring for someone with dementia. However, factors associated with carers’ resilience are not yet fully understood. The aim of this review is to present a narrative synthesis of factors, materials and resources associated with carers’ resilience. Electronic and hand searches identified relevant published literature, which was narratively synthesized. A framework consisting of three inter-related domains of factors influencing carers’ resilience emerged, encompassing: social and cultural factors; properties of the care relationship; and carers’ psychological factors. Holistic assessment based on this framework can help practitioners to identify vulnerable carers and to target help on factors that help to make them vulnerable but that are amenable to change.
CAMELLIA OCONORIANA (THEACEAE), A NEW SPECIES FROM VIETNAM
Authors: Orel G. , Wilson P. G. , Curry A. S. , Truong Luu Hong
Published: October 2013

The new species Camellia oconoriana Orel, Curry & Luu (Theaceae), endemic to Lam Dong Province, Vietnam, is described and illustrated. It is compared to Camellia species in sections Archaecamellia, Stereocarpus, Piquetia and Chrysantha. Morphological evidence supports a transitional placement in Camellia sect. Chrysantha ser. Chrysanthae.
Gamete quality of streaked prochilod Prochilodus lineatus (Characiformes) after GnRHa and dopamine antagonist treatment
Authors: Viveiros Ana T.M. , Gonçalves Antônio C.S. , Di Chiacchio Isabela M. , Nascimento Ariane F. , Romagosa Elizabeth , Leal Marcelo C.
Published: October 2013

The efficiency of Ovaprim™ salmon gonadotropin-releasing hormone agonist (GnRHa) and dopamine antagonist on the induction of spawning and spermiation in Prochilodus lineatus in comparison with the commonly used method using pituitary extract (PE) was evaluated. Females received PE at 0.5 + 5.0 mg/kg and Ovaprim™ at 0.05 + 0.45 ml/kg or at 0.125 + 0.375 ml/kg. All males received a first dose of PE at 0.4 mg/kg and then PE at 4.0 mg/kg or Ovaprim™ at 0.25 ml/kg. Oocyte, egg, larvae and sperm quality were evaluated. All females spawned and oocyte, egg and larvae quality were similar between Ovaprim™-treated (both doses) and PE-treated females. Data from females were pooled and the mean values were: 242 g ova weight, 15% ova index, 1209 oocytes/g ova, 284,539 oocytes/female, 183 oocytes/g body weight, 1.18 mm oocyte diameter, 49% fertilization rate, 43% hatching rate and 89% normal larvae. Sperm quality was similar between Ovaprim™-treated and PE-treated males. Data from males were pooled and the mean values of semen were: volume of 3.0 ml, 14.9 × 109 sperm/ml, osmolality of 283 mOsm/kg, pH of 7.4, 71% motile sperm, 217 μm/s curvilinear velocity, 102 μm/s straight-line velocity and 189 μm/s average path velocity. Ovaprim™ treatment can be used for commercial reproduction of P. lineatus, without any loss of gamete quality in comparison with PE treatment.
Language and thought in a multilingual context: The case of isiXhosa
Authors: BYLUND EMANUEL , ATHANASOPOULOS PANOS
Published: October 2013

Situated within the grammatical aspect approach to motion event cognition, this study takes a first step in investigating language and thought in functional multilinguals by studying L1 isiXhosa speakers living in South Africa. IsiXhosa being a non-aspect language, the study investigates how the knowledge and use of additional languages with grammatical aspect influence cognition of endpoint-oriented motion events among L1 isiXhosa speakers. Results from a triads-matching task show that participants who often used aspect languages and had greater exposure to English in primary education were less prone to rely on endpoints when categorising motion events.
The Resettlement of Homeless Young People: Their Experiences and Housing Outcomes
Authors: Crane Maureen , Warnes Anthony M. , Barnes Jennifer , Coward Sarah
Published: October 2013

