bluuebunny/crossref_metadata_2025 huggingface dataset:
Three‐Dimensional Quantile Plots and Dynamic Quantile Plots of the Prediction Variance for Response Surface Designs
Authors: Jang Dae‐Heung , Anderson‐Cook Christine M. , Kim Youngil
Published: October 2011

A historically common choice for evaluating response surface designs is to use alphabetic optimality criteria. Single‐number criteria such as D, A, G, and V optimality do not completely reflect the estimation or prediction variance characteristics of the designs in question. For prediction‐based assessment, alternatives to single‐number summaries include the graphical displays of the prediction variance across the design regions. Variance dispersion graphs, fraction of design space plots, and quantile plots have been suggested to evaluate the overall prediction capability of response surface designs. The quantile plots use the percentiles. These quantile plots use the percentiles of the distribution at a given radius instead of just the mean, maximum, and minimum prediction variance values on concentric spheres inside the region of the interest. Previously, the user had to select several values of radius and draw corresponding quantile plots to evaluate the overall prediction capability of response surface designs. The user‐specified choice of radii to examine makes the plot somewhat subjective. Alternately, we propose to remove this subjectivity by using a three‐dimensional quantile plot. As another extension of the quantile plots, we suggest dynamic quantile plots to animate the quantile plots and use them for comparing and evaluating response surface designs. Copyright © 2011 John Wiley & Sons, Ltd.
Design, Assembly, and Activity of Antisense DNA Nanostructures
Authors: Keum Jung‐Won , Ahn Jin‐Ho , Bermudez Harry
Published: October 2011

Discrete DNA nanostructures allow simultaneous features not possible with traditional DNA forms: encapsulation of cargo, display of multiple ligands, and resistance to enzymatic digestion. These properties suggested using DNA nanostructures as a delivery platform. Here, DNA pyramids displaying antisense motifs are shown to be able to specifically degrade mRNA and inhibit protein expression in vitro, and they show improved cell uptake and gene silencing when compared to linear DNA. Furthermore, the activity of these pyramids can be regulated by the introduction of an appropriate complementary strand. These results highlight the versatility of DNA nanostructures as functional devices.
Improving Resilience of Critical Human Systems in CBRN Emergencies: Challenges for First Responders
Authors: Chroust Gerhard , Rainer Karin , Sturm Nadine , Roth Markus , Ziehesberger Peter
Published: October 2011

Today's catastrophes (many of them man‐made or at least triggered by human activities) frequently endanger a growing number of humans and larger areas in numerous different ways, calling for more attention concerning dependability and resilience of our environment. Experience tells us that no matter what precautions and quality approaches we take, we will always encounter systems that initially were dependable and ‘suddenly’ become untrustworthy because of some unexpected, unknown cause. A system that in itself is unable to re‐establish its dependability, that is, is not resilient (any more), needs an external intervention: For human beings, a physician acts as an intervening system for re‐establishing dependability. A complex system can be made resilient by the addition of an Intervention System that intervenes in the case of loss of dependability. In this paper, we investigate the role of First Responders (i.e. fire brigade, ambulance services and police forces) as intervening systems in the case of CBRN (chemical, biological, radiological, or nuclear) incidents, aimed at providing resilience. Taking a process view of these interventions, we analyse key processes especially with respect to supporting them by Information and Communication Technologies (ICT). We identify properties of CBRN incidents and their implications for the activities of First Responders both in training and real assignments. The paper is based on the following study: Chroust et al. “Improving resilience of critical human systems in CBRN‐emergencies: challenges for first responders”. Copyright © 2011 John Wiley & Sons, Ltd.
From Building Environmental Representations to Structural Coupling—an Autopoietic Theory Perspective on the Theory and Practice of Strategic Management
Authors: Brocklesby John
Published: October 2011

This paper seeks to extend the usefulness of autopoietic theory within organization studies by tying it to a renewal of interest in that field in real‐world activities, micro‐level practices and process thinking more generally. Focusing specifically on strategic management, the paper attempts to demonstrate how autopoietic theory's distinctive perspective on cognition and structural coupling can provide more convincing accounts of this area of practice than is possible using conventional understandings. Using the dominant ‘cognitivist’ approach as a starting point and using illustrative material taken from a major research project that has examined the strategic management process in exemplar firms, the paper questions the idea that strategic activities and outcomes reflect the intent, decisions and interventions of managers to accommodate, respond to and/or exploit external circumstances. The paper has argued that more convincing accounts are possible using the autopoietic theory's more process‐based, co‐evolutionary and self‐organizing perspective. Copyright © 2011 John Wiley & Sons, Ltd.
Embracing Human Experience in Applied Systems‐Thinking
Authors: Córdoba‐Pachón José‐Rodrigo
Published: October 2011

Applied systems‐thinking involves the use of systems methodologies and concepts to facilitate intervention in social situations. In this area, a body of knowledge has been accumulated to promote informed use of systems methodology. Still, how human experience is considered and used in intervention is limited to what methodologies prescribe or what facilitators do with it. In this paper, we revisit the ideas of autopoiesis and in particular the research project pursued by one of his original authors (Francisco Varela). Following Varela's intent to develop a middle way in science, we reflect on how applied systems‐thinkingcould take a step back regarding how human experience is integrated into intervention. We conclude the paper with a number of suggestions to make applied systems‐thinking more permeable and sensitive to human experience and therefore open to compassionate thinking and action. Copyright © 2011 John Wiley & Sons, Ltd.
Towards a Framework for Multiparadigm Multimethodologies
Authors: Bowers Todd D.
Published: October 2011

