bluuebunny/crossref_metadata_2025 huggingface dataset:
Compositionally tunable three-dimensional nano-seeding assembly in Fe–LaSrFeO4 nanostructure
Authors: Okada K. , Tanaka H.
Published: February 2013

We demonstrate that a combined method for producing a compositionally tuned self-assembled three-dimensional (3D) nano-seeding assembly can change the nanostructure of an Fe–LaSrFeO4 nanocomposite. We found that the area density, diameter, and height of Fe nanodots were significantly influenced by tuning the contents of Fe and LaSrFeO4. The compositionally tuned self-assembly was used for 3D nano-seeding assembly. As a result, bilayer Fe nanodots, which were not obtained using ordinary self-assembled growth, were formed, at low Fe contents. Large dome−shaped Fe nanodots were grown on Fe nanoseeds with high Fe contents. Magnetic force microscopy measurements revealed that the magnetic properties of an Fe nanodot surrounded by an LaSrFeO4 matrix can be controlled by changing the aspect ratio through compositional tuning. This combined route could expand the use of self-assembled nanocomposites for future nanotechnological applications.
Charge transport in lightly reduced graphene oxide: A transport energy perspective
Authors: Kajen R. S. , Chandrasekhar N. , Pey K. L. , Vijila C. , Jaiswal M. , Saravanan S. , Ng Andrew M. H. , Wong C. P. , Loh K. P.
Published: February 2013

Significant variation in the charge transport behaviour in graphene oxide (GO) ranging from Schottky to Poole-Frenkel and to space charge limited transport exists. These have been extensively reported in the literature. However, the validity of such conventional charge transport models meant for delocalized carriers, to study charge transport through localised states in GO, a disordered semiconductor is open to question. In this work, we use the concept of transport energy (TE) to model charge transport in lightly reduced GO (RGO) and demonstrate that the TE calculations match well with temperature dependent experimental I-V data on RGO. We report on a temperature dependent TE ranging from a few 10 meV to 0.1 eV in slightly reduced GO. Last, we point out that, despite the success of several delocalised charge transport models in estimating barrier heights that resemble the TE level, they remain largely accidental and lack the insight in which the TE concept provides in understanding charge transport in RGO.
Study on phosphor sedimentation effect in white light-emitting diode packages by modeling multi-layer phosphors with the modified Kubelka-Munk theory
Authors: Hu Run , Wang Yiman , Zou Yong , Chen Xing , Liu Sheng , Luo Xiaobing
Published: February 2013

In this study, we studied the phosphor sedimentation effect in white phosphor-converted light-emitting diode packages by modeling the multi-layer phosphors with gradient concentrations. The essence of phosphor sedimentation can attribute to the variation of phosphor concentrations. By modifying the Kubelka-Munk theory, we built a multi-layer phosphor model with considering the light scattering, light absorption, and light conversion process simultaneously. With a brief review of Kubelka-Munk theory, multi-layer phosphors were modeled on the basis of single-layer phosphor model. The phosphor sedimentation effect was characterized by modeling multi-layer phosphors with gradient concentrations, whereas keeping the total amount of phosphors at the same level. It is found from the five calculation cases that phosphor sedimentation will cause the drop of light extraction efficiency (LEE) by 13.04%. Furthermore, the phosphor layer with inverse-gradient concentrations will enhance the LEE 16.56%. To figure out the reasons, the light losses were calculated, and it is proved that the light loss is enhanced when phosphor sedimentation happens.
Acceleration and dynamics of an electron in the degenerate and magnetized plasma elliptical waveguide
Authors: Abdoli-Arani A. , Jazi B. , Shokri B.
Published: February 2013

The dynamics and energy gain of an electron in the field of a transverse magnetic wave propagating inside an elliptical degenerate plasma waveguide is analytically investigated by finding the field components of the TMmr mode in this waveguide. Besides, by solving the relativistic momentum and energy equations the deflection angle and the acceleration gradient of the electron in the waveguide are obtained. Furthermore, the field components of the hybrid mode and the transferred power in the presence of the magnetic field in this waveguide are found. Also by applying the boundary conditions at the plasma-conductor interface, we calculate the dispersion relation. It is shown that the cutoff frequency of this mode is dependent on the plasma density but independent of the magnetic field. Then, a single-electron model for numerical calculations of the electron deflection angle and acceleration gradient inside the magnetized plasma-filled elliptical waveguide is generally presented to be used as a cascading process for the acceleration purposes.
Thermally activated magnetization switching in a nanostructured synthetic ferrimagnet
Authors: Min Lee Jong , Ho Lim Sang
Published: February 2013

Thermally activated magnetization switching in a nanostructured synthetic ferrimagnet is investigated by micromagnetic simulations and results are analyzed using the Arrhenius-Néel formula. In most of the previous studies, the characteristic attempt time was assumed to be fixed and the parameter extracted from the analysis was the magnetic energy barrier. In this study, however, the assumption of a fixed characteristic attempt time was not used, with resultant advantages of extracting the characteristic attempt time from the analysis and of critically testing the validity of the formula. This was made possible with a precise analytical description of the magnetic field dependence of the energy barrier in the synthetic ferrimagnet. The thermally activated magnetization switching behavior is found to be well described by the Arrhenius-Néel formula with a well-defined characteristic attempt time of 3.1 ns.
Resonant Raman scattering from CdS nanocrystals enhanced by interstitial Mn
Authors: Zhao P. Q. , Liu L. Z. , Xue H. T. , Wu X. L. , Shen J. C. , Chu Paul K.
Published: February 2013