This article reports the experiences of 109 homeless people aged seventeen to twenty-five years in England who were resettled into independent accommodation during 2007/08. It focuses on housing, finances, employment and access to support services. After fifteen/eighteen months, 69 per cent of the young people were still in their original accommodation, 13 per cent had moved to another tenancy and 18 per cent no longer had a tenancy. Most were glad to have been resettled but found the transition very challenging, particularly with regard to managing finances and finding stable employment. The prevalence of debts increased substantially over time, and those who moved to private-rented accommodation had the poorest outcomes. People who had been in temporary accommodation more than twelve months prior to resettlement were more likely to retain a tenancy, while a history of illegal drug use and recent rough sleeping were associated negatively with tenancy sustainment.
A novel DYRK1B inhibitor AZ191 demonstrates that DYRK1B acts independently of GSK3β to phosphorylate cyclin D1 at Thr286, not Thr288
Authors: Ashford Anne L. , Oxley David , Kettle Jason , Hudson Kevin , Guichard Sylvie , Cook Simon J. , Lochhead Pamela A.
Published: October 2013

DYRK1B (dual-specificity tyrosine phosphorylation-regulated kinase 1B) is amplified in certain cancers and may be an oncogene; however, our knowledge of DYRK1B has been limited by the lack of selective inhibitors. In the present study we describe AZ191, a potent small molecule inhibitor that selectively inhibits DYRK1B in vitro and in cells. CCND1 (cyclin D1), a key regulator of the mammalian G1–S-phase transition, is phosphorylated on Thr286 by GSK3β (glycogen synthase kinase 3β) to promote its degradation. DYRK1B has also been proposed to promote CCND1 turnover, but was reported to phosphorylate Thr288 rather than Thr286. Using in vitro kinase assays, phospho-specific immunoblot analysis and MS in conjunction with AZ191 we now show that DYRK1B phosphorylates CCND1 at Thr286, not Thr288, in vitro and in cells. In HEK (human embryonic kidney)-293 and PANC-1 cells (which exhibit DYRK1B amplification) DYRK1B drives Thr286 phosphorylation and proteasome-dependent turnover of CCND1 and this is abolished by AZ191 or DYRK1B RNAi, but not by GSK3β inhibitors or GSK3β RNAi. DYRK1B expression causes a G1-phase cell-cycle arrest, but overexpression of CCND1 (wild-type or T286A) fails to overcome this; indeed, DYRK1B also promotes the expression of p21CIP1 (21 kDa CDK-interacting protein 1) and p27KIP1 (CDK-inhibitory protein 1). The results of the present study demonstrate for the first time that DYRK1B is a novel Thr286-CCND1 kinase that acts independently of GSK3β to promote CCND1 degradation. Furthermore, we anticipate that AZ191 may prove useful in defining further substrates and biological functions of DYRK1B.
A novel RCE1 isoform is required for H-Ras plasma membrane localization and is regulated by USP17
Authors: Jaworski Jakub , Govender Ureshnie , McFarlane Cheryl , de la Vega Michelle , Greene Michelle K. , Rawlings Neil D. , Johnston James A. , Scott Christopher J. , Burrows James F.
Published: October 2013

Processing of the ‘CaaX’ motif found on the C-termini of many proteins, including the proto-oncogene Ras, requires the ER (endoplasmic reticulum)-resident protease RCE1 (Ras-converting enzyme 1) and is necessary for the proper localization and function of many of these ‘CaaX’ proteins. In the present paper, we report that several mammalian species have a novel isoform (isoform 2) of RCE1 resulting from an alternate splice site and producing an N-terminally truncated protein. We demonstrate that both RCE1 isoform 1 and the newly identified isoform 2 are required to reinstate proper H-Ras processing and thus plasma membrane localization in RCE1-null cells. In addition, we show that the deubiquitinating enzyme USP17 (ubiquitin-specific protease 17), previously shown to modulate RCE1 activity, can regulate the abundance and localization of isoform 2. Furthermore, we show that isoform 2 is ubiquitinated on Lys43 and deubiquitinated by USP17. Collectively, the findings of the present study indicate that RCE1 isoform 2 is required for proper ‘CaaX’ processing and that USP17 can regulate this via its modulation of RCE1 isoform 2 ubiquitination.
Novel recirculating loop reactor for studies on model catalysts: CO oxidation on Pt/TiO2(110)
Authors: Tenney Samuel A. , Xie Kangmin , Monnier John R. , Rodriguez Abraham , Galhenage Randima P. , Duke Audrey S. , Chen Donna A.
Published: October 2013