The multimethodological practice of systemic intervention has been described as ‘theoretically contradictory eclecticism’ because it lacks a grounding theory that can accept Burrell and Morgan's principle of incommensurable paradigms and avoids ‘anything goes’ relativism between them. As a way forward, a new ontology of process–structure is proposed. It is designed as a metaphysical interface to the onto‐epistemological paradigms of critical systems thinking and practice (which are, in this paper, functionalist–structuralist, interpretivist, critical–emancipatory and postmodern–poststructuralist). Next, the ontology is realized by an epistemology that respects paradigm incommensurability and yet exploits the unique perspective they each afford. Then, a methodology wherein each of the paradigmatic approaches is critically deployed operationalizes and completes the foundation of this new framework. It directs a critically reflexive, axiologically transparent appreciation by the systemist in a multiparadigmatic, multimethodological engagement with the ‘problem’ situation in flux. The philosophy lays out foundational motives, rationale, intents and purposes and acts as a guide for its use in practice. Copyright © 2011 John Wiley & Sons, Ltd.
Concise Review: The Promise of Human Induced Pluripotent Stem Cell-Based Studies of Schizophrenia
Authors: Brennand Kristen J. , Gage Fred H.
Published: October 2011

Schizophrenia (SCZD) is a heritable developmental disorder. Although the molecular mechanism of disease remains unclear, insights into the disorder have been made through a vast array of experimental techniques. Together, magnetic resonance brain imaging, pharmacological, and post-mortem pathological studies have observed decreased brain volume, aberrant neurotransmitter signaling, reduced dendritic arborization, and impaired myelination in SCZD. Genome-wide association studies (GWAS) have identified common single nucleotide polymorphisms as well as rare copy number variants that contribute to SCZD, while mouse models of candidate SCZD genes show behavioral abnormalities and anatomical perturbations consistent with human disease. The advent of human induced pluripotent stem cells (hiPSCs) makes it possible to study SCZD using live human neurons with a genetic predisposition toward SCZD, even without knowledge of the genes interacting to produce the disease state. SCZD hiPSC neurons show cellular defects comparable to those identified in post-mortem human and mouse studies, and gene expression changes are consistent with predictions made by GWAS. SCZD hiPSC neurons represent a new tool to look beyond phenotype and begin to dissect the molecular mechanisms of SCZD.
The Classroom Environment
Authors: Roskos Kathleen , Neuman Susan B.
Published: October 2011

The classroom environment is uppermost in teachers' minds at the start of each school year. Designing an effective classroom environment for learning to read and reading is both an art and a science. Aligning physical space with instructional goals involves the flexible use of space that is adapted to instructional needs. A well‐designed classroom environment is the first step in providing a literate environment that fosters reading and writing to learn.
Comparison of turbulence models for the computational fluid dynamics simulation of wind turbine wakes in the atmospheric boundary layer
Authors: Cabezón D. , Migoya E. , Crespo A.
Published: October 2011

An elliptic computational fluid dynamics wake model based on the actuator disk concept is used to simulate a wind turbine, approximated by a disk upon which a distribution of forces, defined as axial momentum sources, is applied on an incoming non‐uniform shear flow. The rotor is supposed to be uniformly loaded with the exerted forces estimated as a function of the incident wind speed, thrust coefficient and rotor diameter. The model is assessed in terms of wind speed deficit and added turbulence intensity for different turbulence models and is validated from experimental measurements of the Sexbierum wind turbine experiment.

The elliptic model is also compared with other wake models in the literature on the basis of parabolic and large eddy simulation approximations. Copyright © 2011 John Wiley & Sons, Ltd.
Phototransduction mechanisms in Drosophila microvillar photoreceptors
Authors: Hardie Roger C.
Published: October 2011

Phototransduction in Drosophila is mediated by a G‐protein coupled phospholipase C (PLC) cascade leading to graded membrane depolarization. It is the preferred model for phototransduction in microvillar photoreceptors and an important model for the ubiquitous phosphoinositide signaling cascade. The photoreceptors respond sensitively to single photons 10–100× more rapidly than vertebrate rods, yet still light adapt to signal under full sunlight. Incident light is absorbed and transduced in the rhabdomere, a 1–2 µm diameter, 100 µm long waveguide composed of ∼30,000 tightly packed microvilli, which contain the visual pigment rhodopsin and all the major components of the cascade. PLC hydrolyzes phosphatidyl‐inositol (4,5) bisphosphate (PIP2) to generate diacylglycerol (DAG), inositol (1,4,5) trisphosphate (InsP3), and also a proton. This results in activation of two classes of Ca2+ permeable cation channels, TRP and TRPL—the prototypical members of the transient receptor potential (TRP) superfamily of cation channels. Recent evidence suggests that the channels may be activated in a combinatorial manner by two neglected consequences of PLC activity, namely simultaneous depletion of PIP2 and acidification. Several components of the cascade, including TRP, PLC, and protein kinase C are assembled into multimolecular signaling complexes by the PDZ‐domain scaffolding protein INAD. Ca2+ influx via TRP channels is essential for rapid kinetics, amplification, and light adaptation and mediates both positive and negative feedback via multiple downstream targets, including the channels, rhodopsin, and PLC. This Ca2+‐dependent feedback along with the ultracompartmentalization provided by the microvillar design and molecular scaffolding is critical for the combination of sensitivity, rapid kinetics, and broad dynamic range. WIREs Membr Transp Signal 2012, 1:162–187. doi: 10.1002/wmts.20

