bluuebunny/crossref_metadata_2025 huggingface dataset:
Deformation propagation in responsive polymer network films
Authors: Ghosh Surya K. , Cherstvy Andrey G. , Metzler Ralf
Published: August 2014

We study the elastic deformations in a cross-linked polymer network film triggered by the binding of submicron particles with a sticky surface, mimicking the interactions of viral pathogens with thin films of stimulus-responsive polymeric materials such as hydrogels. From extensive Langevin Dynamics simulations we quantify how far the network deformations propagate depending on the elasticity parameters of the network and the adhesion strength of the particles. We examine the dynamics of the collective area shrinkage of the network and obtain some simple relations for the associated characteristic decay lengths. A detailed analysis elucidates how the elastic energy of the network is distributed between stretching and compression modes in response to the particle binding. We also examine the force-distance curves of the repulsion or attraction interactions for a pair of sticky particles in the polymer network film as a function of the particle-particle separation. The results of this computational study provide new insight into collective phenomena in soft polymer network films and may, in particular, be applied to applications for visual detection of pathogens such as viruses via a macroscopic response of thin films of cross-linked hydrogels.
Enhanced thermoelectric performance of In-substituted GeSb6Te10 with homologous structure
Authors: Kosuga Atsuko , Nakai Kazuki , Matsuzawa Mie , Fujii Yousuke , Funahashi Ryoji , Tachizawa Takuya , Kubota Yoshiki , Kifune Kouichi
Published: August 2014

We studied the crystal structure and thermoelectric properties of polycrystalline GeInxSb6−xTe10 (x = 0, 0.18, 0.3, and 0.6). Rietveld and Le Bail analyses showed that all compositions crystallized in trigonal structures with a 51-layer period. Substituting In decreased both the lattice and electronic thermal conductivity, as well as markedly increased the Seebeck coefficient. We ascribed this increase to increases in the effective mass of the carriers, likely caused by the formation of additional energy states near the Fermi level. In GeIn0.6Sb5.4Te10, we found a maximum ZT of 0.75 at 710 K, 1.9 times higher than that of GeSb6Te10.
Interferometric and schlieren characterization of the plasmas and shock wave dynamics during laser-triggered discharge in atmospheric air
Authors: Wei Wenfu , Li Xingwen , Wu Jian , Yang Zefeng , Jia Shenli , Qiu Aici
Published: August 2014

This paper describes our efforts to reveal the underlying physics of laser-triggered discharges in atmospheric air using a Mach-Zehnder interferometer and schlieren photography. Unlike the hemispherical shock waves that are produced by laser ablation, bell-like morphologies are observed during laser-triggered discharges. Phase shifts are recovered from the interferograms at a time of 1000 ns by the 2D fast Fourier transform method, and then the values of the refractive index are deduced using the Abel inversion. An abundance of free electrons is expected near the cathode surface. The schlieren photographs visualize the formation of stagnation layers at ∼600 ns in the interaction zones of the laser- and discharge-produced plasmas. Multiple reflected waves are observed at later times with the development of shock wave propagations. Estimations using the Taylor-Sedov self-similar solution indicated that approximately 45.8% and 51.9% of the laser and electrical energies are transferred into the gas flow motions, respectively. Finally, numerical simulations were performed, which successfully reproduced the main features of the experimental observations, and provided valuable insights into the plasma and shock wave dynamics during the laser-triggered discharge.
Large epitaxial bi-axial strain induces a Mott-like phase transition in VO2
Authors: Kittiwatanakul Salinporn , Wolf Stuart A. , Lu Jiwei
Published: August 2014

The metal insulator transition (MIT) in vanadium dioxide (VO2) has been an important topic for recent years. It has been generally agreed upon that the mechanism of the MIT in bulk VO2 is considered to be a collaborative Mott-Peierls transition, however, the effect of strain on the phase transition is much more complicated. In this study, the effect of the large strain on the properties of VO2 films was investigated. One remarkable result is that highly strained epitaxial VO2 thin films were rutile in the insulating state as well as in the metallic state. These highly strained VO2 films underwent an electronic phase transition without the concomitant Peierls transition. Our results also show that a very large tensile strain along the c-axis of rutile VO2 resulted in a phase transition temperature of ∼433 K, much higher than in any previous report. Our findings elicit that the metal insulator transition in VO2 can be driven by an electronic transition alone, rather the typical coupled electronic-structural transition.
Note: High resolution ultra fast high-power pulse generator for inductive load using digital signal processor
Authors: Flaxer Eli
Published: August 2014

We present a new design of a compact, ultra fast, high resolution and high-powered, pulse generator for inductive load, using power MOSFET, dedicated gate driver and a digital signal controller. This design is an improved circuit of our old version controller. We demonstrate the performance of this pulse generator as a driver for a new generation of high-pressure supersonic pulsed valves.
Nanowire light scattering variation induced by magnetic alignment
Authors: Gimenez Alejandro J. , Luna-Bárcenas Gabriel , Sanchez Isaac C. , Martin Yáñez-Limón J.
Published: August 2014