A novel recirculating loop microreactor coupled to an ultrahigh vacuum (UHV) chamber has been constructed for the kinetic evaluation of model catalysts, which can be fully characterized by UHV surface science techniques. The challenge for this reactor design is to attain sufficient sensitivity to detect reactions on model single-crystal surfaces, which have a low number of active sites compared to conventional catalysts of equivalent mass. To this end, the total dead volume of the reactor system is minimized (32 cm3), and the system is operated in recirculation mode so that product concentrations build up to detectable levels over time. The injection of gas samples into the gas chromatography column and the refilling of the recirculation loop with fresh feed gas are achieved with computer-controlled, automated switching valves. In this manner, product concentrations can be followed over short time intervals (15 min) for extended periods of time (24 h). A proof of principle study in this reactor for CO oxidation at 145–165 °C on Pt clusters supported on a rutile TiO2(110) single crystal yields kinetic parameters that are comparable to those reported in the literature for CO oxidation on Pt clusters on powdered oxide supports, as well as on Pt(100). The calculated activation energy is 16.4 ± 0.7 kcal/mol, the turnover frequency is 0.03–0.06 molecules/(site·s) over the entire temperature range, and the reaction orders in O2 and CO at 160 °C are 0.9 ± 0.2 and −0.82 ± 0.03, respectively.
Installation of a versatile multiaperture negative ion source
Authors: Cavenago M. , Serianni G. , Antoni V. , Barbisan M. , Bigi M. , De Muri M. , Fagotti E. , Fellin F. , Kulevoy T. , Minarello A. , Pasqualotto R. , Petrenko S. , Poggi M. , Recchia M. , Rossetto F. , Sattin M. , Valente M. , Veltri P.
Published: October 2013

Neutral Beam Injectors (NBI), which need to be strongly optimized in the perspective of DEMO reactor, request a thorough understanding of the negative ion source used and of the multi-beamlet optics. A relatively compact RF ion source, named NIO1 (Negative Ion Optimization 1), with 9 beam apertures for a total H− current of 130 mA, 60 kV acceleration voltage, is being installed at Padua, in Consorzio RFX, to provide a test bench for source optimizations in the framework of the accompanying activities in support to the ITER NBI test facility. NIO1 construction and status of the overall installation, including a high voltage deck and an optical cavity ring down spectrometer are here summarized and reported. Plasma and low voltage beam operations are discussed. Development of a sampling beam calorimeter (with small sampling holes, and a segmented cooling circuit) is also discussed.
Exciton annihilation as bimolecular loss in organic solar cells
Authors: Tzabari Lior , Zayats Victoria , Tessler Nir
Published: October 2013

The dependence of the internal quantum efficiency of P3HT:PCBM (Poly(3-hexylthiophene-2,5-diyl) :[6,6]-Phenyl C61 butyric acid methyl ester) solar cell on light intensity was measured over four orders of magnitude and for devices annealed for 4 and 10 min. We find that both trap assisted (Shockley-Read-Hall type) and bimolecular losses coexist, the relative magnitude of which is dependent on both the light intensity and the processing conditions. We suggest that the use of Langevin type charge recombination in conjunction with trap assisted recombination is not the best choice and show that the well-known exciton annihilation by charge polaron may better account for the bimolecular losses.
Pin-wheel hexagons: A model for anthraquinone ordering on Cu(111)
Authors: Šimėnas M. , Tornau E. E.
Published: October 2013

