bluuebunny/crossref_metadata_2025 huggingface dataset:
On the motives of moduli of chains and Higgs bundles
Authors: García-Prada Oscar , Heinloth Jochen , Schmitt Alexander H.W.
Published: December 2014

We take another approach to Hitchin's strategy of computing the cohomology of moduli spaces of Higgs bundles by localization with respect to the circle action. Our computation is done in the dimensional completion of the Grothendieck ring of varieties and starts by describing the classes of moduli stacks of chains rather than their coarse moduli spaces.

As an application we show that the

n

-torsion of the Jacobian acts trivially on the middle dimensional cohomology of the moduli space of twisted SL

_n

-Higgs bundles of degree coprime to

n

and we give an explicit formula for the motive of the moduli space of Higgs bundles of rank 4 and odd degree. This provides new evidence for a conjecture of Hausel and Rodríguez-Villegas. Along the way we find explicit recursion formulas for the motives of several types of moduli spaces of stable chains.
The Magic of Storytelling: How Curiosity and Aesthetic Preferences Work
Authors: Bianchi Marina
Published: December 2014

Why do we love stories? That this is not an idle question is shown by the fact that we spend an enormous amount of time in our lives following stories: telling and listening to them; reading them; watching them on television or in films or on stage. Despite their recurrent similarity and even predictability, we continue to enjoy them. The paper brings to bear on this question two different strands of current literature in experimental psychology: the literature on aesthetic preferences, and the literature on curiosity and interest. The paper discusses how, in the case of storytelling in particular, though also of creative activities in general, there are two types of curiosity at work: explorative curiosity – associated with investigating new ideas for the simple joy of it and regardless of source – and specific curiosity, corresponding to focused exploration and aimed at solving problems for which the accuracy and relevance of information is of importance. In both cases curiosity is felt as an intensely pleasant experience, which is affected not only by external, but also by the internal stimuli of novelty and challenge. But how does interest/curiosity solidify into preferences that have stability enough to guarantee guidance yet sufficient flexibility to allow for change? The answer explored here highlights the distinction between comfort goods and activities and creative goods and activities. The latter, which allow for complexity, variety and multiplicity of dimensions have a transformative power that allows also for sustained stimulation and interest. The broader aim is to analyze the “behavior” of individual preferences – how they form, how they stabilize, how they change – in the consumption not only of art, the usual focus in discussion of aesthetic preferences, but also of all those goods and activities that can be called creative.
Size-dependent wet removal of black carbon in Canadian biomass burning plumes
Authors: Taylor J. W. , Allan J. D. , Allen G. , Coe H. , Williams P. I. , Flynn M. J. , Le Breton M. , Muller J. B. A. , Percival C. J. , Oram D. , Forster G. , Lee J. D. , Rickard A. R. , Parrington M. , Palmer P. I.
Published: December 2014

Abstract. Wet deposition is the dominant mechanism for removing black carbon (BC) from the atmosphere and is key in determining its atmospheric lifetime, vertical gradient and global transport. Despite the importance of BC in the climate system, especially in terms of its ability to modulate the radiative energy budget, there are few quantitative case studies of wet removal in ambient environments. We present a case study of BC wet removal by examining aerosol size distributions and BC coating properties sampled in three Canadian boreal biomass burning plumes, one of which passed through a precipitating cloud. This depleted the majority of the plume's BC mass, and the largest and most coated BC-containing particles were found to be preferentially removed, suggesting that nucleation scavenging was likely the dominant mechanism. Calculated single-scattering albedo (SSA) showed little variation, as a large number of non-BC particles were also present in the precipitation-affected plume. The remaining BC cores were smaller than those observed in previous studies of BC in post-precipitation outflow over Asia, possibly due to the thick coating by hydrophilic compounds associated with the Canadian biomass burning particles. This study provides measurements of BC size, mixing state and removal efficiency to constrain model parameterisations of BC wet removal in biomass burning regions, which will help to reduce uncertainty in radiative forcing calculations.
Climate extremes in multi-model simulations of stratospheric aerosol and marine cloud brightening climate engineering
Authors: Aswathy V. N. , Boucher O. , Quaas M. , Niemeier U. , Muri H. , Quaas J.
Published: December 2014

Abstract. Simulations from a multi-model ensemble for the RCP4.5 climate change scenario for the 21st century, and for two solar radiation management schemes (stratospheric sulfate injection, G3, and marine cloud brightening, G3SSCE) have been analyzed in terms of changes in the mean and extremes for surface air temperature and precipitation. The climate engineered (SRM 2060s – RCP4.5 2010s) and termination (2080s – 2060s) periods are investigated. During the climate engineering period, both schemes, as intended, offset temperature increases by about 60% globally, but are more effective in the low latitudes and exhibit some residual warming in the Arctic (especially in the case of marine cloud brightening that is only applied in the low latitudes). In both climate engineering scenarios, extreme temperatures changes are similar to the mean temperature changes over much of the globe. The exception is in Northern Hemisphere high latitudes, where high temperatures (90th percentile of the distribution) of climate engineering relative to RCP4.5 rise less than the mean and cold temperatures (10th percentile) much more than the mean. When defining temperature extremes by fixed thresholds, namely number of frost days and summer days, it is found that both climate engineering experiments are not completely alleviating the changes relative to RCP 4.5. The reduction in 2060s dry spell occurrence over land region in G3-SSCE is is more pronounced than over oceans. Experiment G3 exhibits same pattern as G3-SSCE albeit, stronger in magnitude. A strong termination effect is found for the two climate engineering schemes, with large temperature increases especially in the Arctic. Mean temperatures rise faster than the extremes, especially over oceans, with the exception of the Tropics. Conversely precipitation extremes rise much more than the mean, even more so over the ocean, and especially in the Tropics.
Investigating the links between ozone and organic aerosol chemistry in a biomass burning plume from a prescribed fire in California chaparral
Authors: Alvarado M. J. , Lonsdale C. R. , Yokelson R. J. , Akagi S. K. , Coe H. , Craven J. S. , Fischer E. V. , McMeeking G. R. , Seinfeld J. H. , Soni T. , Taylor J. W. , Weise D. R. , Wold C. E.
Published: December 2014