For further resources related to this article, please visit the WIREs website.
Expanded learning time and opportunities: Key principles, driving perspectives, and major challenges
Authors: Blyth Dale A. , LaCroix‐Dalluhn Laura
Published: October 2011

If expanded learning is going to make a real difference, then three key principles must inform how communities overcome challenges and assure equitable access to learning opportunities.
From after‐school to expanded learning: A decade of progress
Authors: Stonehill Robert M. , Lauver Sherri C. , Donahue Tara , Naftzger Neil , McElvain Carol K. , Stephanidis Jaime
Published: October 2011

Following a decade of rapid expansion of afterschool enrichment programs, leaders in the field are rethinking how those programs can be designed to play a larger role in supporting student achievement and development and in strengthening school reform initiatives.
School dropout prevention: What arts‐based community and out‐of‐school‐time programs can contribute
Authors: Charmaraman Linda , Hall Georgia
Published: October 2011

Out‐of‐school‐time programs, especially arts‐based programs, can be critical players in a community's efforts to prevent school dropout. This research review suggests the following approaches for arts‐based programs: (1) recruitment and retention of target populations with multiple risk factors; (2) long‐term skill development that engages youth behaviorally, emotionally, and academically rather than a drop‐in culture; (3) an emphasis on the critical ingredient of real‐world applications through performance; (4) staff development and mentoring; (5) a strategic community‐level plan for dropout prevention; (6) and program content reframed toward competencies that underlie better school performance and prosocial behavior, such as communication, initiative, problem solving, motivation, and self‐efficacy.
Possible involvement of GDI1 protein, a GDP dissociation inhibitor related to vesicle transport, in an amelioration of zinc toxicity in Saccharomyces cerevisiae
Authors: Ezaki Bunichi , Nakakihara Eri
Published: October 2011

The GDI1 protein related vesicle transport system was studied to investigate the possibility that an exclusion of toxic zinc (Zn) from the cytoplasm ameliorates Zn toxicity in Saccharomyces cerevisiae (yeast). A temperature‐sensitive gdi1 mutant (originally called sec19), in which the GDP dissociation inhibitor becomes inactive at the non‐permissive temperature (37 °C), was more sensitive to Zn than its parental GDI1 strain at 32 °C (a moderately non‐permissive temperature). The relative efflux of cytoplasmic Zn in the gdi1 mutant was lower than that in the control strain. Treatment with a vesicle transport‐specific inhibitor, Brefeldin A, caused an increase of Zn sensitivity and a decrease of Zn efflux in these strains. It is therefore suggested that the GDI1‐related vesicle transport system contributes to Zn tolerance in yeast. Furthermore, changes in the number of Zn‐specific fluorescent granules (zincosomes) were observed by zinquin staining in the mutant cells under Zn treatment at 32 °C and 37 °C. We concluded that the GDI1 protein is implicated in control of vesicle numbers. Collectively, the results suggest that the GDI1protein is involved in Zn efflux via small vesicle trafficking and contributes to the control of cytoplasmic Zn content, allowing yeast to survive in the presence of toxic Zn. Copyright © 2011 John Wiley & Sons, Ltd.
Homoleptic Octahedral Methylamine Complexes of Manganese(II): Solvothermal Syntheses and Crystal Structures of [Mn(NH2CH3)6]Cl2 and the Pentaselenide [Mn(NH2CH3)6]Se5
Authors: Kysliak Oleksandr , Daniels Jörg , Schnakenburg Gregor , Beck Johannes
Published: October 2011

[Mn(NH2CH3)6]Cl2 (1) and [Mn(NH2CH3)6]Se5 (2) were prepared by solvothermal reactions in liquid methylamine from MnCl2 at 150 °C for 1 and from a mixture of MnCl2, Rb2Se and selenium at 120 °C for 2. Both 1 and 2 were obtained in high yields as colorless and dark‐red crystals and represent the first homoleptic methylamine complexes with coordination number six. Compound 1 crystallizes rhombohedral (R$\bar{3}$, Z = 3) and is built of only slightly distorted octahedral [Mn(NH2CH3)6]2+ cations and Cl– anions. Compound 2 crystallizes orthorhombic (Pnna, Z = 4) and is built of octahedral [Mn(NH2CH3)6]2+ cations showing a strong angular distortion and of Se52– anions in the form of chains in transoid conformation. DFT calculations reveal an almost undistorted ground state structure for [Mn(NH2CH3)6]2+ with N–Mn–N angular distortions of 1° from orthogonality, close to the structure found for the complex in 1. The calculated energy necessary for a distortion as found in the structure of 2 is rather low and amounts to 26 kJmol–1 which is in the range typical for hydrogen bonds. The N–Mn–N angular distortions of the complex cation in 2, observed in the range of 10°, is caused by cation‐anion interactions in the crystal structure by N–H····Se hydrogen bonds.
Mediators of change in cognitive behaviour therapy and mebeverine for irritable bowel syndrome
Authors: Reme S. E. , Stahl D. , Kennedy T. , Jones R. , Darnley S. , Chalder T.
Published: October 2011

Background

Cognitive behaviour therapies (CBTs) have through several trials been demonstrated to reduce symptoms and disability in irritable bowel syndrome (IBS) patients, but the mechanisms responsible for the changes are still unknown. The aim of this study was to test a theoretical model of CBT and investigate if cognitions and/or behaviour mediated the changes seen in CBT for IBS.