The 4-state model of anthraquinone molecules ordering in a pin-wheel large-pore honeycomb phase on Cu(111) is proposed and solved by Monte Carlo simulation. The model is defined on a rescaled triangular lattice with the lattice constant a being equal to intermolecular distance in the honeycomb phase. The pin-wheel triangle formations are obtained taking into account the elongated shape of the molecules and anisotropic interactions for main two attractive short range (double and single dimeric) H-bond interactions. The long-range intermolecular interactions, corresponding to repulsive dipole-dipole forces, are assumed to be isotropic. Also, a very small (compared to short-range forces) isotropic attractive long-range interaction at the “characteristic” distance of a pore diameter is employed, and its effect carefully studied. This interaction is crucial for a formation of closed porous ordered systems, pin-wheel hexagons in particular. If each side of a pin-wheel hexagon is formed of n parallel molecules, the distance of this characteristic interaction is \documentclass[12pt]{minimal}\begin{document}$a\sqrt{3n^2+1}$\end{document}a3n2+1. The phase diagrams including different pin-wheel hexagon phases and a variety of other ordered structures are obtained. By changing the distance of characteristic interaction, different ordering routes into the experimental pin-wheel honeycomb phase are explored. The results obtained imply that classical explanation of the origin of the pin-wheel honeycomb phase in terms of some balance of attractive and repulsive forces cannot be totally discounted yet.
Theoretical studies of the passivants’ effect on the SixGe1-x nanowires: Composition profiles, diameter, shape, and electronic properties
Authors: Yang Xiao-Bao , Zhao Yu-Jun , Xu Hu
Published: October 2013

Theoretically, we have performed a systematic investigation on the passivants’ effect on the geometrical and electronic properties of SixGe1-x nanowires. First-principles calculations revealed that, in the nanowires passivated by fluorine (F)/chlorine (Cl)/hydrogen (H) atoms, Si atoms preferred to segregate towards the surface due to the stronger Si–X bonds than that of Ge–X bonds (X = F, Cl, H). The energy barriers of X atoms’ desorption is higher than that of the Si/Ge atoms’ exchanging, inducing a feasible and strong surface segregation of Si atoms at proper temperature. Considering the Si/Ge interactions and mixing entropy, the composition profiles of Si/Ge distributions are obtained by minimizing the Gibbs free energy, which indicates the outmost layer of surface should be mostly occupied by Si. With total Si surface segregation, the diameter and shape of most stable SixGe1-x nanowires are found to be determined by the composition x and the passivants’ chemical potential. In addition, charge distribution of near-gap levels can be modulated through the surface passivants. Our finding provides a practical avenue to tune the electronic properties of SixGe1-x nanowires, by modulating the morphologies of nanowires with the composition control of Si/Ge and the chemical potential of passivants.
Ultrafast light scattering imaging of multi-scale transition dynamics in vanadium dioxide
Authors: Lysenko Sergiy , Fernández Felix , Rúa Armando , Liu Huimin
Published: October 2013

Ultrafast hemispherical angle-resolved light scattering technique is applied to monitor the insulator-to-metal phase transition of highly oriented VO2 crystalline films, where transition is induced by femtosecond laser pulses. This approach reveals principal differences in transient dynamics of multi-scale VO2 grains for thermally and light-induced phase transformation, showing anisotropic and grain-size-dependent behavior with high resolution in space and time. Complete photoinduced transition occurs within 500 fs. However, VO2 grains of different sizes show different transition rates. The highest rate is found for clusters with lower concentration of structural defects and deformations. The twinning process in VO2 film is considerable for the thermally induced transition but is not detected for the ultrafast light-induced one.
Injection terahertz laser using the resonant inter-layer radiative transitions in double-graphene-layer structure
Authors: Ryzhii V. , Dubinov A. A. , Aleshkin V. Ya. , Ryzhii M. , Otsuji T.
Published: October 2013

We propose and substantiate the concept of terahertz (THz) laser enabled by the resonant electron radiative transitions between graphene layers (GLs) in double-GL structures. We estimate the THz gain for TM-mode exhibiting very low Drude absorption in GLs and show that the gain can exceed the losses in metal-metal waveguides at the low end of the THz range. The spectrum of the emitted photons can be tuned by the applied voltage. A weak temperature dependence of the THz gain promotes an effective operation at room temperature.
Investigation of deep-level defects in Cu(In,Ga)Se2 thin films by two-wavelength excitation photo-capacitance spectroscopy
Authors: Hu Xiaobo , Gupta Amit , Sakurai Takeaki , Yamada Akimasa , Ishizuka Shogo , Niki Shigeru , Akimoto Katsuhiro
Published: October 2013