Abstract. Within minutes after emission, rapid, complex photochemistry within a biomass burning smoke plume can cause large changes in the concentrations of ozone (O3) and organic aerosol (OA). Being able to understand and simulate this rapid chemical evolution under a wide variety of conditions is a critical part of forecasting the impact of these fires on air quality, atmospheric composition, and climate. Here we use version 2.1 of the Aerosol Simulation Program (ASP) to simulate the evolution of O3 and secondary organic aerosol (SOA) within a young biomass burning smoke plume from the Williams prescribed burn in chaparral, which was sampled over California in November 2009. We demonstrate the use of a method for simultaneously accounting for the impact of the unidentified semi-volatile to extremely low volatility organic compounds (here collectively called "SVOCs") on the formation of OA (using the Volatility Basis Set) and O3 (using the concept of mechanistic reactivity). We show that this method can successfully simulate the observations of O3, OA, PAN, NOx, and C2H4 to within measurement uncertainty using reasonable assumptions about the chemistry of the unidentified SVOCs. These assumptions were: (1) a~reaction rate constant with OH of ~10−11cm3s−1, (2) a significant fraction (~50%) of the RO2 + NO reaction resulted in fragmentation, rather than functionalization, of the parent SVOC, (3) ~1.1 molecules of O3 were formed for every molecule of SVOC that reacted, (4) ~60% of the OH that reacted with the unidentified SVOCs was regenerated as HO2, and (5) that ~50% of the NO that reacted with the SVOC peroxy radicals was lost, presumably to organic nitrate formation. Additional evidence for the fragmentation pathway is provided by the observed rate of formation of acetic acid, which is consistent with our assumed fragmentation rate. This method could provide a way for classifying different smoke plume observations in terms of the average chemistry of their SVOCs, and could be used to study how the chemistry of these compounds (and the O3 and OA they form) varies between plumes.
The diurnal variation in stratospheric ozone from the MACC reanalysis, the ERA-Interim reanalysis, WACCM and Earth observation data: characteristics and intercomparison
Authors: Schanz A. , Hocke K. , Kämpfer N. , Chabrillat S. , Inness A. , Palm M. , Notholt J. , Boyd I. , Parrish A. , Kasai Y.
Published: December 2014

Abstract. In this study we compare the diurnal variation in stratospheric ozone derived from free-running simulations of the Whole Atmosphere Community Climate Model (WACCM) and from reanalysis data of the atmospheric service MACC (Monitoring Atmospheric Composition and Climate) which both use a similar stratospheric chemistry module. We find good agreement between WACCM and the MACC reanalysis for the diurnal ozone variation in the high-latitude summer stratosphere based on photochemistry. In addition, we consult the ozone data product of the ERA-Interim reanalysis. The ERA-Interim reanalysis ozone system with its long-term ozone parametrization can not capture these diurnal variations in the upper stratosphere that are due to photochemistry. The good dynamics representations, however, reflects well dynamically induced ozone variations in the lower stratosphere. For the high-latitude winter stratosphere we describe a novel feature of diurnal variation in ozone where changes of up to 46.6% (3.3 ppmv) occur in monthly mean data. For this effect good agreement between the ERA-Interim reanalysis and the MACC reanalysis suggest quite similar diurnal advection processes of ozone. The free-running WACCM model seriously underestimates the role of diurnal advection processes at the polar vortex at the two tested resolutions. The intercomparison of the MACC reanalysis and the ERA-Interim reanalysis demonstrates how global reanalyses can benefit from a chemical representation held by a chemical transport model. The MACC reanalysis provides an unprecedented description of the dynamics and photochemistry of the diurnal variation of stratospheric ozone which is of high interest for ozone trend analysis and research on atmospheric tides. We confirm the diurnal variation in ozone at 5 hPa by observations of the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) experiment and selected sites of the Network for Detection of Atmospheric Composition Change (NDACC). The latter give valuable insight even to diurnal variation of ozone in the polar winter stratosphere.
Alone inside: solitary confinement and the ontology of the individual in modern life
Authors: Story B.
Published: December 2014

Abstract. The long-term solitary confinement of prisoners causes fundamentally debilitative psychological damage. This violence, inherent to the socio-spatial organization of solitary confinement, diminishes prisoners' capacity to function as human beings. Yet while violence might characterize the ends of solitary confinement, individuation defines the means. This paper argues that solitary confinement, while an extreme case, shares crucial characteristics with other spaces, structures, and modes of organization familiar to Western society. The actual experiences of prisoners subjected to conditions of total isolation, moreover, contradict the prevailing ontology of the individuated subject. The irreconcilability of this paradox invites inquiry into the political and material problematic of individualism itself. The violence of solitary confinement's spatial practice therefore holds important implications for a critical reassessment of any or all socially isolating institutions and individuating ideologies within the structural fabric of modern life.
Earthquake-induced deformation estimation of earth dam by multitemporal SAR interferometry: the Mornos Dam case (Central Greece)
Authors: Neokosmidis S. , Elias P. , Parcharidis I. , Briole P.
Published: December 2014