We report the preparation of Ni nanowire colloidal suspension that exhibits large light scattering changes when a magnetic field is applied. These changes occur during the application of alternating transversal magnetic fields. The intensity variation can easily be detected and measured since the light signal produced is very large with ratios much larger compared with signals obtained from light transmission through the nanowire colloidal suspension. Ni nanowires used for the experiments are about 1.2 μm long and 50 nm in diameter; suspensions of 44 μg/ml of these nanowires yield a scattering light variation ratio up to 35% when subjected to transversal alternating magnetic fields of 10 G. The methodology proposed could be implemented to detect and characterize magnetic nanowires even at concentrations as low as 4.4 μg/ml. Using finite element modeling, we observe that nanowires in a suspension scatter light depending strongly on the incidence angle of the applied light. From the finite element simulations, we also observe that nanowires may present plasmonic-antenna absorption effects that can be useful to indirectly measure nanowire properties, such as length and composition.
Effects of ZrO2 doping on HfO2 resistive switching memory characteristics
Authors: Ryu Seung Wook , Cho Seongjae , Park Joonsuk , Kwac Jungsuk , Kim Hyeong Joon , Nishi Yoshio
Published: August 2014

A resistive switching (RS) random access memory device with ZrO2-doped HfO2 exhibits better RS performance than that with pure HfO2. In particular, Ires, Vres, and Vset are reduced by approximately 58%, 38%, and 39%, respectively, when HfO2 is doped with ZrO2 (9 at. %). In addition, the ZrO2 doping in HfO2 makes the distribution of most parameters steeper. Transmission electron microscopy (TEM) analysis reveals that the deposited zirconium-doped hafnium oxide (HZO) (9 at. %) is polycrystalline. Elemental mapping results by scanning TEM–energy dispersive spectroscopy also prove that ZrO2 is uniformly distributed in the HZO (9 at. %) film. The possible mechanism for the improvement in the RS characteristics is also suggested on the basis of the X-ray photoelectron spectroscopy results and filamentary RS mechanism. These results suggest that the ZrO2 doping into HfO2 likely not only will reduce power consumption but also will improve cyclic endurance by controlling the nonstoichiometric phase.
50% continuous-wave wallplug efficiency from 1.53μm-emitting broad-area diode lasers
Authors: Garrod T. , Olson D. , Klaus M. , Zenner C. , Galstad C. , Mawst L. , Botez D.
Published: August 2014

Long-wavelength InP-based diode lasers emitting at 1.53 μm have been optimized for maximum continuous-wave (CW) electrical-to-optical power conversion efficiency, so-called wallplug efficiency (WPE). Efficient electron and hole capture into a single-quantum-well (SQW) active region as well as suppression of electron and hole leakage out of the SQW result in high values for the internal differential efficiency: ∼97% for long-cavity (≥2 mm) uncoated-facet devices and ∼85%–89% for short-cavity (1.5 mm) optimized facet-coated devices. The characteristic temperature of the slope efficiency, T1, reaches a high value of 323 K. Doping-level optimization of the p-cladding layer and the use of the SQW result in low values for the internal loss coefficient: ∼1.1 cm−1 for long-cavity (≥2 mm) uncoated-facet devices and ∼1.5–2.0 cm−1 for short-cavity (1.5 mm) optimized facet-coated devices. In turn, a maximum CW WPE value of 50% is achieved at room temperature and ∼1 W output power from conductively-cooled 100 μm-wide-aperture devices. The maximum CW power is 2.5 W. One beneficial byproduct of the CW-WPE maximization process is a large transverse spot size which, in turn, provides a very narrow transverse beamwidth: 26° full width half maximum. Reliability tests show no degradation when devices are run CW at high currents (4–5 A) and high temperatures (40–50 °C) for over 4000 h, at ∼2 W output power.
Near-resonant second-order nonlinear susceptibility in c-axis oriented ZnO nanorods
Authors: Liu Weiwei , Wang Kai , Long Hua , Chu Sheng , Wang Bing , Lu Peixiang
Published: August 2014

Near-resonant second-harmonic generation (SHG) in c-axis oriented ZnO nanorods is studied under the femtosecond laser with wavelength from 780 nm to 810 nm. A highly efficient SHG is obtained, which is attributed to the d131 component of the second-order nonlinear susceptibility. The largest d131 value is estimated to be 10.2 pm/V at the pumping wavelength of 800 nm, which indicates a large SHG response of the c-axis oriented ZnO nanorods in the near-resonant region. Theoretical calculation based on finite-difference time-domain simulation suggests a four-fold local-field enhancement of the SHG.
Room-temperature detection of a single 19 nm super-paramagnetic nanoparticle with an imaging magnetometer
Authors: Gould Michael , Barbour Russell J. , Thomas Nicole , Arami Hamed , Krishnan Kannan M. , Fu Kai-Mei C.
Published: August 2014

We demonstrate room temperature detection of isolated single 19 nm super-paramagnetic nanoparticles (SPNs) with a wide-field optical microscope platform suitable for biological integration. The particles are made of magnetite (Fe3O4) and are thus non-toxic and biocompatible. Detection is accomplished via optically detected magnetic resonance imaging using nitrogen-vacancy defect centers in diamond, resulting in a DC magnetic field detection limit of 2.4 μT. This marks a large step forward in the detection of SPNs, and we expect that it will allow for the development of magnetic-field-based biosensors capable of detecting a single molecular binding event.
Dual function armchair graphene nanoribbon-based spin-photodetector: Optical spin-valve and light helicity detector
Authors: Ostovari Fatemeh , Moravvej-Farshi Mohammad Kazem
Published: August 2014