The properties of the defect level located 0.8 eV above the valence band in Cu(In1−x,Gax)Se2 thin films were investigated by a photo-capacitance method using a monochromatic probe light with an energy of 0.7 to 1.8 eV. In addition to the probe light, laser light with a wavelength of 1.55 μm, corresponding to 0.8 eV, was also used to study the saturation effect of the defect level at 0.8 eV. A suppression of electron-hole recombination due to saturation of the defect level was observed at room temperature while no saturation effect was observed at 140 K. The results suggest that the defect level at 0.8 eV acts as a recombination center at least at room temperature.
Single hole transport in a silicon metal-oxide-semiconductor quantum dot
Authors: Li R. , Hudson F. E. , Dzurak A. S. , Hamilton A. R.
Published: October 2013

We describe a planar silicon metal-oxide-semiconductor (MOS) based single hole transistor, which is compatible with conventional Si complementary MOS fabrication. A multi-layer gate design gives independent control of the carrier density in the dot and reservoirs. Clear Coulomb blockade oscillations are observed, and source-drain biasing measurements show that it is possible to deplete the dot down to the few hole regime, with excited states clearly visible. The architecture is sufficiently versatile that a second hole dot could be induced adjacent to the first one.
Reversible collisionless magnetic reconnection
Authors: Ishizawa A. , Watanabe T.-H.
Published: October 2013

Reversible magnetic reconnection is demonstrated for the first time by means of gyrokinetic numerical simulations of a collisionless magnetized plasma. Growth of a current-driven instability in a sheared magnetic field is accompanied by magnetic reconnection due to electron inertia effects. Following the instability growth, the collisionless reconnection is accelerated with development of a cross-shaped structure of current density, and then all field lines are reconnected. The fully reconnected state is followed by the secondary reconnection resulting in a weakly turbulent state. A time-reversed simulation starting from the turbulent state manifests that the collisionless reconnection process proceeds inversely leading to the initial state. During the reversed reconnection, the kinetic energy is reconverted into the original magnetic field energy. In order to understand the stability of reversed process, an external perturbation is added to the fully reconnected state, and it is found that the accelerated reconnection is reversible when the deviation of the E × B streamlines due to the perturbation is comparable with or smaller than a current layer width.
Surface electronic structure of nitrogen-doped semiconducting single-walled carbon nanotube networks
Authors: Ran Park Young , Jae Ko Min , Song Yoon-Ho , Jin Lee Cheol
Published: October 2013

We investigated the effects of vacuum annealing on the surface electronic structure and the work function of single-walled carbon nanotubes (SWCNTs). We changed the doping type of semiconducting single-walled carbon nanotubes (semi-SWCNTs) from p-type to n-type, and investigated their optical properties. The HNO3 treated p-type SWCNT network was converted to n-type after vacuum annealing due to formation of C-N bond. The C 1s sp2 binding energy of the vacuum annealed semi-SWCNTs was shifted toward a higher binding energy about 0.42 eV, which indicates a raising Fermi level as much as 0.42 eV compared with the intrinsic semi-SWCNTs. In addition, the work function of the vacuum annealed semi-SWCNT was observed towards lower energies. It is considered that the C-N bonding of semi-SWCNTs creates a donor level near the bottom of the conduction band, thus raising the Fermi level. The ultraviolet photoelectron spectroscopy and X-ray photoelectron spectroscopy revealed that the increased binding energy of C 1s sp2 and the decreased work function of semi-SWCNTs are caused by n-type doping after vacuum annealing.
Focused cathode design to reduce anode heating during vircator operation
Authors: Lynn Curtis F. , Dickens James C. , Neuber Andreas A.
Published: October 2013