Different Raman scattering effects are observed from CdS and Mn-doped CdS nanocrystals (NCs) with an average size of 5.1 nm synthesized by the reverse-micelle method. The intensity of the longitudinal optical (LO) phonon spectrum acquired from the Mn-doped CdS NCs is more than 20 times larger than that from the undoped CdS NCs. Spectroscopic and theoretical analyses reveal that the enhancement is caused by the interstitial Mn dopants, which decrease the NC surface deformation potential due to the small dielectric constant of the metal resulting in enhanced coupling between the LO phonon and surface plasmon.
Effects of holmium substitution on multiferroic properties in Tb0.67Ho0.33MnO3
Authors: Staruch M. , Lawes G. , Kumarasiri A. , Cotica L. F. , Jain M.
Published: February 2013

In this work, the structural, electrical, and magnetic properties of orthorhombic TbMnO3 and Tb0.67Ho0.33MnO3 ceramics are presented. The lattice parameters and the Mn-O-Mn bond angle were found to decrease with Ho-substitution as evidenced by Rietveld refinement of the X-ray diffraction data and Raman spectroscopy measurements. A weak ferromagnetic moment was observed in both dc and ac magnetic measurements of the Ho-substituted sample possibly due to spin canting in the antiferromagnetic phase. Tb0.67Ho0.33MnO3 was confirmed to be multiferroic with appearance of spontaneous polarization below 25 K and an additional increase in polarization ∼15.5 K associated with the ordering of the Ho3+ moments.
Fast switching protocol for ferroelectric random access memory based on poly(vinylidene fluoride-trifluoroethylene) copolymer ultrathin films
Authors: Hou Ying , Lü Zhaoyue , Pu Tiansong , Zhang Yuan , Xu Guoqiang , Xu Haisheng
Published: February 2013

The polarization switching behaviors with different pulse processes for ferroelectric poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer ultrathin films have been studied. The faster switching speed with imprint time is observed for the films with the certain switching and imprint directions. The internal electric fields for these processes are well analyzed, and it is found that the effective fields as well as charge trap states in ferroelectric layers are strongly responsible for the switching behaviors. This result provides an effective route to design the optimum protocol for ferroelectric random access memory based on P(VDF-TrFE) copolymer ultrathin film.
Studies of carrier recombination in solution-processed CuIn(S,Se)2 through photoluminescence spectroscopy
Authors: Duan Hsin-Sheng , Tang Kuo-Chun , Hsu Wan-Ching , Bob Brion , Song Tze-Bin , Lei Bao , Chou Pi-Tai , Yang Yang
Published: February 2013

We investigated the effects of the cadmium sulfide (CdS) layer on defect passivation in hydrazine-based CuIn(S,Se)2 (CISSe) samples through photoluminescence measurements. Significant changes in the emission profile of the CISSe film are observed after a CdS layer is deposited on CISSe. It is likely that Cd diffusion into the CISSe film becomes more severe as a result of the fine grain size of our solution-processed films. Enhanced emission yields and longer carrier lifetimes are, thus, observed in Cd-treated (CdS-coated or Cd-soaked) CISSe films, indicating the action of Cd ions on Cu vacancies sites and a decrease in non-radiative recombination.
Pulsed-laser deposited Pb(Zr0.52,Ti0.48)O3-on-silicon resonators with high-stopband rejection using feed-through cancellation
Authors: Yagubizade H. , Darvishi M. , Chen Y.-Y. , Nguyen M. D. , Dekkers J. M. , Wiegerink R. J. , Elwenspoek M. C. , Tas N. R.
Published: February 2013

A length extensional mode lead zirconate titanate (PZT)-on-Si resonator is presented using 50 Ω termination with high-stopband rejection exploiting feed-through cancellation. A 250-nm-thick (100)-dominant oriented PZT thin-film deposited on top of 3 μm Si using pulsed laser deposition has been used. The resonator is presented with the length of 40 μm (half-wavelength), which corresponds to a resonance frequency of about 83 MHz. The effect of feed-through cancellation has been studied to obtain high-stopband rejection using bottom electrode patterning in the presence of a specific grounding resistance. Using this technique, the stopband rejection can be improved by more than 20 dB.
The Production of Space: A Neglected Perspective in Pastoral Research
Authors: Karplus Yuval , Meir Avinoam
Published: February 2013