Abstract. The scope of this paper concerns the investigation of Mornos earth Dam (Central Greece) deformation induced by major earthquake events occur in the broader area. For this purpose multitemporal SAR interferometry method was used. Specifically, the technique of Differential Interferometry SBAS and for the time series analysis the Singular Value Decomposition algorithm were applied. The data used were ascending and descending acquisitions of AMI / ERS-1 & 2 and ASAR / ENVISAT scenes covering the period 1993–2010. Five very strong seismic events with epicenters close to the dam, at the same period, were consider as potential sources of deformation. Lake level changes were also considered as an additional factor of induced deformation. Results show a maximum deformation rate of 10 cm along the line of sight for the whole period. Although the observed deformation appears to be due to changes in water level following a particular pattern, there are discontinuous over time which coincide with specific seismic events.
MECHANICAL PROPERTIES OF A POLYURETHANE/MONTMORILLONITE NANOCOMPOSITE FEATURING ORGANOMODIFICATION SYNTHESIZED VIA IN SITU POLYMERIZATION
Authors: Bagheri Rouhollah , Darvishi Reza
Published: December 2014

In this study, polyurethane (PU)/organomodified montmorillonite (cloisite®30B) is synthesized via in situ polymerization by reaction of an ether-based prepolymer with the isocyanate end groups and adiamine chain extender (4, 4-methylene-bis(2-chloroaniline)) in the presence of different amounts of nanoparticles dispersed in the prepolymer matrix by an ultrasonic mixer for 1 h. The synthesized polymers are cast on a pretreated carbon steel sheet and cured at 120 °C in an oven. The PU and its composites have been characterized by using Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and mechanical testing. The XRD analysis of the cured samples containing 1 to 3 wt% cloisite30B showed intercalation segments in the silicate layers and exfoliation for 0.5 wt% nanoparticles. The highest mechanical properties were obtained using the cured exfoliated silicate layer sample. A twofold increase in the ultimate tensile strength and a 2.3 times increase in the adhesion strength were found for 0.5 wt% organoclay/PU as compared with that of pure PU. In addition, the exfoliated structure sample exhibited a 16% reduction in abrasion compared with that of pure PU.
Grazing by sheep Ovis aries reduces island populations of water voles Arvicola amphibius
Authors: Frafjord Karl
Published: December 2014

The population of water voles Arvicola amphibius was surveyed on 21 islands in the Solvær archipelago, northern Norway, in August 2012; 11 islands with semi-wild domestic sheep Ovis aries and 10 islands without sheep. Signs from water voles are very easy to detect and were used as a measure of the population (on a scale 0-10), and the numbers of sheep were counted. The ranking of signs on islands with and without sheep was compared, and a significant difference was found. Islands with sheep had, with one exception, only very small and fragmented populations of water voles, the one exception being a fairly large Carex swamp that was not grazed by the sheep and where a moderate-sized population of voles was found. Islands without sheep had much larger populations of water voles, giving a ranking about four times higher. One reason for the devastating effect of sheep on water voles is probably the fact that the sheep are living year-round on these islands with no supplemental food.
End User Privacy and Policy-Based Networking
Authors: Paterson Nancy E.
Published: December 2014

Are privacy concerns over end user surveillance by network operators such as AT&T and Verizon, and by “edge providers” such as Google and Amazon, being dangerously overshadowed by the predominant emphasis on government surveillance? Quite possibly so, Professor Paterson concludes, after reviewing currently-used packet analysis technologies and their advertised capabilities. Paterson concludes that the problem faced by privacy and public interest advocates is that no one has a truly comprehensive grasp of how widely network operators have deployed such tools, what information is collected, or how it is put to use. Paterson asserts that the potential risks call for additional vigorous research in this area.
European Union Media Policy and Independent Regulatory Authorities: A New Tool to Protect European Media Pluralism?
Authors: Llorens Carles , Costache Andreea Madalina
Published: December 2014

Can a uniform policy for media pluralism be adopted across the 28 Member States of the European Union through the involvement of independent regulatory authorities? According to the authors, the chances remain remote due to political and stakeholder opposition grounded in diverse structural, cultural, political, and economic interests. Based on a review of key documents from diverse sources, and case studies in Hungary and Italy, it appears that the goal of an EU-wide collaborative network of financially and politically independent audiovisual regulatory authorities, with common standards, faces significant challenges. However, the authors see hope in the increased debate on the topic, and suggest that some movement in that direction may yet be possible.
Pitfalls and Obstacles of Media Policymaking in an Age of Digital Convergence: The Flemish Signal Integrity Case
Authors: Van den Bulck Hilde , Donders Karen
Published: December 2014

Technological convergence is remaking and even erasing the borders between industries once considered separate, and is forcing policymakers to evolve new regulatory frameworks for a rapidly changing industrial environment. Using the advocacy coalition framework, the authors investigate a struggle by Flemish broadcasters against video distributors to protect the integrity of their broadcast signals. The authors argue that the case may be an indicator of the struggles to come as the television space struggles with convergence, with implications for the European Union and other regions.
e-Democracy: Exploring the Current Stage of e-Government
Authors: van der Meer Toni G.L.A. , Gelders Dave , Rotthier Sabine
Published: December 2014