We show an armchair graphene nanoribbon channel connected between asymmetric ferromagnetic source-drain structure—i.e., p-type Co/Au/graphene source and n-type Co/Cu/graphene drain—can operate as dual function spin-photodetector, under zero external biases at room temperature. It can function as an optical spin-valve with magnetoresistance of greater than 60% and responsivity as high as 25.12 A/mW, when irradiated by an un-polarized light of energy ∼3.03 eV. Under a circularly polarized illumination, this optical spin-valve can also operate as a light helicity detector. The calculated magnetoresistances for right and left circularly polarized lights are both greater than 60%.
Large electrical manipulation of permittivity in BaTiO3 and Pb(Zr,Ti)O3 bimorph heterostructure
Authors: Ci Penghong , Zhang Li , Liu Guoxi , Dong Shuxiang
Published: August 2014

We report a strain-mediated electric field manipulation of permittivity in BaTiO3 (barium titanate, BT) ceramic by a Pb(Zr,Ti)O3 (PZT) bimorph. This BT/PZT heterostructure exhibited a relatively large permittivity tunability of BT up to ±10% in a wide frequency range under an electric field of ±4 kV/cm applied to the PZT bimorph. The permittivity tunability is attributed to the strain in BT produced by the PZT bimorph. Calculations of the relationship between permittivity and applied electric field were developed, and corresponded well with measurements. The BT/PZT heterostructure has potential for applications in broadband field tunable smart electronic devices.
Polarization dependent asymmetric magneto-resistance features in nanocrystalline diamond films
Authors: Bhattacharyya Somnath , Churochkin Dmitry
Published: August 2014

Polar angle-dependence of magneto-resistance (AMR) in heavily nitrogen-incorporated ultra-nanocrystalline diamond (UNCD) films is recorded by applying high magnetic fields, which shows strong anisotropic features at low temperatures. The temperature-dependence of MR and AMR can reveal transport in the weak-localization regime, which is explained by using a superlattice model for arbitrary values of disorder and angles. While a propagative Fermi surface model explains the negative MR features for low degree of disorder the azimuthal angle-dependent MR shows field dependent anisotropy due to the aligned conducting channels on the layers normal to film growth direction. The analysis of MR and AMR can extract the temperature dependence of dephasing time with respect to the elastic scattering time which not only establishes quasi-two dimensional features in this system but also suggests a potential application in monitoring the performance of UNCD based quantum devices.
Life cycle assessment of ethanol production from tropical banagrass (Pennisetum purpureum) using green and dry processing technologies in Hawaii
Authors: Mochizuki Junko , Yanagida John F. , Kumar Deepak , Takara Devin , Murthy Ganti S.
Published: August 2014

This study conducted well-to-pump and well-to wheel life-cycle assessment of fossil energy use and greenhouse gas (GHG) emissions during ethanol production from tropical Banagrass (Pennisetum purpureum) using green-processing (with the use of fresh feedstocks) and dry or conventional processing (with the use of dried feedstocks) in the state of Hawaii. 10 000 MJ of energy was used as a functional unit with a systematic boundary drawn based on relative mass, energy, and economic value method using a 1% cutoff value, and the results were compared to those of conventional gasoline, and ethanol from corn and other ethanol lignocellulosic feedstocks. Detailed techno-economic model was built using the SuperPro designer. Ethanol yields were estimated at 0.27 l/kg (green processing with fungal co-product), 0.27 l/kg (green processing without co-product), and 0.29 l/kg (dry-processing) of feedstock, respectively. The well-to-pump analysis indicate that ethanol production consume 8200 MJ (green processing with co-product), 7600 MJ (green-processing without co-product) and 7200 MJ (dry-processing without co-product) of fossil energy and emit approximately144 kg CO2-eq., 90.6 kg CO2-eq., and 59.1 kg CO2-eq. per 10 000 MJ of ethanol produced, respectively; well-to-wheel analysis showed that 280 g of gCO2-eq., 260 g CO2-eq., and 250 g CO2-eq. of emissions were produced per kilometer by driving Flex Fuel Vehicle. In summary, ethanol produced using the green-processing technology required greater amount of fossil energy and produced more GHG emissions compared to that of dry processing technology, due to additional energy needed for fungal growth and related processes. Process power, enzyme, and chemical production during ethanol processing were identified as emissions hot-spots for both green and dry processing.
Superstructures of self-assembled multiferroic core-shell nanoparticles and studies on magneto-electric interactions
Authors: Sreenivasulu G. , Petrov V. M. , Chavez F. A. , Srinivasan G.
Published: August 2014

Superstructures of linear chains and arrays of chemically self-assembled core-shell nanoparticles of nickel ferrite and barium titanate have been obtained by magnetic-field-assisted assembly (MFAA). Studies on strain mediated magneto-electric (ME) effects by ME voltage coefficient (MEVC) measurements reveal higher MEVC for MFAA samples than for unassembled films and is higher for magnetic fields parallel to the array orientation than for transverse fields. The strongest ME effect is measured in MFAA-films with a maximum MEVC of 8 mV/cm Oe, one of the highest reported for as-assembled nanocomposite. A model is discussed for the ME coupling in the MFA samples.
First-principles study of the structure of Mg/Nb multilayers
Authors: Kumar Anil , Beyerlein Irene J. , Wang Jian
Published: August 2014