This paper offers an overview of the dispersed elements of social spatiality present in the rich work about pastoralists and their space, and brings them together under the conceptual framework of Lefebvre's production of space. The three facets of pastorally produced space are outlined: ‘perceived space’, low-intensity spatial footprints linked by seasonal migratory trails; ‘conceived space’, social territoriality and agrarian socialism; and ‘lived space’, ideologies of spatial attachment that transcend a particular place. Based on this framework, we discuss and illustrate with case studies the relational aspects between pastoral economic, cultural, and political structures and their spatiality. We suggest that such an engagement highlights the reciprocal constitutive interaction between space and society and the coherent nature of the production of pastoral space. We argue that the extent to which pastoral spatial coherence can be maintained in the face of pressures from other, rival, and often more powerful spatialities is paramount to the sustainability of pastoralist existence.
Postcolonialising Informality?
Authors: Varley Ann
Published: February 2013

Urban informality has been the subject of renewed attention in recent years, with a resurgence of interest from architecture and planning. A focus on informality has however been criticised as reviving colonial hierarchies, characterising entire cities in terms of lack and rendering them perpetually inferior to Western cities. The call to postcolonialise urban studies has been answered by an emerging literature which has neglected Latin America. This paper therefore examines recent work on urban informality in the region that resonates with other scholarship at the intersection of postcolonial and urban studies. The Latin American work is characterised by an emphasis on informality as resistance and by challenges to the formal/informal binary. Its ‘favela-isation’ of the continent can however perpetuate dualistic interpretations, entrenching or inverting stereotypes rather than disrupting them. The paper also asks what postcolonial readings of informality from elsewhere can contribute to understanding Latin American experience.
Carceral Geography and the Spatialities of Prison Visiting: Visitation, Recidivism, and Hyperincarceration
Authors: Moran Dominique
Published: February 2013

Geography, as a disciplinary lens, brings a valuable perspective to the study of the carceral, and carceral geography's concern for the spatial could provide a new explanatory perspective to the consideration of some accepted tenets within criminology, whilst at the same time offering a productive and useful ‘grounding’ of contemporary geographies of emotion and affect. In the context of hyperincarceration and the carceral continuum of recidivism and repeated reimprisonment, this paper considers the long-observed relationship between prison visitation and reduced recidivism, posits prison visiting rooms as underresearched carceral spaces, and develops theoretical and methodological innovations which nuance the understanding of prison visiting.
Entrepreneurial Assemblages from off the Map: (Trans) National Designs for Tangier
Authors: Kanai J Miguel , Kutz William
Published: February 2013

Poststructuralist perspectives need to be reconciled with political economic readings of urban globalization. One approach complements the other: the enactment of distantiated circuits and the territorialization of flows occur within existing geographies of uneven development while contingently reproducing or reshaping such spatial conditions of possibility. We argue that broadening the realm of critical urbanism is particularly relevant for researching peripheral entrepreneurialisms and their inherent (im) mobilities, conspicuous ambition paired with unavoidable constraints. This paper focuses on Tanger City Center, a landmark redevelopment controversial for its exclusionary designs and troubled inception. Adopting mobile methods with relational perspectives, we retrace the translocal negotiation of this symptomatic assemblage. However, we show that its territorialization cannot be understood apart from the state-sponsored remaking of Tangier into an expansive yet also unequal and fragmented city-region. Furthermore, underneath globalist discourse, the assemblage evinces circumscribed (trans)national agency at the planning stage, while subsequent frictions and disruptions punctuate the construction rhythm. Alongside its theoretical thrust, the paper contributes to: (a) the advancement of explicitly urban interpretations of globalization of the Middle East and North Africa, particularly Morocco's emerging neoliberal geographies under King Mohammed VI; and (b) the diversification of narratives of globalization-led urban change by theorizing entrepreneurial predicaments from off the map of global city imaginations.
Playing with the Line, Channelling Multiplicity: Wind Power Planning in the Narbonnaise (Aude, France)
Authors: Nadaï Alain , Labussière Olivier
Published: February 2013

This paper describes an innovative planning process, the Wind Power Charter of the Regional Natural Park of the Narbonnaise (southern France). By ‘innovative’, we mean that planners' decisions relate to the site/situation which they aim to transform rather than to preexisting norms or abstract territorial representations, as is so often the case in wind power planning processes. This planning process has a direct consequence: it succeeds in taking into account the existing local landscape and in engaging it in a transformative process. Drawing upon Deleuze's and Guattari's concepts of ‘map’/‘tracing’, and on Deleuze's concept of ‘sign’, we follow the way in which landscape is circulated in this process and analyse the relational properties of the graphic representations which underlie it. The analysis relies on a follow-up of the design and consultation work throughout this process. It shows how an iconographic practice can contribute to the composition of an emerging reality (new landscape) without indexing it to preexisting and normative representations of the territory: hence the title of the paper, “Playing with the line, channelling multiplicity”, which connects the materiality of graphic forms with the nonrepresentational—with the multiplicity of the emerging energy landscapes.
Decolonising Property: Exploring Ethics, Land, and Time, through Housing Interventions in Contemporary Australia
Authors: Crabtree Louise
Published: February 2013