Virtual cathode oscillators, or vircators, are a type of high power microwave device which operates based on the instability of a virtual cathode, or cloud of electrons, which forms when electron current injected into the drift tube exceeds the space charge limited current within the drift tube. Anode heating by the electron beam during vircator operation ultimately limits achievable pulse lengths, repetition rates, and the duration of burst mode operation. This article discusses a novel cathode design that focuses electrons through holes in the anode, thus significantly reducing anode heating by the electrons emitted from the cathode during the first transit through the A-K gap. Reflexing electrons continue to deposit energy on the anode; however, the discussed minimization of anode heating by main beam electrons has the potential to enable higher repetition rates as well as efficiency and longer diode lifetime. A simulation study of this type of cathode design illustrates possible advantages.
Graphene nanoribbon thermopower as a tool for molecular spectroscopy
Authors: Rosales L. , Nunez C. D. , Pacheco M. , Latgé A. , Orellana P. A.
Published: October 2013

In this work, we study thermoelectric properties of graphene nanoribbons with side-attached organic molecules. By adopting a single-band tight binding Hamiltonian and the Green's function formalism, we calculated the transmission and Seebeck coefficients for different hybrid systems. The corresponding thermopower profiles exhibit a series of sharp peaks at the eigenenergies of the isolated molecule indicating that the system can be proposed as a molecular thermo-device. We have studied the effects of the temperature on the thermoelectric response, and considered random configurations of molecule distributions, in different disorder regimes. We have found that the main features of the thermopower are robust under temperature and disorder.
Photon-induced thermal effects in superconducting coplanar waveguide resonators
Authors: Wang Yiwen , Zhou Pinjia , Wei Lianfu , Li Haijie , Zhang Beihong , Zhang Miao , Wei Qiang , Fang Yurong , Cao Chunhai
Published: October 2013

We experimentally investigated the optical responses of a superconducting niobium resonator. It was found that, with increasing radiation power, the resonance frequency increases monotonically below around 500 mK, decreases monotonically above around 1 K, and exhibits a nonmonotonic behavior at around 700 mK. These observations show that one can operate the irradiated resonator in three temperature regimes, depending on whether two-level system (TLS) effects or kinetic inductance effects dominate. Furthermore, we found that the optical responses at ultra-low temperatures can be qualitatively regarded as a photon-induced thermalization effect of TLSs, which could be utilized to achieve thermal sensitive photon detections.
Contact potential induced enhancement of magnetization in polyaniline coated nanomagnetic iron oxides by plasma polymerization
Authors: Sethulakshmi N. , Sooraj V. , Sajeev U. S. , Nair Swapna S. , Narayanan T. N. , Joy Lija K. , Joy P. A. , Ajayan P. M. , Anantharaman M. R.
Published: October 2013

The present work derives motivation from the so called surface/interfacial magnetism in core shell structures and commercial samples of Fe3O4 and γ Fe2O3 with sizes ranging from 20 to 30 nm were coated with polyaniline using plasma polymerization and studied. The High Resolution Transmission Electron Microscopy images indicate a core shell structure after polyaniline coating and exhibited an increase in saturation magnetization by 2 emu/g. For confirmation, plasma polymerization was performed on maghemite nanoparticles which also exhibited an increase in saturation magnetization. This enhanced magnetization is rather surprising and the reason is found to be an interfacial phenomenon resulting from a contact potential.
Enhancement of proton energy by polarization switch in laser acceleration of multi-ion foils
Authors: Liu Tung-Chang , Shao Xi , Liu Chuan-Sheng , Eliasson Bengt , Wang Jyhpyng , Chen Shih-Hung
Published: October 2013

We present a scheme to significantly increase the energy of quasi-monoenergetic protons accelerated by a laser beam without increasing the input power. This improvement is accomplished by first irradiating the foil several wave periods with circular polarization and then switching the laser to linear polarization. The polarization switch increases the electron temperature and thereby moves more electrons ahead of the proton layer, resulting in a space charge electric field pushing the protons forwards. The scaling of the proton energy evolution with respect to the switching time is studied, and an optimal switching time is obtained. The proton energy for the case with optimal switching time can reach about 80 MeV with an input laser power of 70 TW, an improvement of more than 30% compared to the case without polarization switch.
Breakdown point of quantum confinement photoluminescence and space-separation dependent energy transfer from silicon nanocrystals
Authors: Li Yonglei , Qian Bo , Sui Zhanpeng , Jiang Chunping
Published: October 2013