The magnesium (Mg) phase characterized within Mg/Nb multilayers can adopt either a body-centered cubic (bcc-Mg) or hexagonal close packed (hcp-Mg) structure, depending on the Mg layer thickness. Using first-principles density functional theory, we find that bcc-Mg has a similar weight density of hcp-Mg, lower Young's modulus, and higher shear modulus than hcp-Mg, and the same conventional slip systems as the bcc structure. A simple theoretical model is developed to predict the structural stability of both the bcc-Mg/Nb and hcp-Mg/Nb multilayers. It shows that the bcc-Mg/Nb multilayer is energetically favorable when the bcc-Mg layer is less than 4.2 nm.
Analysis of carrier transport and carrier trapping in organic diodes with polyimide-6,13-Bis(triisopropylsilylethynyl)pentacene double-layer by charge modulation spectroscopy and optical second harmonic generation measurement
Authors: Lim Eunju , Taguchi Dai , Iwamoto Mitsumasa
Published: August 2014

We studied the carrier transport and carrier trapping in indium tin oxide/polyimide (PI)/6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene)/Au diodes by using charge modulation spectroscopy (CMS) and time-resolved electric field induced optical second harmonic generation (TR-EFISHG) measurements. TR-EFISHG directly probes the spatial carrier behaviors in the diodes, and CMS is useful in explaining the carrier motion with respect to energy. The results clearly indicate that the injected carriers move across TIPS-pentacene thorough the molecular energy states of TIPS-pentacene and accumulate at the PI/TIPS-pentacene interface. However, some carriers are trapped in the PI layers. These findings take into account the capacitance-voltage and current-voltage characteristics of the diodes.
Transforming Commuting Mobilities: The Memory of Practice
Authors: Bissell David
Published: August 2014

This paper examines how nonrepresentational theories of practice can expand our understanding of the ways in which mobility transformations take place. It argues that we need to attend more sensitively to the different ways in which mobility practices self-transform through their ongoing, repeated enactment. Its central claim is that commuting practices are always evolving, adapting, and elaborating. This is because of the different ways that the past coexists with and complicates action in the present. The first part of the paper shows how mobility transformations are most frequently evaluated according to linear, chronological understandings of temporality. In response, it shows how an attunement to duration, using conceptualisations of the virtual, provides a way of understanding the complex temporal folds through which the past inheres in the present, transforming its course. Pivoting around three interview encounters with commuters in Sydney, Australia, the second part of the paper shows how the virtuality of the past inheres in and becomes actualised in the present through movements, events, and milieus—flagging the significance of habit memory, recollection memory, and tertiary memory, respectively. These virtual potentials underscore not only the complexity and excessiveness of the present, but also the openness and the indeterminacy of the future. The paper questions what constitutes a mobility transformation; it expands our comprehension of the agencies of transformation affecting life in this sphere; and it challenges us to rethink the ontological unit upon which macropolitical interventions are usually focused.
Divergent Paths of Counter-Neoliberalization: Materiality and the Labor Process in Bolivia's Natural Resource Sectors
Authors: Kaup Brent Z
Published: August 2014

Social scientists have often focused upon how transnational corporations and elites mold socioeconomic organization and change in an era of neoliberal globalization. Often overlooked, however, are the active roles played by labor and nature in the construction of contemporary forms of capitalism. Examining the case of Bolivia, this paper explores how the laborers and natures in the country's two dominant economic sectors—hydrocarbons and minerals—shaped the country's neoliberal and counter-neoliberal shifts. I argue that, while both sectors were subjected to similar processes of neoliberalization, the materiality of the natural resources and the labor required to extract them have created divergent paths of counter-neoliberalization with different implications for the scope and reach of post-neoliberal possibilities. In theorizing neoliberal and counter-neoliberal shifts, scholars should thus seek to understand not only changing property rights, regulations, and institutional forms, but also the intimate relationships between commodities and their creators.
Phnom Penh during the Cambodian Genocide: A Case of Selective Urbicide
Authors: Tyner James A , Henkin Samuel , Sirik Savina , Kimsroy Sokvisal
Published: August 2014

Phnom Penh, as it existed during the Cambodian genocide (1975–79), has been held up as a textbook example of urbicide. However, this representation is not entirely accurate, for Phnom Penh remained a vital city during this period. While the depopulation of Phnom Penh during the Cambodian genocide has received considerable analytic attention, decidedly less research has focused on the city as a ‘command-and-control’ node in an integrated space-economy. Far from being a ‘city with no people’, Phnom Penh served as a functioning city and was the catalytic center-point of Khmer Rouge policy and practice. In this paper we begin the task of mapping Phnom Penh as it existed during the years 1975–79. Specifically, we identify and map the location of four broad types of economic institution: administrative, production, distributive, and ancillary. In so doing, we argue that such a geographically informed analysis of Phnom Penh is necessary for it provides the spatial foundation for an understanding of Khmer Rouge practice.
Toward More Inclusive Public Spaces: Learning from the Everyday Experiences of Muslim Arab Women in New York City
Authors: Johnson Asal Mohamadi , Miles Rebecca
Published: August 2014