Method

To assess for possible mediating effects, we applied path analysis to the dataset of 149 diagnosed participants randomized to mebeverine hydrochloride plus CBT or mebeverine hydrochloride alone. Primary outcome was symptom severity, while secondary outcomes were work and social adjustment and anxiety.

Results

The path analyses supported mediational paths for all outcomes. Changes in behaviour and cognitions mediated all three outcomes, with models placing behaviour change ‘upstream’ of cognition change having best fit. The analyses of model fits revealed best fit for the anxiety model and hence provide increased confidence in the causal model of anxiety.

Conclusions

Changes in behaviour and cognitions mediate the change in CBT given to IBS patients. The results strengthen the validity of a theoretical model of CBT by confirming the interaction of cognitive, emotional and behavioural factors in IBS.
Management of Antarctic baleen whales amid past exploitation, current threats and complex marine ecosystems
Authors: Leaper Rebecca , Miller Cara
Published: October 2011

As baleen whales recover from severe exploitation, they are probably subject to a wide variety of threats within the Antarctic marine ecosystem, including directed take. Here we review both the management and current status of Antarctic baleen whales and consider those threats likely to impact on them. Threats range from global problems - marine pollution and climate change - to localized issues including shipping, habitat disturbance, unregulated wildlife tourism and fishery activities. We identify the most pressing anthropogenic threats to baleen whales including scientific whaling and climate change. It is unclear whether current management approaches will be able to effectively encompass all these threats while also accounting both for the differing levels of scientific understanding and for the differing recovery rates of the whale species. For management we recommend the following: 1) incorporation of both ecosystem considerations and the suite of identified threats not limited to direct take, 2) identification of measurable indicators of changes in whales that allow more certainty in monitoring of populations and the environment, and 3) recognition of significant relationships between baleen whales and habitat features to provide information on distribution and use.
Nuclear War in the Middle East: Where is the Voice of Medicine and Public Health?
Authors: Dallas Cham E. , Burkle Frederick M.
Published: October 2011

Once again, the politically volatile Middle East and accompanying rhetoric has escalated the risk of a major nuclear exchange. Diplomatic efforts have failed to make the medical consequences of such an exchange a leading element in negotiations. The medical and academic communities share this denial. Without exaggeration, the harsh reality of the enormous consequences of an imminently conceivable nuclear war between Iran and Israel will encompass an unprecedented millions of dead and an unavoidable decline in public health and environmental devastation that would impact major populations in the Middle East for decades to come. Nuclear deterrence and the uncomfortable but real medical and public health consequences must become an integral part of a broader global health diplomacy that emphasizes health security along with poverty reduction and good governance.
O2 reduction and denitrification rates in shallow aquifers
Authors: Tesoriero Anthony J. , Puckett Larry J.
Published: October 2011

O2 reduction and denitrification rates were determined in shallow aquifers of 12 study areas representing a wide range in sedimentary environments and climatic conditions. Zero‐ and first‐order rates were determined by relating reactant or product concentrations to apparent groundwater age. O2 reduction rates varied widely within and between sites, with zero‐order rates ranging from <3 μmol L−1 yr−1 to more than 140 μmol L−1 yr−1 and first‐order rates ranging from 0.02 to 0.27 yr−1. Moderate denitrification rates (10–100 μmol N L−1 yr−1; 0.06–0.30 yr−1) were observed in most areas with O2 concentrations below 60 μmol L−1, while higher rates (>100 μmol N L−1 yr−1; >0.36 yr−1) occur when changes in lithology result in a sharp increase in the supply of electron donors. Denitrification lag times (i.e., groundwater travel times prior to the onset of denitrification) ranged from <20 yr to >80 yr. The availability of electron donors is indicated as the primary factor affecting O2 reduction rates. Concentrations of dissolved organic carbon (DOC) and/or sulfate (an indicator of sulfide oxidation) were positively correlated with groundwater age at sites with high O2 reduction rates and negatively correlated at sites with lower rates. Furthermore, electron donors from recharging DOC are not sufficient to account for appreciable O2 and nitrate reduction. These relations suggest that lithologic sources of DOC and sulfides are important sources of electrons at these sites but surface‐derived sources of DOC are not. A review of published rates suggests that denitrification tends to occur more quickly when linked with sulfide oxidation than with carbon oxidation.
The effects of excited state lifetime, optical intensity, and excited state quenchers on the photostability of zwitterionic chromophores
Authors: Williams G. V. M. , Kutuvantavida Y. , Janssens S. , Raymond S. G. , Do My T. T. , Bhuiyan M. D. H. , Quilty J. W. , Denton N. , Kay A. J.
Published: October 2011