The idea of property is a fundamental and foundational component of modern industrialised economies and yet, as a growing body of work shows, property is far from settled as a concept, or as a set series of relationships—whether between institutions, humans, places, and/or other species. Property systems are part of emergent, complex socioecological systems, reflecting and manifesting social and political phenomena, and asserting particular forms of citizen/self as acceptable, preferable and dominant. Predominant Western understandings of property rely on, enable, and anticipate increases in property value over time, reflecting particular conceptualisations and experiences of time shaped by Judeo—Christian teleological narratives in which time moves towards a perfect state that ironically remains perpetually imminent. This essay is concerned with tracing the ontological baggage of predominant understandings of property and time and exploring the terrain of their Others, as well as exploring the shifts in relationships between these in a decolonising and postmodern Australian context. This paper will reveal some of the diversity of what and how societies think about property and time, to suggest we may be starting—albeit 21—to acknowledge and engage with multiple and complex iterations of these.
Dissimulated Landscapes: Postcolonial Method and the Politics of Space in Southern Sri Lanka
Authors: Jazeel Tariq
Published: February 2013

This paper puts forward a broadly postcolonial method for engaging with landscapes in South Asia, in this case southern Sri Lanka. It argues that, as valuable as the familiar theoretical and conceptual languages of Euro-American landscape geography are, they also risk concealing a range of different aesthetics, social formations, and experiences that unfold in the non-Euro-American landscape. They risk dissimulating the politics of places as they are produced and lived contextually. In the paper I work this argument through a critical engagement of the landscape architecture of Sri Lanka's most famous tropical—modernist architect, Geoffrey Bawa; I specifically focus on his favorite, intensely choreographed, view at the estate Lunuganga on Sri Lanka's south coast. As I show, while tools from the new cultural geography and beyond can help us to read this view as a classically modernist and apolitical landscape, a work of ‘art for art's sake’, it is only a radically contextual familiarization with Sri Lankan society, politics, and history that can also reveal the landscape's more subtle instantiation of a spatializing Sinhala—Buddhist hegemony. Indeed, I show how some of the familiar (Eurocentric) concept-metaphors that we might intuitively bring to a reading of this landscape—namely ‘nature’, ‘religion’, and ‘ksubjectivity’—hold at arm's length particular kinds of landscape politics that emerge from differently textualized human relationships with the environment. The paper charts a method responsive to this particular landscape, and by doing so insists on the difficult task of retaining the singularity of landscapes positioned beyond the Euro-American staging grounds of the conceptual debates current within contemporary cultural geography.
Architectures of ‘the Good Life’: Queer Assemblages and the Composition of Intimate Citizenship
Authors: van Doorn Niels
Published: February 2013

This paper examines how the practices and events of queer collectivity might encourage us to think differently about the relationship between sexuality, intimacy, and citizenship. Through the exposition and discussion of four ‘scenes’ based on ethnographic engagements with various LGBT collectives in Baltimore, MD, it attends to the visceral and more-than-human registers in which a fragile sense of community comes into being, subsequently developing an understanding of intimacy as a transversal sphere of mutual investment in which political and civic practices can be cultivated. This entails an analytical shift from understanding citizenship as a ‘practice of claims’ within a (supra)national legal framework to its conceptualization as a ‘practice of composition’, which brings into relief the civic nature of collective efforts towards the creation and maintenance of safe environments that foster marginalized expressions of sexuality, gender, and pleasure. These attempts to experiment with new forms of belonging and ‘the good life’ are animated by the intimate associations, practices, and events that traverse public and private space—times. Ultimately, then, it is argued that intimacy is itself a proper mode of citizenship, one of its ‘regimes of enunciation’ that is folded into many contiguous others, and that a concern for the composition of ‘civic intimacies’ productively augments and complicates established research on intimate/sexual citizenship.
Effect of water stress on growth, water use efficiency and gas exchange as related to osmotic adjustment of two halophytes Atriplex spp.
Authors: Belkheiri Oumelkheir , Mulas Maurizio
Published: February 2013

Atriplex halimus L. is known in the Mediterranean basin and along the coastal areas of Sardinia for its adaptability to salinity, although less information is available on the resistance of this species to water stress in absence of salinity. The effect of water stress on growth and water utilisation was investigated in two Atriplex species: A. halimus originating of south Sardinian island and the exotic species Atriplex nummularia Lindl., originating in Australia and widely used in land restoration of arid areas. Water stress was applied to young plants growing in 20 L pots with a sufficient water reserve to store a potentially sufficient water reserve to maintain substrate near to field capacity (30%) between irrigations. Watering was at 70% (control) or 40% (stress) of field capacity. In order to simulate the grazing by livestock, four plant biomass cuttings were conducted at times T0, T1, T2 and T3, corresponding to one cutting at the end of well watered phase (T0) before water stress induction, two cuttings after cycles of 5 weeks each during full summer (T1) and late summer (T2) and one cutting during autumn (T3). All plants remained alive until the end of treatment although growth was strongly reduced. Leaf dry weight (DW) and water use efficiency (WUE) were determined for all cuttings; relative water content (RWC), turgid weight : dry weight ratio (TW : DW), water potential (Ψw), osmotic potential (Ψs), CO2 assimilation, osmotic adjustment (OA), abscisic acid (ABA) and sugar accumulation were determined for the late summer cutting at T2. Water stress induced a decrease in DW, RWC, Ψw, Ψs, TW : DW and CO2 assimilation for both species, but an increase in WUE expressed in terms of dry matter production and a high accumulation of ABA and total sugars mainly for A. halimus. This suggests a more developed adaptive mechanism in this selection. Indeed, the clone was selected from the southern part of the island, where natural populations of saltbush are more exposed to abiotic stresses, mainly the water stress generated not by salinity. A. nummularia showed a greater OA and a positive net solute accumulation as than A. halimus, suggesting that water stress resistance in A. halimus is linked to a higher WUE rather than a greater osmotic adjustment.
Pathways for Neoarchean pyrite formation constrained by mass-independent sulfur isotopes
Authors: Farquhar James , Cliff John , Zerkle Aubrey L. , Kamyshny Alexey , Poulton Simon W. , Claire Mark , Adams David , Harms Brian
Published: February 2013