A detailed photoluminescence (PL) analysis and transmission electron microscopy studies on silicon nanocrystals (SNCs) are presented to probe the carrier recombination mechanism. There exist obvious distinctive phenomena in different sizes of SNCs. Clear evidence for the breakdown point of quantum confinement PL is confirmed in small SNCs; it is regarded as inflection point for SNCs' corresponding electronic states. Moreover, the energy-transfer based carrier multiplication and SNCs nanotwin are also observed between neighboring nanocrystals in large ones. Finally, a systematic model has been proposed to explain the evolution of SNCs' PL mechanism along with the size and space-separation of SNCs.
Diode behavior in ultra-thin low temperature ALD grown zinc-oxide on silicon
Authors: El-Atab Nazek , Alqatari Samar , Oruc Feyza B. , Souier Tewfic , Chiesa Matteo , Okyay Ali K. , Nayfeh Ammar
Published: October 2013

A thin-film ZnO(n)/Si(p+) heterojunction diode is demonstrated. The thin film ZnO layer is deposited by Atomic Layer Deposition (ALD) at different temperatures on a p-type silicon substrate. Atomic force microscopy (AFM) AC-in-Air method in addition to conductive AFM (CAFM) were used for the characterization of ZnO layer and to measure the current-voltage characteristics. Forward and reverse bias n-p diode behavior with good rectification properties is achieved. The diode with ZnO grown at 80°C exhibited the highest on/off ratio with a turn-on voltage (VON) ∼3.5 V. The measured breakdown voltage (VBR) and electric field (EBR) for this diode are 5.4 V and 3.86 MV/cm, respectively.
Multiple-interface tracking of degradation process in organic photovoltaics
Authors: Zhao Cindy X. , Deng Lucy L. , Ma Matthew Y. , Kish Joseph R. , Xu Gu
Published: October 2013

The investigation of the stability in organic photovoltaics has been focused on individual components via localized and destructive analysis, which is limited to broken devices, instead of an operational OPV, and unable to obtain correlated information of degrading interfaces. DC biased AC impedance spectroscopy is employed here, to track multi-interface degradation without breaking the device. By varying DC bias, individual interface degradation is revealed via current density and capacitance versus voltage plots. While one of the impedance semicircles is linked to the interface of P3HT:PCBM, the other represented the interface between the mixture and metal electrode, involving metal oxide in an aged device. The results confirm that, more than one degradation process take place simultaneously at individual interfaces.
Effects of bushfire on macroinvertebrate communities in south-east Australian streams affected by a megadrought
Authors: Verkaik I. , Prat N. , Rieradevall M. , Reich P. , Lake P. S.
Published: October 2013

Bushfires occur in most environments in Australia and yet there are few studies about fire effects on aquatic ecosystems. To study the effects of fire on aquatic macroinvertebrates we sampled three streams in burnt catchments (i.e. burnt) and three streams in unburnt catchments (i.e. control), nine months after severe bushfires in northern Victoria. The sampling period coincided with a severe and prolonged period of drought – during the 8th year of a series of thirteen consecutive years of below average rainfall. There was a significant effect of bushfire on macroinvertebrate richness, composition and function. At the burnt sites, there was lower taxon richness but a 4-fold increase in abundance, which was mainly to the result of increases in taxa such as Chironomidae, Simuliidae, Dinotoperla sp. and Taschorema sp. A higher percentage of gathering collectors was found at the burnt sites, whereas scrapers and shredders were co-dominant in the control streams. The responses of the macroinvertebrates may have been impaired by post-fire persistence of low flows associated with the continuing drought, in comparison with the rapid recovery of the catchment overstorey vegetation (Eucalyptus spp.). The consequences of the megadrought combined with catchment bushfires, have no doubt reduced the resilience of the macroinvertebrate communities.
Habitat requirements and spawning strategy of an estuarine-dependent fish, Percalates colonorum
Authors: van der Meulen Dylan E. , Walsh Chris T. , Taylor Matthew D. , Gray Charles A.
Published: October 2013