Photoluminescence (PL) and photostability measurements have been made on thin films containing the 2nd order nonlinear optic chromophore, PYR-3, and amorphous polycarbonate (APC). We find that the PYR-3 singlet excited state PL lifetime systematically decreases with increasing PYR-3 concentration, which may be due to PYR-3 excited state energy transfer to non-radiative decay sites. There is no correlation between the PL lifetime and the photostability for low optical intensities, and we find that the photobleaching data cannot be modeled with a single photodegradation quantum efficiency. There is an increase in the photostability with increasing optical intensity, and this enhancement is larger for high PYR-3 concentrations. It can be explained by a reduction in the oxygen content by oxygen-mediated photodegradation for the 5% PYR-3/APC films. This also partly explains the enhancement in the 15% PYR-3/APC films, but there is an additional mechanism as well. The photostability can also be improved by adding beta-carotene, which leads to an enhancement factor of greater than 6.
Efficient evanescent wave coupling conditions for waveguide-integrated thin-film Si/Ge photodetectors on silicon-on-insulator/germanium-on-insulator substrates
Authors: Ahn Donghwan , Kimerling Lionel C. , Michel Jurgen
Published: October 2011

We studied evanescent wave coupling behavior between low index-contrast upper-level waveguides and thin-film Si and Ge photodetectors on SOI and germanium-on-insulator (GOI) substrates, respectively. We present a simple and intuitive leaky-mode phase-matching model using a ray-optics approach to determine the conditions for efficient coupling, both in 2D and 3D structures. It is shown that the presence of leaky modes that are phase-matched between the waveguide and the Si or Ge photodetector layer is the key condition for efficient coupling. Our approach was compared to other methods, such as finite-difference time domain (FDTD)/beam propagation method (BPM) and mode analysis. We report that, depending on the way a waveguide photodetector device is designed, waveguide-to-photodetector coupling efficiency may or may not be critically sensitive to design parameters, such as the photodetector layer thickness. As an example, the stark contrast of coupling behavior in the two most popular Ge photodetector structures integrated with Si rib waveguide versus channel waveguide is shown. The device design factors and the trends that affect such coupling sensitivity are identified and explained in the paper.
Energy level decay and excited state absorption processes in erbium-doped tellurite glass
Authors: Gomes Laércio , Oermann Michael , Ebendorff-Heidepriem Heike , Ottaway David , Monro Tanya , Felipe Henriques Librantz André , Jackson Stuart D.
Published: October 2011

The fundamental excited state decay processes relating to the 4I11/2 → 4I13/2 transition in singly Er3+-doped tellurite (TZNL) glass have been investigated in detail using time-resolved fluorescence spectroscopy. Selective laser excitation of the 4I11/2 energy level at 970 nm and selective laser excitation of the 4I13/2 energy level at 1485 nm has established that energy transfer upconversion by way of a dipole-dipole interaction between two excited erbium ions in the 4I13/2 level populates the 4I11/2 upper laser level of the 3 μm transition. This upconversion has been analyzed for Er2O3 concentrations between 0.5 mol. % and 2.2 mol. %. The 4I13/2 and 4I11/2 energy levels emit luminescence with peaks located at 1532 nm and 2734 nm, respectively, with radiative decay efficiencies of 65% and 6.8% for the higher (2.2 mol. %) concentration sample. The low 2.7 μm emission efficiency is due to the non-radiative decay bridging the 4I11/2 → 4I13/2 transition and energy transfer to the OH− groups in the glass. Excited state absorption was observed to occur from the 4I13/2 and 4I11/2 levels with peak absorptions occurring at 1550 nm and 971 nm, respectively. The decay time of the 4I11/2 excited state decreased with an increase in the Er3+ concentration, which related to energy transfer to OH− ions that had a measured concentration of 6.6 × 1018 cm−3. Results from numerical simulations showed that a population inversion is reached at a threshold pumping intensity of ∼80 kW cm−2 for a cw laser pump at 976 nm if [Er3+] ≥ 1.2 × 1021 cm−3 (or [Er2O3] ≥ 2.65 mol. %) without OH− impurities being present.
Irradiance influence on the multicolor photochromism of mesoporous TiO2 films loaded with silver nanoparticles
Authors: Crespo-Monteiro N. , Destouches N. , Nadar L. , Reynaud S. , Vocanson F. , Michalon J. Y.
Published: October 2011

The photochromism of heterogeneous silver nanoparticles grown thermally in mesoporous TiO2 films is investigated under visible laser illuminations with different irradiances. At low irradiance, a selective oxidation occurs that changes the film color in accordance with the illuminant wavelength. At higher irradiance, the oxidation of large nanoparticles is going with the formation of many small nanoparticles in their vicinity, which gives the films an orangy color whatever the wavelength. This color fades after long exposure times at a laser line. The laser polarization has also an influence on the dichroism of the colored films.
Composition dependent-magnetocaloric effect and low room-temperature coefficient of resistivity study of iron-based antiperovskite compounds Sn1−xGaxCFe3 (0 ≤ x ≤ 1.0)
Authors: Lin S. , Wang B. S. , Lin J. C. , Zhang L. , Hu X. B. , Huang Y. N. , Lu W. J. , Zhao B. C. , Tong P. , Song W. H. , Sun Y. P.
Published: October 2011