Governments around the world have been pressured to implement e-Government programs in order to improve the government-citizen dialogue. The authors of this article review prior literature on such efforts to find if they lead to increased democratic participation (“e-Democracy”) for the affected citizens, with a focus on the key concepts of transparency, openness, and engagement. The authors find that such efforts are a starting point toward e-Democracy, but the journey is far from complete.
Philosophy as Self-Transformation: Shusterman's Somaesthetics and Dependent Bodies
Authors: Welsh Talia
Published: December 2014

This article takes up Richard Shusterman's somaesthetics as a way in which philosophy can be prescriptive about everyday embodiment. Popular self-help literature also promotes directed self-mastery, but it is often beholden to unquestioned norms and dualist ideas about the mind dominating the body. Somaesthetics encourages bodily self-mastery without dualism or social obedience. This article argues that in directed bodily self-transformation, such as somaesthetic discipline, one discovers one's vulnerability and dependency as much as one's strength. In conclusion, this article notes that human weakness and dependency circumscribe the reach of Shusterman's original idea of somaesthetics as always promoting individual flourishing. Instead, careful attention to embodiment leads to a realization of weakness. Somaesthetic practices are ways not simply to better lives but also to destabilize them.
Transgression, Plurality, and the Romance of Philosophy
Authors: Morgan Marcia
Published: December 2014

In this article I seek to underscore the ethical obligations of transgression and dissensus internal to our discursive practices, with the aim of facilitating plurality and renewing the romantic philosophic engagement with ethical subjectivity in the tradition of Kantian aesthetics. My investigation is motivated by a return to Adorno and the nonidentical, but in a way that considers new developments in an aesthetic framework of discourse-theoretic ethics. The relationship of Kantian judgment to the nonidentical stands at the foreground of recent aesthetic iterations that open up or heighten our discursive obligation toward “the otherness of the other,” the uniqueness of the human being, and the need for radical politics. I conclude by investigating the critical value of the concept of critique, which stands at the heart of Kantian judgment. The aim of my article is to emphasize the significance of the interrelationship among plurality, transgression, and critique and to reawaken the need for praxis through the tension internal to a sensus communis enlivened by both consensus and dissent.
Thrombin generation and rotational thromboelastometry in the healthy adult population
Authors: Schneider T. , Siegemund T. , Siegemund R. , Petros S.
Published: December 2014

Published data on thrombin generation variables and their correlation with thrombo - elastometry in the healthy population are scarce. This study aimed at assessing thrombin generation in adults and its correlation to classical rotational thromboelastometry (ROTEM).

Thrombin generation was measured in platelet-poor plasma from healthy volunteers using the calibrated automated thrombogram (CAT) with 1 and 5 pmol/l tissue factor final concentration. Lag time, thrombin peak, time to thrombin peak and endogenous thrombin potential (ETP) were analyzed. ROTEM was performed without activator (NATEM) and data for clotting time, alpha angle, clot formation time and maximum clot firmness were correlated with those of thrombin generation.

Altogether 132 persons (72 men, 60 women; median age: 48.0 years) were included. There was a positive non-linear correlation for age versus lag time (p < 0.001) and time to peak (p = 0.001), and almost linear correlation for age versus thrombin peak (p = 0.024) and ETP (p = 0.001), although with a moderate regression slope. Regarding ROTEM, there was a positive correlation between age and maximum clot firmness and alpha angle (p = 0.001), but a negative correlation between age and clotting time (p = 0.039). Comparing both assays, thrombin peak and ETP measured with a final tissue factor concentration of 5 pmol/l correlated significantly with alpha angle and maximum clot firmness.

The age-related changes in CAT and ROTEM variables among adults are not linear. There is a significant correlation, although with a moderate slope, between data from CAT measured with 5 pmol/l tissue factor and ROTEM.
Causaal verband in whiplashzaken: een beschouwing vanuit juridisch en medisch perspectief
Authors: Oskam P. , Reitsma A.M.
Published: December 2014

Causaal verband in whiplashzaken: een beschouwing vanuit juridisch en medisch perspectief

In deze bijdrage wordt de recente rechtspraak in whiplashzaken besproken. De huidige lijn in de rechtspraak wordt vervolgens zowel vanuit juridisch als vanuit medisch perspectief belicht, waarbij onder meer aandacht wordt besteed aan de richtlijnen van de NVN en de behandelbaarheid van subjectieve gezondheidsklachten. De auteurs gaan onder meer in op de vragen of de huidige lijn in de rechtspraak wel een gewenste ontwikkeling is en of de rechter niet te veel zijn eigen (niet medische onderbouwde) weg gaat in whiplashzaken. De auteurs pleiten voor het aannemen van een beperkte looptijd in whiplashzaken.
Réification et massification du capital financier : une contribution à la théorie critique de la financiarisation à partir de l’analyse de la titrisation
Authors: Pineault Éric
Published: December 2014