In this study we examine the spatial practices and lived experiences of an understudied subgroup, observant Muslim women of Arab descent, to explore the extent to which they experience representation and inclusion in the context of Brooklyn, New York. In an attempt to provide a more in-depth understanding of space, we utilize a phenomenological approach in which gender is central. We conceptualize our analysis based on Lefebvre's spatial triad. The narratives of the women in this study elucidate how they interpret and navigate publicly accessible urban spaces as women marked by both ethnicity and religious difference in a multicultural city such as New York. Our study finds that the physical accessibility of public spaces, the aspect that planners tend to emphasize, matters for the observant Muslim women in this study both in ways with which planners are familiar and in other ways. The main aspects of physical accessibility that facilitated their sense of inclusion and engagement in Bay Ridge public spaces are the ease of getting around, often called ‘walkability’ in planning circles, the extent of access to mass transit, and the types of destinations in the area. Streetlights and the openness of public spaces were also critical to participants' lived experiences, as was the presence of a number of women wearing the Islamic headscarf. The latter enabled participants to become active actors in space because they marked a place as culturally, religiously, and socially appropriate for them. Participants' lived experiences (representational space) in turn shaped and were shaped by the characteristics of physical space. For example, well-lit open spaces enabled their spatial engagement because this made them visible to the community and at the same time allowed them to see the community. For immigrant women the Arabic landscape of the neighborhood marked by the Arabic signage, the Arabic language being spoken, and women wearing the Islamic headscarf provided them an opportunity to communicate with other women who share their cultural and religious values (spatial practice), and thereby to experience a safe space of normalcy (representational space).
The benefits of seed enrichment on sandalwood (Santalum spicatum) populations, after 17 years, in semi-arid Western Australia
Authors: Brand Jonathan E. , Sawyer Benjamin , Evans David R.
Published: August 2014

Initially, the size-class structure of 1067 natural sandalwood (Santalum spicatum) trees and seedlings, growing in populations at three semi-arid sites (Burnerbinmah, Ninghan and Goongarrie) in Western Australia, was measured during 1996–97. These same populations, and any new sandalwood seedlings and small trees that had established after 1996–97, were measured again after 17 years (2013). Size-class structure was assessed by measuring over-bark stem diameter at 150 mm above the ground. Populations of sandalwood trees at the Burnerbinmah and Ninghan sites failed to regenerate and, after 17 years, they contained only 0–3% small trees and 0–2% seedlings. Their overall population size declined by 21–24% and, combined with recruitment failure, these natural stands of sandalwood may largely disappear within 50–60 years. At the Goongarrie site, the proportion of large trees within the natural population increased from 58% to 82%. The proportion of small trees was constant at 13–16%, while seedlings declined from 29% to 2%. The population reduced by 35%, mainly due to high seedling mortality. Although the population was in decline, there appeared to be enough small trees and seedlings to maintain the population longer than at both the Burnerbinmah and Ninghan sites.
In a second study, 16 640 sandalwood seeds were sown at the same three sites during 1996–97, and then assessed for germination, survival, growth and fruit production over 17 years. Sandalwood germination and growth were compared between locations, fencing treatments and land systems. Seed enrichment was successful at each site with 27–45% germination and 6–20% survival (from germinated seeds) after 17 years. The overall seedling survival rates (from total seeds sown) ranged from 2.1% to 5.2%. Mean stem diameter of seedlings was significantly larger at Goongarrie (37 mm) than at both Burnerbinmah and Ninghan (20–22 mm) sites. Grazing significantly affected the performance of sandalwood seedlings at an age of 17 years at the Ninghan site. At this site, seedling survival (from germinated seeds) was 16% in the fenced plots compared with only 6% in the unfenced plots. Mean stem diameter in the fenced plots (24 mm) was also significantly greater than in the unfenced plots (11 mm). Land systems did not affect survival of sandalwood seedlings at the Burnerbinmah site but had a significant impact at the Goongarrie site after 17 years. Seedling survival was significantly greater on the hills and ridges than those growing on the plains with granite and red sand plains. Seed-enrichment programs are recommended to improve long-term regeneration and sustainability of sandalwood trees.
Could point-of-care testing be effective for reducing the prevalence of trichomoniasis in remote Aboriginal communities?
Authors: Hui Ben B. , Ward James , Causer Louise , Guy Rebecca J. , Law Matthew G. , Regan David G.
Published: August 2014

High prevalence of trichomoniasis is reported for many remote Indigenous communities despite intensive screening and treatment programs. Mathematical modelling has previously been used to show that point-of-care (POC) testing for gonorrhoea and chlamydia has the potential to increase the impact of screening in reducing the prevalence of these sexually transmissible infections. The study was extended to estimate the impact of a rapid POC test for trichomoniasis. The results suggest that POC testing in place of conventional testing will also provide additional reductions in trichomoniasis prevalence. However, more emphasis should be placed on testing for trichomoniasis in older women due to the high prevalence observed in this group.
Nedd9
restrains renal cystogenesis in
Pkd1

−/−

mice
Authors: Nikonova Anna S. , Plotnikova Olga V. , Serzhanova Victoria , Efimov Andrey , Bogush Igor , Cai Kathy Q. , Hensley Harvey H. , Egleston Brian L. , Klein-Szanto Andres , Seeger-Nukpezah Tamina , Golemis Erica A.
Published: August 2014