Determining the links among estuarine hydrography, habitat and spawning of estuarine-dependent fish is essential for understanding reproductive dynamics, recruitment processes and directing conservation efforts. Acoustic tracking was used to evaluate fine-scale spatial and temporal patterns in spawning activity of Percalates colonorum (estuary perch) within the Shoalhaven River, south-eastern Australia. Plankton tows were used to determine the timing of spawning events. Tagged P. colonorum exhibited movements restricted to areas of structurally complex large wooden debris and a concrete ferry landing. Egg counts confirmed that spawning events coincided with adult aggregations, whereas egg abundances peaked at night during the first 2 h of the run-out tide. We postulate that spawning and recruitment success of P. colonorum is attributable to its selective spawning habitats that are (1) structurally complex to provide refuge and protection from predation, as well as congregate prey items, (2) adjacent to deep water of high velocities to maximise egg dispersal and (3) in close proximity to river entrance to facilitate coastal dispersal of eggs and inter-estuarine connectivity of larvae.
Ontogenetic patterns of growth and lipid composition changes of blue swimmer crab larvae: insights into larval biology and lipid nutrition
Authors: Wu X. G. , Zeng C. S. , Southgate P. C.
Published: October 2013

Blue swimmer crab, Portunus pelagicus, is a commercially important crab throughout the Indo-Pacific region, that plays an important role in the food chains of coastal ecosystems. P. pelagicus undergoes four pelagic zoeal stages and a post-larval megalopal stage before settling as benthic juvenile; however, very limited information is available on larval biology and lipid nutrition of this species. The present comprehensive study investigated survival, growth and ontogenetic changes in lipid composition of P. pelagicus larvae under laboratory conditions. Larvae were fed rotifers (zoea I), rotifers and Artemia (zoea II) and enriched Artemia (zoea III – megalopa), consecutively. Among five larval stages of P. pelagicus, zoea I and II had the shortest durations (2.2–2.3 days), whereas megalopa had the longest duration (4.7 days). As larvae developed, their wet weight, dry weight and carapace length increased exponentially. Lower mortality occurred during zoea II (12.5%) and zoea III (14.3%), coincidental with the lower percentage increments in dry weight and specific growth rate of dry weight during these two stages. Generally, fatty acid composition of larvae can reflect that of their diets. However, increases in mono-unsaturated fatty acids, 20 : 4n-6 and 22 : 6n-3 in megalopa and the first crab compared with zoea IV might suggest that the later larvae were still deficient in essential fatty acids, and that 20 : 4n-6 and 22 : 6n-3 were preferentially accumulated. Therefore, measures of ontogenetic patterns of growth and lipid composition will provide valuable insights for better understanding of larval biology and lipid nutrition of P. pelagicus.
Variability in groundwater depth and composition and their impacts on vegetation succession in the lower Heihe River Basin, north-western China
Authors: Zhu JunTao , Yu JingJie , Wang Ping , Yu Qiang , Eamus Derek
Published: October 2013

Plant-community structure and groundwater attributes were investigated in Ejina Delta in north-western China to understand spatial variability of groundwater depth and composition and their impacts on vegetation succession. Geostatistical methods and ordination analysis were performed to analyse the data. In addition, we tried to obtain vegetation successional series by using an approach of spatial sequences instead of temporal sequences. The findings of the present study were as follows: (1) the coefficient of variation for groundwater depth (GWD), salinity (SAL), total dissolved solids (TDS), electrical conductivity (EC), pH, Ca2+, Mg2+, K+, Na+, SO42–, HCO3–, NO3–, Cl– and F– ranged from 0.04 to 1.53; (2) GWD, Mg2+, TDS, EC, Ca2+, HCO3–, NO3– and pH showed strong spatial autocorrelation, whereas K+ and SAL showed moderate spatial autocorrelation; (3) canonical correspondence analysis revealed that groundwater heterogeneity, especially GWD, followed by pH, SAL, TDS, EC and HCO3–, had an important impact on vegetation succession, and thus showed a prevalence of groundwater attributes-based niche differentiation among plant communities; and (4) there were two vegetation successional processes (drought and salinisation) in the lower Heihe River Basin, and salinisation processes increased with drought processes. Our results indicated that high spatial variability of groundwater attributes contributes to promoting maintenance of species and landscape diversity in the lower Heihe River Basin.