La finance de masse est devenue une structure essentielle du capitalisme avancé, d’une position interstitielle pendant l’accumulation fordiste, elle est maintenant une régulation centrale d’un régime d’accumulation financiarisée. Cette finance de masse sert d’assise à la titrisation des créances des ménages, pratique à l’origine de la crise financière de 2008, mais depuis ayant été normalisée comme régulation économique de la relation de crédit de masse. La titrisation est ici abordé à partir du concept de réification que Marx construit dans le cadre de son analyse de l’accumulation financière. Nous suivons le processus de production de capital financier liquide dans le cadre de la réification des relations de crédit.
Formamide
Authors: Höhn A. , by Staff Updated
Published: December 2014

Formamide is the first member of the primary amide series and is the only one liquid at room temperature. Formamide is mainly manufactured either by direct synthesis from carbon monoxide or more importantly in a two‐stage process from carbon monoxide and ammonia. The major producers of formamide are located in China. The shelf life is unlimited in sealed containers, but the storage container must be tightly sealed and kept in a cool well‐ventilated area. It exhibits no particular acute toxicity with oral and dermal application. Formamide has a wide variety of applications. It is an intermediate in the chemical industry where it is used to produce heterocyclic compounds, hydrocyanic acid, pharmaceuticals, sulfa drugs, crop protection, and as a solvent. Formamide, deionized, is also used in hybridization reactions and in molecular biology as a denaturing agents for nucleic acids.
Big Data and Positive Change in the Developing World
Authors: Taylor Linnet , Cowls Josh , Schroeder Ralph , Meyer Eric T.
Published: December 2014

This paper is the product of a workshop that brought together practitioners, researchers, and data experts to discuss how big data is becoming a resource for positive social change in low‐ and middle‐income countries (LMICs). We include in our definition of big data sources such as social media data, mobile phone use records, digitally mediated transactions, online news media sources, and administrative records. We argue that there are four main areas where big data has potential for promoting positive social change: advocacy; analysis and prediction; facilitating information exchange; and promoting accountability and transparency. These areas all have particular challenges and possibilities, but there are also issues shared across them, such as open data and privacy concerns. Big data is shaping up to be one of the key battlefields of our time, and the paper argues that this is therefore an opportune moment for civil society groups in particular to become a larger part of the conversation about the use of big data, since questions about the asymmetries of power involved are especially urgent in these uses in LMICs. Civil society groups are also currently underrepresented in debates about privacy and the rights of technology users, which are dominated by corporations, governments and nongovernmental organizations in the Global North. We conclude by offering some lessons drawn from a number of case studies that represent the current state‐of‐the‐art.
Role of PbSe Structural Stabilization in Photovoltaic Cells
Authors: Asil Demet , Walker Brian J. , Ehrler Bruno , Vaynzof Yana , Sepe Alessandro , Bayliss Sam , Sadhanala Aditya , Chow Philip C. Y. , Hopkinson Paul E. , Steiner Ullrich , Greenham Neil C. , Friend Richard H.
Published: December 2014

Semiconductor nanocrystals are promising materials for printed optoelectronic devices, but their high surface areas are susceptible to forming defects that hinder charge carrier transport. Furthermore, correlation of chalcogenide nanocrystal (NC) material properties with solar cell operation is not straightforward due to the disorder often induced into NC films during processing. Here, an improvement in long‐range ordering of PbSe NCs symmetry that results from halide surface passivation is described, and the effects on chemical, optical, and photovoltaic device properties are investigated. Notably, this passivation method leads to a nanometer‐scale rearrangement of PbSe NCs during ligand exchange, improving the long‐range ordering of nanocrystal symmetry entirely with inorganic surface chemistry. Solar cells constructed with a variety of architectures show varying improvement and suggest that triplet formation and ionization, rather than carrier transport, is the limiting factor in singlet fission solar cells. Compared to existing protocols, our synthesis leads to PbSe nanocrystals with surface‐bound chloride ions, reduced sub‐bandgap absorption and robust materials and devices that retain performance characteristics many hours longer than their unpassivated counterparts.
Understanding the Influence of Lattice Composition on the Photocatalytic Activity of Defect‐Pyrochlore‐Structured Semiconductor Mixed Oxides
Authors: Schwertmann Larissa , Grünert Anna , Pougin Anna , Sun Chenghua , Wark Michael , Marschall Roland
Published: December 2014

The defect‐pyrochlore‐structured photocatalyst CsTaWO6 is an ideal starting material for anion doping from the gas phase, and is known to be highly active for solar hydrogen generation under simulated sunlight without co‐catalysts. To investigate the active site of CsTaWO6 for hydrogen generation and to understand the effects of the two d0 elements in the compound, systematic and successive element substitution of tantalum and tungsten on the crystallographic 16c sites of the starting material has been performed. Substituting lattice tantalum with niobium hardly changes the band gap of the resulting compounds CsTa(1 −x)Nb
x
WO6, but the photocatalytic activity for hydrogen generation and oxidation reactions is strongly influenced. By investigating the surface reactivity toward adsorption, surface effects altering the activity are identified. In contrast, substituting lattice tungsten with molybdenum reduces the band gap of CsTaWO6 into the visible‐light range. Materials containing Mo are however not able to generate hydrogen anymore, due to the altered conduction band positions proven by density functional theory calculations. CsTaMoO6 exhibits a band gap of 2.9 eV and evolves oxygen efficiently under UV light irradiation after CoPi co‐catalyst deposition, and even under visible light small amounts of oxygen.
Spatial Control of Cell Gene Expression by siRNA Gradients in Biodegradable Hydrogels
Authors: Hill Michael C. , Nguyen Minh K. , Jeon Oju , Alsberg Eben
Published: December 2014