It is generally thought that the sulfate reduction metabolism is ancient and would have been established well before the Neoarchean. It is puzzling, therefore, that the sulfur isotope record of the Neoarchean is characterized by a signal of atmospheric mass-independent chemistry rather than a strong overprint by sulfate reducers. Here, we present a study of the four sulfur isotopes obtained using secondary ion MS that seeks to reconcile a number of features seen in the Neoarchean sulfur isotope record. We suggest that Neoarchean ocean basins had two coexisting, significantly sized sulfur pools and that the pathways forming pyrite precursors played an important role in establishing how the isotopic characteristics of each of these pools was transferred to the sedimentary rock record. One of these pools is suggested to be a soluble (sulfate) pool, and the other pool (atmospherically derived elemental sulfur) is suggested to be largely insoluble and unreactive until it reacts with hydrogen sulfide. We suggest that the relative contributions of these pools to the formation of pyrite depend on both the accumulation of the insoluble pool and the rate of sulfide production in the pyrite-forming environments. We also suggest that the existence of a significant nonsulfate pool of reactive sulfur has masked isotopic evidence for the widespread activity of sulfate reducers in the rock record.
Strengthened glycolysis under hypoxia supports tumor symbiosis and hexosamine biosynthesis in pancreatic adenocarcinoma
Authors: Guillaumond Fabienne , Leca Julie , Olivares Orianne , Lavaut Marie-Noëlle , Vidal Nicolas , Berthezène Patrice , Dusetti Nelson Javier , Loncle Céline , Calvo Ezequiel , Turrini Olivier , Iovanna Juan Lucio , Tomasini Richard , Vasseur Sophie
Published: February 2013

Pancreatic ductal adenocarcinoma is one of the most intractable and fatal cancer. The decreased blood vessel density displayed by this tumor not only favors its resistance to chemotherapy but also participates in its aggressiveness due to the consequent high degree of hypoxia. It is indeed clear that hypoxia promotes selective pressure on malignant cells that must develop adaptive metabolic responses to reach their energetic and biosynthetic demands. Here, using a well-defined mouse model of pancreatic cancer, we report that hypoxic areas from pancreatic ductal adenocarcinoma are mainly composed of epithelial cells harboring epithelial-mesenchymal transition features and expressing glycolytic markers, two characteristics associated with tumor aggressiveness. We also show that hypoxia increases the “glycolytic” switch of pancreatic cancer cells from oxydative phosphorylation to lactate production and we demonstrate that increased lactate efflux from hypoxic cancer cells favors the growth of normoxic cancer cells. In addition, we show that glutamine metabolization by hypoxic pancreatic tumor cells is necessary for their survival. Metabolized glucose and glutamine converge toward a common pathway, termed hexosamine biosynthetic pathway, which allows O-linked N-acetylglucosamine modifications of proteins. Here, we report that hypoxia increases transcription of hexosamine biosynthetic pathway genes as well as levels of O-glycosylated proteins and that O-linked N-acetylglucosaminylation of proteins is a process required for hypoxic pancreatic cancer cell survival. Our results demonstrate that hypoxia-driven metabolic adaptive processes, such as high glycolytic rate and hexosamine biosynthetic pathway activation, favor hypoxic and normoxic cancer cell survival and correlate with pancreatic ductal adenocarcinoma aggressiveness.
The expression of the perfect in East and South-East Asian Englishes
Authors: Seoane Elena , Suárez-Gómez Cristina
Published: February 2013

This paper looks at variation in the expression of perfect meaning in Asian Englishes (Hong Kong, India, Singapore and the Philippines) as represented in the spoken component of the International Corpus of English. Findings confirm the existence of levelling between the present perfect and simple past in these varieties, and that the tendency of the present perfect to lose ground to the preterite is more pronounced in these New Englishes than in British English, especially in the expression of recent past. The occurrence of other variants in the corpus is accounted for in terms of the influence of the respective substrate languages, cognitive constraints characteristic of language-contact situations, pragmatic contextual factors such as the scant use of adverbial support, and, especially, diffusion from the input language, which is an earlier variety of spoken, non-standard English. Relevant intravarietal differences are also discussed and attributed to the different phases of development in which the four varieties currently find themselves.
The endonormative standards of European English
Authors: van den Doel Rias , Quené Hugo
Published: February 2013