Significance

This study uses mouse models for the first time to our knowledge to identify that NEDD9, a nonenzymatic scaffolding protein that is commonly amplified in cancer, has an important restraining function for the development of renal cysts in autosomal dominant polycystic kidney disease (ADPKD). In the absence of NEDD9, failure to activate Aurora-A kinase causes multiple abnormalities in cilia, intensifying the effect of genetic deficiency of mutations in the polycystic kidney disease (PKD) 1 gene, the most common cause of PKD. As important implications, clinical inhibitors of Aurora-A also intensified ADPKD induced by mutation of
PKD1
, suggesting caution in use of these agents, whereas recently reported polymorphisms in Nedd9 may contribute to the genetic heterogeneity of ADPKD presentation in affected families.
Assembly and dynamics of the autophagy-initiating Atg1 complex
Authors: Stjepanovic Goran , Davies Christopher W. , Stanley Robin E. , Ragusa Michael J. , Kim Do Jin , Hurley James H.
Published: August 2014

Significance

Autophagy is conserved and essential for cellular survival during starvation and stress, and is initiated by the autophagy-related 1 (Atg1) complex. In yeast, the three subunits Atg17, Atg29, and Atg31 assemble first, and their structure is known. There has been a debate over how the Atg1 and Atg13 subunits assemble when autophagy is triggered. Here we use mass spectrometry to show that the C-terminal domain of Atg1 is highly dynamic on its own. Atg1 forms a stable complex when it binds with high affinity to Atg13. The combined Atg1–Atg13 subcomplex then binds with moderate affinity to the preformed Atg17–Atg31–Atg29 scaffold. This highlights the binding of Atg1–Atg13 to Atg17–Atg31–Atg29 as a pivotal step in autophagy initiation.
Efficient utilization of complex N-linked glycans is a selective advantage for
Bacteroides fragilis
in extraintestinal infections
Authors: Cao Yanlu , Rocha Edson R. , Smith C. Jeffrey
Published: August 2014

Significance

Human microbiota have a huge impact on health from proper development of the immune system to maintenance of normal physiological processes. The largest concentration of microbes is found in the colon, which is home to hundreds of bacterial species, most of which are obligate anaerobes. This population also poses a significant threat of opportunistic infection, and of all the species present,
Bacteroides fragilis
is the anaerobe most frequently isolated from extraintestinal infections of intestinal origin. The findings presented here describe a unique ability of this species to efficiently deglycosylate complex N-linked glycans from the most abundant glycoproteins found in serum and serous fluid, which gives
B. fragilis
a competitive, nutritional advantage for extraintestinal growth.
Children with autism and composite tactile-visual toys during parent-child interaction
Authors: Ma Min-Yuan , Lee Ya-Hsueh
Published: August 2014

Based on sensory integration theory, six fabric samples containing tactile and visual stimuli were selected using the sensory perceptions of designers and combined with balls. Experiments involving these toys were implemented with 15 families with preschool-aged high-functioning autistic children. The results showed that (a) loose sequin (No. 15), which possessed equal tactile and visual intensities, was strongly correlated with frequent smiling/laughing and high enjoyment levels. The fabric provided a loose tactile sensation regarding surface interweave uniformity and a bright visual sensation regarding visually perceived luster; (b) suede (No. 5) exhibited a greater tactile intensity than visual intensity and was correlated with eye contact and activity response. This fabric possessed a smooth visual sensation regarding visually perceived smoothness; and (c) loose sequin (No. 15), which possessed equal tactile and visual intensities, was highly correlated with finger pointing and initiation. This fabric offered a thin tactile sensation regarding surface interweave thickness and a bright visual sensation regarding visually perceived luster. We suggest applying fabrics to composite toys. Specifically, loose sequin can be used initially to encourage autistic children to interact; subsequently, suede can enable sustained parent-child interaction. The experimental results provide a reference for establishing an innovative toy-design method for autistic children. Keywords: autism; sensory integration theory; parent-child interaction; toys
Metaphoricalparasitesand “parasitic” metaphors
Authors: Musolff Andreas
Published: August 2014

The metaphorical categorization of social and political adversaries as “parasites” has an infamous history in public discourse: For two centuries it has been routinely used for the purpose of racial and socio-political stigmatization. In cognitive accounts, theparasite-metaphorhas usually been treated as an example of semantic transfer from the biological to the social domain. Historically, however, the scientific uses cannot be deemed original or primary, as their emergence in the 17th and 18th centuries was preceded by a much older tradition of religious and social meanings. The paper charts the main traditions of diachronic variation in the discourse history of the parasite-metaphor anddiscusses the implications of its findings regarding the assumption of “uni-directionality” of metaphorization processes, which has been a central tenet of cognitive analyses. In conclusion, we ask whether metaphors in political discourse might fruitfully be viewed as a “parasitic” form of communication.
A cognitive approach to early conservatism
Authors: Fischer Pascal
Published: August 2014

Conservatism is notoriously difficult to define. In the present study, conceptual metaphor theory is used to elucidate the nature of this ideology in its early phase when it emerged in England as a force struggling with the ideas of the French Revolution. It can be shown that conservative authors frequently do not conform to the pattern of orientational metaphors described byGeorge Lakoff and Mark Johnson (1980), according to which “up” is usually regarded as positive and “down” as negative. Conservatives often associate their own ideas with depth or a downward movement, whereas the loathed ideas of the political opponents are related to height or an upward movement. This dichotomy is closely connected to the polarity between solidity, stability and weight on the one hand and gaseity, volatility and lightness on the other. The study bases its analysis on numerous political tracts, pamphlets, and novels from the 1790s and early 1800s.
Cognitive categorization and prototypicality as persuasive strategies
Authors: Schubert Christoph
Published: August 2014