The extracellular environment exposes cells to numerous biochemical and physical signals that regulate their behavior. Strategies for generating continuous gradients of signals in biomaterials may allow for spatial control and patterning of cell behavior, and ultimately aid in the engineering of complex tissues. Short interfering RNA (siRNA) can regulate gene expression by silencing specific mRNA molecules post‐transcriptionally, which may be valuable when presented in a continuous gradient for regenerative or therapeutic applications. Here, a biodegradable hydrogel system containing a gradient of siRNA is presented, and its capacity to regulate protein expression of encapsulated cells in a spatially continuous manner is demonstrated. Photocross‐linkable dextran hydrogels containing a gradient of siRNA have been successfully fabricated using a dual‐programmable syringe pump system, and differential gene silencing in incorporated cells that is sustained over time has been shown using green fluorescent protein as a reporter. This platform technology may be applied in tissue engineering to spatially control biologically relevant cellular processes.
Light‐Mediated Activation of siRNA Release in Diblock Copolymer Assemblies for Controlled Gene Silencing
Authors: Foster Abbygail A. , Greco Chad T. , Green Matthew D. , Epps Thomas H. , Sullivan Millicent O.
Published: December 2014

Controllable release is particularly important for the delivery of small interfering RNA (siRNA), as siRNAs have a high susceptibility to enzymatic degradation if release is premature, yet lack silencing activity if they remain inaccessible within the cytoplasm. To overcome these hurdles, novel and tailorable mPEG‐b‐poly(5‐(3‐(amino)propoxy)‐2‐nitrobenzyl methacrylate) (mPEG‐b‐P(APNBMA)) diblock copolymers containing light‐sensitive o‐nitrobenzyl moieties and pendant amines are employed to provide both efficient siRNA binding, via electrostatic and hydrophobic interactions, as well as triggered charge reversal and nucleic acid release. In particular, siRNA/mPEG‐b‐P(APNBMA)23.6 polyplexes show minimal aggregation in physiological salt and serum, and enhanced resistance to polyanion‐induced unpackaging compared to polyethylenimine preparations. Cellular delivery of siRNA/mPEG‐b‐P(APNBMA)23.6 polyplexes reveals greater than 80% cellular transfection, as well as rapid and widespread cytoplasmic distribution. Additionally, UV irradiation indicates ≈70% reduction in targeted gene expression following siRNA/mPEG‐b‐P(APNBMA)23.6 polyplex treatment, as compared to 0% reduction in polyplex‐treated cells without UV irradiation, and only ≈30% reduction for Lipofectamine‐treated cells. The results here highlight the potential of these light‐sensitive copolymers with a well‐defined on/off switch for applications including cellular patterning for guided cell growth and extension, and cellular microarrays for exploring protein and drug interactions that require enhanced spatiotemporal control of gene activation.
Silver(I)‐Mediated CH Amination of 2‐Alkenylanilines: Unique Solvent‐Dependent Migratory Aptitude
Authors: Youn So Won , Ko Tae Yun , Jang Min Jung , Jang Su San
Published: December 2014

A highly effective silver(I)‐mediated CH amination of 2‐alkenylanilines has been developed to afford a diverse range of substituted indoles. High functional group tolerance, broad substrate scope, simple/fast/high‐yielding reaction, and recovery/reuse of the inexpensive silver oxidant are noteworthy. Furthermore, an uncommon migratory process of β‐monosubstituted 2‐alkenylanilines with solvent‐dependence was demonstrated.

magnified image
A Practical Way to Prepare Isobutyronitrile Amides through Reactions between Carboxylic Acids and Azobisisobutyronitrile
Authors: Rong Guangwei , Liu Defu , Yan Hong , Chen Jie , Zheng Yang , Zhang Guoqi , Mao Jincheng
Published: December 2014

A practical and efficient synthesis of N‐isobutyronitrile amides has been achieved through the direct condensation of carboxylic acid and azobisisobutyronitrile (AIBN). Carboxylic acids bearing variously substituted phenyl rings and cinnamic or phenylpropiolic acids were employed to furnish both tertiary and secondary isobutyronitrile amides in moderate to high yields. A radical pathway was proposed. The methodology presented here requires no catalysts and additives, and represents the first practical approach to a variety of valuable amides containing the isobutyronitrile structural unit.

magnified image
Ultrathin Anatase TiO2 Nanosheets Embedded with TiO2‐B Nanodomains for Lithium‐Ion Storage: Capacity Enhancement by Phase Boundaries
Authors: Wu Qili , Xu Jungu , Yang Xianfeng , Lu Fengqi , He Shiman , Yang Jingling , Fan Hong Jin , Wu Mingmei
Published: December 2014

A new form of TiO2 microspheres comprised of anatase/TiO2‐B ultrathin composite nanosheets has been synthesized successfully and used as Li‐ion storage electrode material. By comparison between samples obtained with different annealing temperatures, it is demonstrated that the anatase/TiO2‐B coherent interfaces may contribute additional lithium storage venues due to a favorable charge separation at the boundary between the two phases. The as‐prepared hierarchical nanostructures show capacities of 180 and 110 mAh g−1 after 1000 cycles at current densities of 3400 and 8500 mA g−1. The ultrathin nanosheet structure which provides short lithium diffusion length and high electrode/electrolyte contact area also accounts for the high capacity and long‐cycle stability.
Energy Harvesting Technologies for Tire Pressure Monitoring Systems
Authors: Bowen C. R. , Arafa M. H.
Published: December 2014