We present the magnetic/structural phase diagram of Sn1-xGaxCFe3 (0 ≤ x ≤ 1). With increasing x, Curie temperature (TC) and saturated magnetization increase while lattice constant decreases. The results indicate that GaCFe3 may be a promising high-temperature soft magnetic material. Around TC, chemical composition-dependent magnetocaloric effect is studied. The relative cooling power increases with increasing x, reaching a maximum of ∼3.22 J/cm3 (∼61% of Gd) around 345 K. Considering their remarkable advantages, Sn1-xGaxCFe3 are suggested to be promising magnetic refrigerant materials. The low-T resistivity displays a metallic behavior for x ≤ 0.80 and a semiconductor-like behavior for GaCFe3. Furthermore, room-temperature coefficient of resistivity is comparative (∼46.2 ppm/K for GaCFe3, 250-310 K).
A magnetically driven piston pump for ultra-clean applications
Authors: LePort F. , Neilson R. , Barbeau P. S. , Barry K. , Bartoszek L. , Counts I. , Davis J. , deVoe R. , Dolinski M. J. , Gratta G. , Green M. , Díez M. Montero , Müller A. R. , O’Sullivan K. , Rivas A. , Twelker K. , Aharmim B. , Auger M. , Belov V. , Benitez-Medina C. , Breidenbach M. , Burenkov A. , Cleveland B. , Conley R. , Cook J. , Cook S. , Craddock W. , Daniels T. , Dixit M. , Dobi A. , Donato K. , Fairbank W. , Farine J. , Fierlinger P. , Franco D. , Giroux G. , Gornea R. , Graham K. , Green C. , Hägemann C. , Hall C. , Hall K. , Hallman D. , Hargrove C. , Herrin S. , Hughes M. , Hodgson J. , Juget F. , Kaufman L. J. , Karelin A. , Ku J. , Kuchenkov A. , Kumar K. , Leonard D. S. , Lutter G. , Mackay D. , MacLellan R. , Marino M. , Mong B. , Morgan P. , Odian A. , Piepke A. , Pocar A. , Prescott C. Y. , Pushkin K. , Rollin E. , Rowson P. C. , Schmoll B. , Sinclair D. , Skarpaas K. , Slutsky S. , Stekhanov V. , Strickland V. , Swift M. , Vuilleumier J.-L. , Vuilleumier J.-M. , Wichoski U. , Wodin J. , Yang L. , Yen Y.-R.
Published: October 2011

A magnetically driven piston pump for xenon gas recirculation is presented. The pump is designed to satisfy extreme purity and containment requirements, as is appropriate for the recirculation of isotopically enriched xenon through the purification system and large liquid xenon time projection chamber of EXO-200. The pump, using sprung polymer gaskets, is capable of pumping more than 16 standard liters per minute of xenon gas with 750 Torr differential pressure.
A theoretical study of hydrogen- and lithium-bonded complexes of F–H/Li and Cl–H/Li with NF3, NH3, and NH2(CH3)
Authors: McDowell Sean A. C. , Hill Janine A. S. St.
Published: October 2011

Hydrogen- and lithium-bonded complexes of A−H/Li (A = F, Cl) with the amine analogues NF3, NH3, and NH2(CH3) were studied at the MP2/6-311++G(d,p) level of theory. Bond extensions and redshifts were obtained for the H-bonded complexes, while bond extensions and blueshifts were obtained for the Li-bonded species. The variation of these and other properties with the basicity of the amines was investigated and rationalized by comparing the ab initio results with predictions from a model derived from perturbation theory.
A neural network circuit using persistent interfacial conducting heterostructures
Authors: Ueda Michihito , Kaneko Yukihiro , Nishitani Yu , Fujii Eiji
Published: October 2011

The FeFET, based on epitaxial perovskite heterostructures, is termed an OxiM. It showed persistent interfacial conduction even when the ferroelectric polarization curve was swinging on a minor loop and also showed good controllability of drain current using pulse voltages. A neuron circuit composed of OxiMs and an op-amp adder circuit showed that the gain of the neuron circuit could also be modulated smoothly by means of pulse voltages. Using a numerical model of the neuron circuit, we simulated the learning process for “exclusive OR” and achieved a good convergence characteristic.
InGaN metal-semiconductor-metal photodetectors with triethylgallium precursor and unactivated Mg-doped GaN cap layers
Authors: Lee K. H. , Chang P. C. , Chang S. J. , Wu S. L.
Published: October 2011

InGaN epitaxial films grown by metalorganic chemical vapor deposition using trimethylgallium and triethylgallium as precursors exhibited different optical and electrical properties. The films were characterized by x-ray diffraction, photoluminescence, secondary ion mass spectroscopy, and atomic force microscopy. Impacts of unactivated Mg-doped GaN in situ grown cap layers on InGaN and GaN films were further investigated. Current-voltage and spectral response measurements combined with Hall-effect measurement and analytical modeling have been used to assess possible current transport mechanisms of reverse dark and photo current flow in metal-semiconductor-metal photodetectors fabricated from InGaN and GaN. Unlike the dominant thermionic emission, which can be blocked by higher and thicker potential barrier in GaN, the trap-assisted tunneling is more pronounced in InGaN. The passivation effect on high density surface states in InGaN is proposed to explain the improved device performances after the incorporation of Mg-doped GaN.
Cryogenic ultra-low-noise SiGe transistor amplifier
Authors: Ivanov B. I. , Trgala M. , Grajcar M. , Il'ichev E. , Meyer H.-G.
Published: October 2011