It has been asserted that a common European variety of English is currently emerging. This so-called “European English” is claimed to be the result of convergence among non-native English speakers, and to reflect a gradual abandonment of Inner Circle norms, which are deemed to be increasingly irrelevant to non-native speakers’ communicative needs. Evidence is so far lacking that Europeans judge each other’s proficiency in English by anything other than native-speaker standards — particularly as regards pronunciation. Nonetheless, it would be interesting to establish whether European non-native speakers of English demonstrated convergence when evaluating the pronunciation of fellow Europeans, and in this respect deviated significantly not only from Inner Circle English native speakers but also from non-European judges. To investigate this possibility, a large-scale Internet survey was carried out in which different groups of users of English (native and non-native, European and non-European, N = 373) evaluated the pronunciation features of five European accents of English, by means of global ratings and detailed responses. The observed convergence of native and non-native judges’ responses does not correspond with emerging endonormative pronunciation standards on the European continent. Hence these findings fail to support the claims about an emerging European English variety.
Utility of a Clinical Risk Factor Scoring Model in Predicting Infection with Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae on Hospital Admission
Authors: Johnson Steven W. , Anderson Deverick J. , May D. Byron , Drew Richard H.
Published: February 2013

Objective.

To validate the utility of a previously published scoring model (Italian) to identify patients infected with community-onset extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-EKP) and develop a new model (Duke) based on local epidemiology.

Methods.

This case-control study included patients 18 years of age or more admitted to Duke University Hospital between January 1, 2008, and December 31, 2010, with culture-confirmed infection due to an ESBL-EKP (cases). Uninfected controls were matched to cases (3 : 1). The Italian model was applied to our patient population for validation. The Duke model was developed through logistic-regression-based prediction scores calculated on variables independently associated with ESBL-EKP isolation. Sensitivities and specificities at various point cutoffs were determined, and determination of the area under the receiver operating characteristic curve (ROC AUC) was performed.

Results.

A total of 123 cases and 375 controls were identified. Adjusted odds ratios and 95% confidence intervals for variables previously identified in the Italian model were as follows: hospitalization (3.20 [1.62–6.55]), transfer (4.31 [2.15–8.78]), urinary catheterization (5.92 [3.09–11.60]), β-lactam and/or fluoroquinolone therapy (3.76 [2.06–6.95]), age 70 years or more (1.55 [0.79–3.01]), and Charlson Comorbidity Score of 4 or above (1.06 [0.55–2.01]). Sensitivity and specificity were, respectively, more than or equal to 95% and less than or equal to 47% for scores 3 or below and were less than or equal to 50% and more than or equal to 96% for scores 8 or above. The ROC AUC was 0.88. Variables identified in the Duke model were as follows: hospitalization (2.63 [1.32–5.41]), transfer (5.30 [2.67–10.71]), urinary catheterization (6.89 [3.62–13.38]), β-lactam and/or fluoroquinolone therapy (3.47 [1.91–6.41]), and immunosuppression (2.34 [1.14–4.80]). Sensitivity and specificity were, respectively, more than or equal to 94% and less than or equal to 65% for scores 3 or below and were less than or equal to 58% and more than or equal to 95% for scores 8 or above. The ROC AUC was 0.89.

Conclusion.

While the previously reported model was an excellent predictor of community-onset ESBL-EKP infection, models utilizing factors based on local epidemiology may be associated with improved performance.
Proof of a folklore Julia set connectedness theorem and connections with elliptic functions
Authors: Hawkins Jane
Published: February 2013

We prove the following theorem about Julia sets of the maps
\[

f

n
,
p
,
γ

(
z
)
=

z
n

+

γ

z
p

,

f_{n,p,\gamma }(z)= z^n + \frac {\gamma }{z^p},

\]
for integers

n
,
p
≥
2

n,p \geq 2

,

γ
∈

C

\gamma \in \mathbb {C}

by using techniques developed for the Weierstrass elliptic

℘
\wp

function and adapted to this setting.

Folklore connectedness theorem: If

f

n
,
p
,
γ

f_{n,p,\gamma }

has a bounded critical orbit, then

J
(

f

n
,
p
,
γ

)

J(f_{n,p,\gamma })

is connected.

This is related to connectivity results by the author and others about

J
(
℘
)

J(\wp )

, where

℘
\wp

denotes the Weierstrass elliptic

℘
\wp

function, especially where the period lattice has some symmetry. We illustrate several further connections between the dynamics of some specific elliptic functions and the family

f

n
,
p
,
γ

f_{n,p,\gamma }

for some values of

n
n

and

p
p

.
Measurement of Total Dietary Fiber Using AOAC Method 2009.01 (AACC International Approved Method 32‐45.01): Evaluation and Updates
Authors: McCleary Barry V. , Sloane Naomi , Draga Anna , Lazewska Ida
Published: February 2013