Cognitive categorization is an indispensable instrument for organizing human experience. Owing to the obvious appeal of clear-cut categories in ideological discourse, polarization frequently serves as a strategy of political persuasion. The success of such rhetoric corroborates the allure of dichotomies, although they blatantly contradict the fuzzy nature of cognitive categories. Since prototypicality yields a great cognitive effect but demands only little processing effort, prototypes are particularly convenient in political speeches, where speakers must often get their message across to a wide and heterogeneous audience in a limited time span. Along these lines, the analysis of 32 presidential speeches from Franklin D. Roosevelt to George W. Bush brings to light how the prototypical enemy or national hero is established. This paper aims to show that political rhetoric does not merely reflect existing categorizations but also has the power to shape and perpetuate them in the minds of the target audience.
Denotational boundary disputes in political discourse
Authors: Jäkel Olaf
Published: August 2014

The cognitive semantic analysis of denotational incongruencies by means of comparative investigations of structural field patterns (cf. Jäkel 2001, 2003, 2010) can also be put to use in the investigation of certain kinds of contested concepts (Lakoff 1993), namely cases in which the field patterns themselves are under dispute. The case to be analysed is that of marriage, a cultural concept that has recently come under dispute in the socio-political discourse of Western countries. Competing cultural models (cf. Lakoff 1987) to be compared in this context include the traditional/conservative model as well as different versions of a more tolerant model and a liberal/progressive model. The analysis will focus on authentic language data from the United States, Canada, Great Britain, and Germany, supplemented by a diachronic comparison of dictionary definitions as well as the results of a survey done with young German informants.
Effect of Standardized Surveillance of Intensive Care Unit–Acquired Infections on Ventilator-Associated Pneumonia Incidence
Authors: Bénet Thomas , Ecochard René , Voirin Nicolas , Machut Anaïs , Lepape Alain , Savey Anne , Vanhems Philippe
Published: August 2014

In a multicenter surveillance of intensive care unit (ICU)–acquired infections, adjusted ventilator-associated pneumonia (VAP) incidence diminished by −1.0% per year (95% confidence interval [CI], −1.8 to −0.2; P = .02) in ICUs with continuous surveillance but increased by +16.1% (95% CI, 0.5%–34.1%; P = .04) in the year following surveillance disruption, suggesting a preventive effect of surveillance on VAP.

Infect Control Hosp Epidemiol 2014;35(10):1290–1293
Food Price Shocks and the Political Economy of Global Agricultural and Development Policy
Authors: Guariso Andrea , Squicciarini Mara P. , Swinnen Johan
Published: August 2014

The recent spikes of global food prices induced a rapid increase in mass media coverage, public policy attention, and donor funding for food security and for agriculture and rural poverty. This has occurred while the shift from low to high food prices has induced a shift in (demographic or social) location of the hunger and poverty effects, but the total number of undernourished and poor people has declined over the same period. We suggest that the observed pattern can be explained by the presence of a global urban bias on agriculture and food policy in developing countries, and we discuss whether this global urban bias may actually benefit poor farmers. We argue that the food price spikes have succeeded where others have failed in the past: to move the problems of poor and hungry farmers to the top of the policy agenda and to induce development and donor strategies to help them.
Aspirin Use for Primary and Secondary Prevention in Human Immunodeficiency Virus (HIV)-Infected and HIV-Uninfected Patients
Authors: Suchindran Sujit , Regan Susan , Meigs James B. , Grinspoon Steven K. , Triant Virginia A.
Published: August 2014

Background.  Human immunodeficiency virus (HIV) infection is associated with increased risk of myocardial infarction (MI). The use of aspirin for primary and secondary MI prevention in HIV infection has not been extensively studied.

Methods.  We performed a cross-sectional study of 4037 patients infected with HIV and 36 338 demographics-matched control patients in the Partners HealthCare System HIV cohort. We developed an algorithm to ascertain rates of nonepisodic acetylsalicylic acid (ASA) use using medication and electronic health record free text data. We assessed rates of ASA use among HIV-infected and HIV-uninfected (negative) patients with and without coronary heart disease (CHD).

Results.  Rates of ASA use were lower among HIV-infected compared with HIV-uninfected patients (12.4% vs 15.3%, P < .001), with a relatively greater difference among patients with ≥2 CHD risk factors (22.1% vs 42.4%, P < .001). This finding was present among men and among patients in the 30–39 and 40–49 age groups. Among patients with prevalent CHD using ASA for secondary prevention, rates of ASA use were also lower among HIV-infected patients compared with HIV-uninfected patients (51.6% vs 65.4%, P < .001).