An ultra-low-noise one-stage SiGe heterojunction bipolar transistor amplifier was designed for cryogenic temperatures and a frequency range of 10 kHz–100 MHz. A noise temperature TN ≈ 1.4 K was measured at an ambient temperature of 4.2 K at frequencies between 100 kHz and 100 MHz for a source resistance of ∼50 Ω. The voltage gain of the amplifier was 25 dB at a power consumption of 720 μW. The input voltage noise spectral density of the amplifier is about 35 pV/\documentclass[12pt]{minimal}\begin{document}$\sqrt{\rm Hz}$\end{document} Hz . The low noise resistance and power consumption makes the amplifier suitable for readout of resistively shunted DC SQUID magnetometers and amplifiers.
Surface transport of energetic electrons in intense picosecond laser-foil interactions
Authors: Gray R. J. , Yuan X. H. , Carroll D. C. , Brenner C. M. , Coury M. , Quinn M. N. , Tresca O. , Zielbauer B. , Aurand B. , Bagnoud V. , Fils J. , Kühl T. , Lin X. X. , Li C. , Li Y. T. , Roth M. , Neely D. , McKenna P.
Published: October 2011

The angular distribution of energetic electrons emitted from thin foil targets irradiated by intense, picosecond laser pulses is measured as a function of laser incidence angle, intensity, and polarization. Although the escaping fast electron population is found to be predominantly transported along the target surface for incidence angles ≥65°, in agreement with earlier work at lower intensities, rear-surface proton acceleration measurements reveal that a significant electron current is also transported longitudinally within the target, irrespective of incident angle. These findings are of interest to many applications of laser-solid interactions, including advanced schemes for inertial fusion energy.
Mechanical constraints enhance electrical energy densities of soft dielectrics
Authors: Zhang Lin , Wang Qiming , Zhao Xuanhe
Published: October 2011

Dielectrics are essential components in modern electronics and electric systems. When a sufficiently high voltage is applied on a layer of a dielectric, the dielectric will breakdown electrically. The breakdown limits the electrical energy density of the dielectric. We show that constraining the deformation of soft dielectrics can greatly enhance their breakdown electric fields and thus increase their electrical energy densities. The mechanical constraints suppress electromechanical instabilities, a major cause for electrical breakdowns in soft dielectrics.
The covalent bonding interaction in the ferroelectric LuMnO3
Authors: Ahn Suk-Jin , Kim Jinyoung , Shin Namsoo , Koo Yang-Mo
Published: October 2011

The electron density distributions of paraelectric and ferroelectric LuMnO3 are analyzed using high temperature synchrotron x-ray powder diffraction data with the Rietveld method, the maximum entropy method (MEM), and MEM-based pattern fitting. Bonding electrons due to orbital hybridization are clearly seen in the Lu1–O3 and Lu2–O4 bonds along the c-axis polarization direction. The Lu1–O3 bond was determined to be covalent due to hybridization below the ferroelectric transition temperature, and was identified as the driving force for ferroelectricity in LuMnO3. However, the Lu2–O4 bond shows covalent character in both paraelectric and ferroelectric states. Also, we suggest that the Lu2–O4 covalent bonding is responsible for large spontaneous polarization in LuMnO3, associated with the small radius of the Lu3+ ion.
On the anelasticity and strain induced structural changes in a Zr-based bulk metallic glass
Authors: Caron A. , Kawashima A. , Fecht H.-J. , Louzguine-Luzguin D. V. , Inoue A.
Published: October 2011

We report on the anelastic behavior of a cyclically loaded Zr62.5Fe5Cu22.5Al10 bulk metallic glass well below its yield strength. The dynamic mechanical behavior of the glass is discussed on the basis of its structural and thermodynamic properties before and after tests. We show how the kinetically frozen anelastic deformation accumulates at room temperature and causes a structural relaxation and densification of the glass and further leads to its partial crystallization.
Effect of post deposition anneal on the characteristics of HfO2/InP metal-oxide-semiconductor capacitors
Authors: Galatage R. V. , Dong H. , Zhernokletov D. M. , Brennan B. , Hinkle C. L. , Wallace R. M. , Vogel E. M.
Published: October 2011

The interface trap density (Dit) and bonding of the HfO2/InP interface is investigated. The energy distribution of interface states extracted using capacitance-voltage measurements show a peak near midgap in InP and a tail, which extends into the InP conduction band. Both the Dit peak and the conduction band Dit increase with increasing post-deposition annealing temperature. A substantial increase in the native oxides with annealing temperature is observed with x-ray photoelectron spectroscopy. The possible bonding states responsible for the defects are presented.
Cross-streamline migration of a semiflexible polymer in a pressure driven flow
Authors: Reddig S. , Stark H.
Published: October 2011

Experiments and simulations on single α-actin filaments in the Poiseuille flow through a microchannel show that the center-of-mass probability density across the channel assumes a bimodal shape as a result of pronounced cross-streamline migration. We reexamine the problem and perform Brownian dynamics simulations for a bead-spring chain with bending elasticity. Hydrodynamic interactions between the pointlike beads are taken into account by the two-wall Green tensor of the Stokes equations. Our simulations reproduce the bimodal distribution only when hydrodynamic interactions are taken into account. Numerical results on the orientational order of the end-to-end vector of the model polymer are also presented together with analytical hard-needle expressions at zero flow velocity. We derive a Smoluchowski equation for the center-of-mass distribution and carefully analyze the different contributions to the probability current that causes the bimodal distribution. As for flexible polymers, hydrodynamic repulsion explains the depletion at the wall. However, in contrast to flexible polymers, the deterministic drift current mainly determines migration away from the centerline and thereby depletion at the center. Diffusional currents due to a position-dependent diffusivity become less important with increasing polymer stiffness.
Investigation on the origin of the memory effect in metal/organic semiconductor/metal structures
Authors: Sebastian P. , Lindner F. , Walzer K. , Lüssem B. , Leo K.
Published: October 2011