Tire pressure monitoring systems (TPMS) are becoming increasingly important to ensure safe and efficient use of tires in the automotive sector. A typical TPMS system consists of a battery powered wireless sensor, as part of the tire, and a remote receiver to collect sensor data, such as pressure and temperature. In order to provide a maintenance‐free and battery‐less sensor solution there is growing interest in using energy harvesting technologies to provide power for TPMS. This paper summarizes the current literature and discusses the use of piezoelectric, electromagnetic, electret and triboelectric materials in a variety of harvesting systems.
High Performance Flexible Supercapacitor Electrodes Composed of Ultralarge Graphene Sheets and Vanadium Dioxide
Authors: Lee Myungsup , Wee Boon‐Hong , Hong Jong‐Dal
Published: December 2014

Little is known regarding the effect of the graphene lateral size on the electrochemical performance of hybrid graphene electrode. This work examines the electrochemical performance of a flexible hybrid supercapacitor electrode composed of ultralarge graphene oxide (UGO; mean lateral size of 47 ± 22 μm) and vanadium dioxide (VO2) nanobelts, referring to a reference electrode composed of small scale graphene oxide (SGO; mean lateral size of 0.8 ± 0.5 μm) and VO2.Thermal treatment converts UGO/VO2 and SGO/VO2 to URGO/VO2 (denoted VURGO) and SRGO/VO2 (denoted VSRGO) electrodes, respectively. The sheet resistance of the VURGO film (0.57 ± 0.03 kΩ sq.–1) was two orders of magnitude lower than that of the VSRGO (55.74 ± 9.35 kΩ sq.–1). The VURGO hybrid electrode showed a specific capacitance of 769 F g−1, which was significantly better than the corresponding values for the VSRGO electrode (385 F/g). These results support the notion that the use of ultralarge graphene sheets (≈22 500 μm2) lowers the intersheet resistance due to the presence of fewer intersheet tunneling barriers. This article highlights the potential utility of URGO (as a conductive support) in hybrid electrode containing VO2 nanobelts for high performance flexible hybrid supercapacitor.
Analysis and optimization of pressure retarded osmosis for power generation
Authors: Li Mingheng
Published: December 2014

Model‐based analysis and optimization of pressure retarded osmosis (PRO) for power generation is focused. The effects of membrane properties (hydraulic permeability and mass‐transfer characteristics), design conditions (inlet osmotic pressures, inlet flows, and membrane area) and operating condition (applied pressure) on power density and efficiency are systematically investigated. A dimensionless design parameter
, originally developed in analysis and optimization of reverse osmosis, is used to quantify the effect of dilution in draw solution (DS) as water permeates through membrane. An optimization method is developed to maximize PRO performance. It is shown that dilution and concentration polarization significantly reduce the maximum power density, and the optimal
shifts away from
. Moreover, power density and efficiency follow opposite trends when varying process conditions including DS flow rate and membrane area. Enhancing membrane properties is crucial to improve the economic feasibility of PRO. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1233–1241, 2015
Impact of the diffusion limitation in microphotoreactors
Authors: Aillet Tristan , Loubière Karine , Prat Laurent , Dechy‐Cabaret Odile
Published: December 2014

This publication describes a model that aims (1) to predict the performances (conversion, photonic efficiency) of a photochemical reaction at the outlet of a microreactor. To achieve this, a set of equations that couple mass transport, radiative transfer, and kinetic equations is established and solved, considering (1) a two‐dimensional geometry and (2) a simple monomolecular photoreaction
, where the species A and B are in competition for absorbing incident photons. The model is expressed using classical dimensionless numbers, such as the Damköhler I and II numbers, the absorbance, and the competitive absorption factor. The results show how and why, when competitive absorption exists, the occurrence of diffusion limitations (
) can severely impact the conversion of the photochemical reaction and the photonic efficiency. Consequently, a diagram is proposed as a practical tool for selecting operating conditions subsequently avoiding these limitations. © 2015 American Institute of Chemical Engineers AIChE J, 61: 1284–1299, 2015
Phase I/II trial of the combination of midostaurin (PKC412) and 5‐azacytidine for patients with acute myeloid leukemia and myelodysplastic syndrome
Authors: Strati Paolo , Kantarjian Hagop , Ravandi Farhad , Nazha Aziz , Borthakur Gautam , Daver Naval , Kadia Tapan , Estrov Zeev , Garcia‐Manero Guillermo , Konopleva Marina , Rajkhowa Trivikram , Durand Menda , Andreeff Michael , Levis Mark , Cortes Jorge
Published: December 2014