The Codex Committee on Methods of Analysis and Sampling recently recommended 14 methods for measurement of dietary fiber, eight of these being type I methods. Of these type I methods, AACC International Approved Method 32‐45.01 (AOAC method 2009.01) is the only procedure that measures all of the dietary fiber components as defined by Codex Alimentarius. Other methods such as the Prosky method (AACCI Approved Method 32‐05.01) give similar analytical data for the high‐molecular‐weight dietary fiber contents of food and vegetable products low in resistant starch. In the current work, AACCI Approved Method 32‐45.01 has been modified to allow accurate measurement of samples high in particular fructooligosaccharides: for example, fructotriose, which, in the HPLC system used, chromatographs at the same point as disaccharides, meaning that it is currently not included in the measurement. Incubation of the resistant oligosaccharides fraction with sucrase/β‐galactosidase removes disaccharides that interfere with the quantitation of this fraction. The dietary fiber value for resistant starch type 4 (RS4), varies significantly with different analytical methods, with much lower values being obtained with AACCI Approved Method 32‐45.01 than with 32‐05.01. This difference results from the greater susceptibility of RS4 to hydrolysis by pancreatic α‐amylase than by bacterial α‐amylase, and also a greater susceptibility to hydrolysis at lower temperatures. On hydrolysis of samples high in starch in the assay format of AACCI Approved Method 32‐45.01 (AOAC method 2009.01), resistant maltodextrins are produced. The major component is a heptasaccharide that is highly resistant to hydrolysis by most of the starch‐degrading enzymes studied. However, it is hydrolyzed by the maltase/ amyloglucosidase/isomaltase enzyme complex present in the brush border lining of the small intestine. As a consequence, AOAC methods 2009.01 and 2011.25 (AACCI Approved Methods 32‐45.01 and 32‐50.01, respectively) must be updated to include an additional incubation with amyloglucosidase to remove these oligosaccharides.
Development and Psychometric Evaluation of a Postoperative Quality of Recovery Score
Authors: Stark Peter A. , Myles Paul S. , Burke Justin A.
Published: February 2013

Background:

Quality of recovery (QoR) after anesthesia is an important measure of the early postoperative health status of patients. The aim was to develop a short-form postoperative QoR score, and test its validity, reliability, responsiveness, and clinical acceptability and feasibility.

Methods:

Based on extensive clinical and research experience with the 40-item QoR-40, the strongest psychometrically performing items from each of the five dimensions of the QoR-40 were selected to create a short-form version, the QoR-15. This was then evaluated in 127 adult patients after general anesthesia and surgery.

Results:

There was good convergent validity between the QoR-15 and a global QoR visual analog scale (r = 0.68, P < 0.0005). Construct validity was supported by a negative correlation with duration of surgery (r = −0.49, P < 0.0005), time spent in the postanesthesia care unit (r = −0.41, P < 0.0005), and duration of hospital stay (r = −0.53, P < 0.0005). There was also excellent internal consistency (0.85), split-half reliability (0.78), and test–retest reliability (r

i
= 0.99), all P < 0.0005. Responsiveness was excellent with an effect size of 1.35 and a standardized response mean of 1.04. The mean ± SD time to complete the QoR-15 was 2.4 ± 0.8min.

Conclusions:

The QoR-15 provides a valid, extensive, and yet efficient evaluation of postoperative QoR.
Congenital Portosystemic Shunt
Authors: Sokollik Christiane , Bandsma Robert H.J. , Gana Juan C. , van den Heuvel Meta , Ling Simon C.
Published: February 2013

Objectives:

Congenital portosystemic shunts (CPSSs) are rare but increasingly recognized as a cause of important multisystem morbidity. We present new cases and a systematic literature review and propose an algorithm for the identification and care of affected patients.

Methods:

We reviewed the charts of consecutive patients seen in our pediatric liver clinic between 2003 and 2010 and systematically reviewed the literature of cases with CPSS.

Results:

We identified 316 published cases and 12 patients in our own clinic. Of the published cases (177 male), 185 had an extrahepatic and 131 an intrahepatic portosystemic shunt. Diagnosis was made at any age, from prenatal to late adulthood. Cardiac anomalies were found in 22% of patients. The main complications were hyperammonemia/neurological abnormalities (35%), liver tumors (26%), and pulmonary hypertension or hepatopulmonary syndrome (18%). The spectrum of neurological involvement ranged from changes in brain imaging, subtle abnormalities on neuropsychological testing, through learning disabilities to overt encephalopathy. Spontaneous shunt closure occurred mainly in infants with intrahepatic shunts. Therapeutic interventions included shunt closure by surgery or interventional radiology techniques (35%) and liver transplantation (10%) leading to an improvement of symptoms in the majority. These findings mirror the observations in our own patients.