We report on the resistive switching effect in metal/organic semiconductor/metal structures and present a general explanation of the switching mechanism in these devices. The J-V characteristics of metal/tris(8- hydroxyquinolinato)aluminum (Alq3)/metal devices will be discussed and it will be further shown that these sustain only a limited number of switching cycles. Besides Alq3, we also investigate other organic semiconductor materials and obtain a bistable behavior, which is independent of the organic material but dependent on the current injection conditions of the interface between the organic material and the metal top electrode. Further, we investigate the material independent switching effect using impedance spectroscopy and can disclose a transition from capacitive to resistive behavior at switching voltages. We propose that the switching in metal/organic semiconductor/metal structures is caused by the growth and rupture of resistive filaments in the organic semiconductor.
How Older People Relate to the Private Winter Warmth Practices of Their Peers and Why We Should Be Interested
Authors: Hitchings Russell , Day Rosie
Published: October 2011

There is good reason to be interested in how older people in ageing societies organise their winter warmth. Winter mortality rates are highest amongst this group. Several initiatives have accordingly sought to alleviate the fuel poverty some older people experience at this time. Yet many older people are also wealthier than ever. This leads to alternative anxieties about how their potentially extravagant home heating could exacerbate wider climate change. This paper pursues the contention that future policies relating to both issues stand to benefit from a fuller appreciation of how current older person households relate to the private winter warmth practices of their generational peers. Building on studies that explore the dynamics of domestic thermal convention and consider how to engender new sustainable energy norms at home, it presents findings from a serial interview project with a diverse sample of older people in the UK. We consider whether these respondents connected their actions to the idea of a wider generational mode of managing domestic winter warmth and the reasons why they seldom did. We end with the implications of this situation for further research on domestic energy norms and interventions aimed at the winter practices of this growing sector.
Landscapes of Economic Deprivation and Locally Distilled Liquor (Kachasu): An Emerging Milieu of HIV/AIDS Risk in Urban Northern Malawi
Authors: Mkandawire Paul , Luginaah Isaac , Tobias Joshua
Published: October 2011

The paper examines how structural vulnerability to HIV/AIDS in Malawi is produced through a complex interplay of economic, cultural, and political factors operating over relational places within the country as well as in the wider Southern Africa subcontinental landscape. Based on empirical work on an impoverished community in the Chibavi township of Mzuzu City in northern Malawi, and drawing on disciplinary perspectives from social psychology and geography, the study does not only demonstrate how vulnerability to HIV/AIDS in this urban centre emerges from the immediate context of pervasive economic deprivation and ready availability of locally distilled highly potent liquor known as kachasu, but also shows how these social realities are intimately connected with an overlapping set of historic processes operating at various temporal and spatial scales. The paper provides a nuanced understanding of the geographies of vulnerability to the AIDS epidemic in northern Malawi and concludes with relevant policy recommendations.
Encountering Fish, Flows, and Waterscapes through Angling
Authors: Bull Jacob
Published: October 2011

This paper examines the material intertwinings of fish and water. It discusses how the presence of water and fish is simultaneously material and immaterial and examines how the processes and tensions between narratives of fish and water are caught up and inform human encounters with waterscapes. In particular, the paper does three things: first, it highlights the tensions between the angling literature and the practices and performances of angling. Second, it examines how fish embody the material and imaginative aspects of waterscapes, highlighting how fish are shaped to fit in or adapt to ‘environmental quality’ and human expectations. Third, it examines how water may be thought through as ‘fishy’ as made animate by the creatures that dwell there.
Planning by Intermediaries: Making Cities Make Nature in Amsterdam
Authors: Kinder Kimberley
Published: October 2011

This analysis of urban wetland restoration in the Netherlands examines how theories of distributed agency are changing the way planners approach city-building tasks. Illusions of a static, prehuman nature are falling by the wayside, and the negative environmental consequences of urban expansion are gaining notoriety. Green Design strategies that, among other things, espouse bringing nature back into the city alleviate many problems. But ecoconscious planners working on Amsterdam's IJburg neighborhood have set their sights higher by attempting to turn cities into nature's womb. And instead of making this nature directly through nurseries and fisheries, planners are instead working to create a field of action that will spontaneously create wild nature at a considerable distance from planners' hands. In reviewing these experiments, this paper shows how planners marshal lake currents, plant spores, and flying birds alongside bulldozers and cranes to build homes and make wetlands.
Finding Space for Flowing Water in Japan's Densely Populated Landscapes
Authors: Waley Paul , Åberg E Ulrika
Published: October 2011

With its rapidly flowing rivers and plentiful summer rainfall, 20th-century Japan has a history of frequent flooding. The effects on its densely populated flood plains have often been devastating. Japan also has one of the world's landscapes most heavily covered in concrete. In recent decades, however, the Japanese state has turned hesitantly to new techniques of releasing of water into the sea buttressed by a concern for ecological well-being. Its ‘nature-oriented’ river landscaping programme is an attempt to find a more sustainable balance between flowing water and the built terrain, allowing water to make space for itself. Our paper sets this programme in its historical context, relating it back to the premodern period and juxtaposing it to prevalent modernist 20th-century practice. Throughout this paper, we focus on the interweaving of discourse and practice, drawing attention to the ‘idiom’ of river landscaping as well as to the role of the state in defining this idiom. We argue that a sort of reconciliation is occurring between the contrasting discourses and practices of ‘hard’ and ‘green’ engineers.