We investigated the combination of midostaurin and azacitidine (AZA) in patients with acute myeloid leukemia (AML) and high risk myelodysplastic syndrome (MDS). Patients received AZA 75 mg m−2 on days 1–7 and midostaurin 25 mg bid (in cohort 1 of phase I) or 50 mg bid (in cohort 2 of Phase I and in Phase II) orally on day 8–21 during the first cycle and continuously thereafter. Fourteen patients were enrolled in the phase I and 40 in the phase II. Overall response rate was 26%. The median remission duration (RD) was 20 weeks and was significantly longer in patients with FLT3 mutations not previously exposed to other FLT3 inhibitors (P = 0.05) and in patients not previously transplanted (P = 0.01). Thirty‐two (59%) patients have died, all of complications related to disease progression. G3‐4 nonhematological toxicity was reported in 38 (70%) patients, most frequently infections (56%), ejection fraction reduction (11%), and diarrhea or nausea/vomiting (9% each). The combination of midostaurin and AZA is an effective and safe regimen in patients with AML and high‐risk MDS. Patients with FLT3 mutations but not previously exposed to other FLT3 inhibitors and patients not previously transplanted derived the greatest benefit. Further studies with this combination are warranted. Am. J. Hematol. 90:276–281, 2015. © 2014 Wiley Periodicals, Inc.
Phenylthiocarbamide taste sensitivity is associated with sinonasal symptoms in healthy adults
Authors: Farquhar Douglas R. , Kovatch Kevin J. , Palmer James N. , Shofer Frances S. , Adappa Nithin D. , Cohen Noam A.
Published: December 2014

Background

The bitter taste receptor T2R38, expressed in the tongue and nasal epithelium, has been shown to trigger sinonasal innate immunity contributing to the prevention of gram‐negative upper airway bacterial infections. Common polymorphisms of the T2R38 gene, correlating with bitter taste sensitivity to phenylthiocarbamide (PTC), have been linked to differences in sinonasal innate immune response, with specific genotypes significantly more common in medically recalcitrant chronic rhinosinusitis patients. The purpose of this study was to examine this association between T2R38 function and sinonasal infection or symptoms in a healthy population.

Methods

A survey of the frequency of sinus infections, as well as other nasal symptoms such as colds, allergies, and overall nasal quality of life (nQOL), was administered to healthy adult participants. nQOL was measured using a 0 to 3 scale of worsening symptoms. A PTC compound taste strip was administered with T2R38 taste sensitivity classified as extremely, somewhat, or not sensitive.

Results

Among 217 participants (55% female, 70% Caucasian, 42% age 21 to 25 years), 30% did not detect bitterness (nontasters), 34% were moderate tasters, and 36% were “supertasters,” experiencing a strong, unpalatable bitterness. Supertasters were associated with less frequent sinus infections (p = 0.04), and PTC sensitivity was predictive of nasal symptoms: Supertasters had the best nQOL scores, followed by moderate tasters and nontasters (means: 0.65, 0.81, 1.00, respectively; p = 0.014 for trend). There were no significant associations with other variables.

Conclusion

This study provides evidence that T2R38 functionality in the tongue correlates with nasal symptoms in healthy individuals.
Update on endoscopic endonasal resection of skull base meningiomas
Authors: Brunworth Joseph , Padhye Vikram , Bassiouni Ahmed , Psaltis Alkis , Floreani Stephen , Robinson Simon , Santoreneos Stephen , Vrodos Nick , Parker Andrew , Wickremesekera Agadha , Wormald Peter‐John
Published: December 2014

Background

The objective of this work was to report success rates as well as potential obstacles in transnasal endoscopic resection of anterior skull base meningiomas.

Methods

The study design was a case series with chart review at tertiary referral centers in South Australia and New Zealand. The patients were 37 consecutive patients who underwent endoscopic resection of skull‐base meningiomas between 2004 and 2013. Review of patient charts and operative details were performed. Outcomes including complications are reported.

Results

Eighty‐four percent of patients were women. There were 28 primary and 9 revision cases. Tumor locations were as follows: 14 olfactory groove/subfrontal; 12 planum/jugum sphenoidale; 7 tuberculum sellae; 3 clinoidal; and 1 clival. Vision change was the most common presenting symptom. Mean tumor volume was 33.68 cm3, mean diameter was 2.78 cm. Average operating times decreased with an initial learning curve and then plateaued. Primary tumors larger than 60 cm3 took an average of 10 hours to resect. Gross total removal was achieved in 29 patients. There were no perioperative deaths. Two deaths occurred within 1 year of surgery. Postoperative cerebrospinal fluid (CSF) leaks occurred in 13 patients. Seventy‐five percent of patients presenting with visual loss reported visual improvement. Of the 29 patients considered to have had complete resection at surgery, one was found to have residual disease on a postoperative magnetic resonance imaging (MRI) and another one later developed radiological evidence of recurrence.

Conclusion

Using a 2‐team approach, meningiomas of the skull base were successfully removed via an intranasal endoscopic technique. Although complete resection is typically possible even with large tumors, the lengthy resection required time for tumors larger than 60 cm3 (diameter ≥4 cm) may obviate some of the advantages of this approach. The rate of postoperative CSF leak decreases when a synthetic dural substitute is added but does not approach zero.
Experimentelle und theoretische Untersuchungen zur katalytischen asymmetrischen 4π‐Elektrocyclisierung von N‐Heterocyclen
Authors: Raja Sadiya , Nakajima Masaki , Rueping Magnus
Published: December 2014

Die erste asymmetrische metallkatalysierte Nazarov‐Cyclisierung von N‐Heterocyclen wurde entwickelt. Die Verwendung eines chiralen Katalysators ermöglicht die enantioselektive Elektrocyclisierung unter milden Bedingungen, wobei die Produkte in guten Ausbeuten und mit exzellenten Selektivitäten erhalten werden. Mittels Dichtefunktionalrechnungen werden der Reaktionsmechanismus und die absolute Konfiguration der erhaltenen Produkte erklärt.