Conclusions.  Rates of ASA use were lower among HIV-infected patients compared with controls, with a greater relative difference among those with elevated CHD risk and those with known CHD. Further studies are needed to investigate the optimal strategies for ASA use among patients infected with HIV.
The Successful Application of a National Peer Advisory Committee for Physicians Who Provide Salvage Regimens to Heavily Antiretroviral-Experienced Patients in Mexican Human Immunodeficiency Virus Clinics
Authors: Calva Juan J. , Sierra-Madero Juan , Soto-Ramírez Luis E. , Aguilar-Salinas Pedro
Published: August 2014

Background.  Designing optimal antiretroviral (ARV) salvage regimens for multiclass drug-resistant, human immunodeficiency virus (HIV)-infected patients demands specific clinical skills. Our aim was to assess the virologic and immunologic effects of the treatment recommendations drafted by a peer advisory board to physicians caring for heavily ARV-experienced patients.

Methods.  We conducted a nationwide, HIV clinic-based, cohort study in Mexico. Adults infected with HIV were assessed for a median of 33 months (interquartile range [IQR] = 22–43 months). These patients had experienced the virologic failure of at least 2 prior ARV regimens and had detectable viremia while currently being treated; their physicians had received therapeutic advice, by a panel of experts, regarding the ARV salvage regimen. The primary endpoint was the incidence of loss of virologic response (plasma HIV-RNA levels of <200 copies per mL, followed by levels above this threshold) during the follow-up assessment using an observed-failure competing risks regression analysis.

Results.  A total of 611 patients were observed (median ARV therapy exposure = 10.5 years; median prior regimens = 4). The probabilities of virologic failure were 11.9%, 14.4%, 16.9%, and 19.4% at the 12-, 24-, 36-, and 48-month follow-up assessments, respectively. Of the 531 patients who achieved a confirmed plasma HIV-RNA level below 200 copies per mL, the median increase in blood CD4+ T-cell count was 162 cells per mL (IQR = 45–304 cells per mL).

Conclusions.  In routine practice, a high rate of patients with extensive ARV experience, who received an optimized salvage regimen recommended by a peer advisory committee, achieved a long-term sustained virologic response and immune reconstitution.
Genotypes and Phenotypic Characterization of Field Fusarium asiaticum Isolates Resistant to Carbendazim in Anhui Province of China
Authors: Chen Yu , Yang Xue , Gu Chun-Yan , Zhang Ai-Fang , Gao Tong-Chun , Zhou Ming-Guo
Published: August 2014

Fusarium asiaticum is a causal agent of Fusarium head blight (FHB) of wheat in the southern part of China. Carbendazim has been extensively used for controlling FHB for more than 30 years, leading to the widespread carbendazim-resistant isolates in all major wheat-producing provinces in China, especially in Anhui Province. F. asiaticum isolates were collected throughout Anhui Province between 2010 and 2012 to monitor their sensitivity to carbendazim. In total, 74 of 899 single-spore isolates F. asiaticum were found to be resistant to carbendazim. Resistant isolates were collected from all of the sampled sites except Hefei of Anhui Province. The overall frequency of carbendazim resistance was shown to be 8.2%. Of the 74 isolates, 1, 68, and 5 had low resistance (LR), moderate resistance (MR) ,and high resistance (HR), respectively, to carbendazim. Five types of point mutations (F167Y, E198L, E198K, F200Y, and E198Q) in the β2-tubulin gene conferring resistance to carbendazim were detected in the field-resistant isolates with frequencies of 89.2, 2.7, 4.1, 2.7, and 1.4%, respectively. The point mutations at codon 167, 198, or 200 of the β2-tubulin gene were correlated with different levels of carbendazim resistance. Some of the sensitive and resistant isolates appeared to possess different biological characteristics; however, these might not be due to resistance. Because carbendazim resistance was generally widespread throughout Anhui Province, the sensitivity of F. asiaticum populations to carbendazim should be constantly monitored for the development of carbendazim resistance in natural populations.
Acoustic Radiation Force Impulse Imaging in Paediatric Patients
Authors: Matos Hugo , Trindade Ana , Noruegas Maria J.
Published: August 2014

Objectives:

The objective of this study was to obtain a normal value for liver shear wave velocities (SWVs) in healthy paediatric patients and to investigate variations concerning age, sex, and different approaches, depths, and lobes of measurements.

Methods:

A total of 150 healthy children (2 months–17 years) were examined with acoustic radiation force impulse (ARFI) technology by an experienced paediatric radiologist, after receiving an informed consent. Measurements obtained were divided according to group age (n = 50, 0–5 years; n = 50, 6–11 years; n = 50, 12–17 years); sex (male–female); lobe (right–left lobe); approach (intercostal–subcostal), and depth of measurements (1–5 and 5–6 cm for the youngest group; 2–6 to 6–8 cm for the 2 other groups). Comparative analyses were performed with measurements obtained at right and left lobes, with different depths and approaches. Differences between age and sex were also analysed.

Results:

Mean SWV in the right liver lobe was 1.07 ± 0.10 m/s. No significant differences were found according to sex or among different probe locations. SWVs were, however, significantly higher within left lobe in comparison with right liver lobe (1.07 ± 0.10 m/s, right; 1.21 ± 0.16 m/s, left). Depth of measurements also influenced SWV values obtained, being slightly lower at deeper locations. Regarding the age significant differences were found for children <6 years old compared with other age groups.

Conclusions:

ARFI analysis seems to be influenced by age, depth, and lobe of measurements. A mean SWV value of 1.07 ± 0.10 m/s for healthy paediatric population with the possibility of reaching 1.12 m/s in the case of younger children was found. ARFI values were more consistently obtained analysing right liver lobe and depths lower than 5 to 6 cm.