Conclusions:

In this largest review of the reported clinical experience, we identify that children with CPSS may present with otherwise unexplained developmental delay, encephalopathy, pulmonary hypertension, hypoxemia, or liver tumors. When CPSS is diagnosed, children should be screened for all of these complications. Spontaneous closure of intrahepatic shunts may occur in infancy. Closure of the shunt is indicated in symptomatic patients and is associated with a favorable outcome.
A family of diatom-like silicon transporters in the siliceous loricate choanoflagellates
Authors: Marron Alan O. , Alston Mark J. , Heavens Darren , Akam Michael , Caccamo Mario , Holland Peter W. H. , Walker Giselle
Published: February 2013

Biosilicification is widespread across the eukaryotes and requires concentration of silicon in intracellular vesicles. Knowledge of the molecular mechanisms underlying this process remains limited, with unrelated silicon-transporting proteins found in the eukaryotic clades previously studied. Here, we report the identification of silicon transporter (SIT)-type genes from the siliceous loricate choanoflagellates
Stephanoeca diplocostata
and
Diaphanoeca grandis
. Until now, the SIT gene family has been identified only in diatoms and other siliceous stramenopiles, which are distantly related to choanoflagellates among the eukaryotes. This is the first evidence of similarity between SITs from different eukaryotic supergroups. Phylogenetic analysis indicates that choanoflagellate and stramenopile SITs form distinct monophyletic groups. The absence of putative SIT genes in any other eukaryotic groups, including non-siliceous choanoflagellates, leads us to propose that SIT genes underwent a lateral gene transfer event between stramenopiles and loricate choanoflagellates. We suggest that the incorporation of a foreign SIT gene into the stramenopile or choanoflagellate genome resulted in a major metabolic change: the acquisition of biomineralized silica structures. This hypothesis implies that biosilicification has evolved multiple times independently in the eukaryotes, and paves the way for a better understanding of the biochemical basis of silicon transport through identification of conserved sequence motifs.
Distinct neural and neuromuscular strategies underlie independent evolution of simplified advertisement calls
Authors: Leininger Elizabeth C. , Kelley Darcy B.
Published: February 2013

Independent or convergent evolution can underlie phenotypic similarity of derived behavioural characters. Determining the underlying neural and neuromuscular mechanisms sheds light on how these characters arose. One example of evolutionarily derived characters is a temporally simple advertisement call of male African clawed frogs (Xenopus) that arose at least twice independently from a more complex ancestral pattern. How did simplification occur in the vocal circuit? To distinguish shared from divergent mechanisms, we examined activity from the calling brain and vocal organ (larynx) in two species that independently evolved simplified calls. We find that each species uses distinct neural and neuromuscular strategies to produce the simplified calls. Isolated Xenopus borealisbrains produce fictive vocal patterns that match temporal patterns of actual male calls; the larynx converts nerve activity faithfully into muscle contractions and single clicks. In contrast, fictive patterns from isolatedXenopus boumbaensisbrains are short bursts of nerve activity; the isolated larynx requires stimulus bursts to produce a single click of sound. Thus, unlikeX. borealis, the output of theX. boumbaensishindbrain vocal pattern generator is an ancestral burst-type pattern, transformed by the larynx into single clicks. Temporally simple advertisement calls in genetically distant species ofXenopushave thus arisen independently via reconfigurations of central and peripheral vocal neuroeffectors.
Accurate decisions in an uncertain world: collective cognition increases true positives while decreasing false positives
Authors: Wolf Max , Kurvers Ralf H. J. M. , Ward Ashley J. W. , Krause Stefan , Krause Jens
Published: February 2013

In a wide range of contexts, including predator avoidance, medical decision-making and security screening, decision accuracy is fundamentally constrained by the trade-off between true and false positives. Increased true positives are possible only at the cost of increased false positives; conversely, decreased false positives are associated with decreased true positives. We use an integrated theoretical and experimental approach to show that a group of decision-makers can overcome this basic limitation. Using a mathematical model, we show that a simple quorum decision rule enables individuals in groups to simultaneously increase true positives and decrease false positives. The results from a predator-detection experiment that we performed with humans are in line with these predictions: (i) after observing the choices of the other group members, individuals both increase true positives and decrease false positives, (ii) this effect gets stronger as group size increases, (iii) individuals use a quorum threshold set between the average true- and false-positive rates of the other group members, and (iv) individuals adjust their quorum adaptively to the performance of the group. Our results have broad implications for our understanding of the ecology and evolution of group-living animals and lend themselves for applications in the human domain such as the design of improved screening methods in medical, forensic, security and business applications.
Artificial light at night advances avian reproductive physiology
Authors: Dominoni Davide , Quetting Michael , Partecke Jesko
Published: February 2013

Artificial light at night is a rapidly increasing phenomenon and it is presumed to have global implications. Light at night has been associated with health problems in humans as a consequence of altered biological rhythms. Effects on wild animals have been less investigated, but light at night has often been assumed to affect seasonal cycles of urban dwellers. Using light loggers attached to free-living European blackbirds (
Turdus merula
), we first measured light intensity at night which forest and city birds are subjected to in the wild. Then we used these measurements to test for the effect of light at night on timing of reproductive physiology. Captive city and forest blackbirds were exposed to either dark nights or very low light intensities at night (0.3 lux). Birds exposed to light at night developed their reproductive system up to one month earlier, and also moulted earlier, than birds kept under dark nights. Furthermore, city birds responded differently than forest individuals to the light at night treatment, suggesting that urbanization can alter the physiological phenotype of songbirds. Our results emphasize the impact of human-induced lighting on the ecology of millions of animals living in cities and call for an understanding of the fitness consequences of light pollution.