bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of Computational Methods to Supported Metal–Oxide Catalysis
Authors: Senftle Thomas P. , van Duin Adri C. T. , Janik Michael J.
Published: January 2014

Enhancing the design of supported metal–oxide catalysts, featuring metal particles dispersed on an oxide support, is essential for optimizing the performance of numerous industrial chemical processes. Advances in computational chemistry over the last few decades have had a great impact on design strategies for obtaining active, selective, and stable catalysts. This chapter outlines computational approaches for modeling metal–oxide catalytic systems at the atomic level, and reviews pertinent studies that exemplify these methods. Examples are chosen to emphasize both quantum-based methods [utilizing density functional theory (DFT) and ab initio thermodynamics] and classical force-field methods (utilizing the ReaxFF empirical potential). We discuss studies that use DFT to evaluate the relative energies of metal–oxide surface structures, studies that extend the formalism of DFT to non-zero temperature and pressure via ab initio thermodynamics, and finally studies that use the COMB and ReaxFF empirical force-fields in MD and MC simulations to investigate system dynamics and structure at large scales. Reviewing the application of these methods will provide the reader with a general understanding of how computational methods can be applied to atomistic studies of supported metal–oxide catalysts.
Conformational modulation of peptide secondary structures using β-aminobenzenesulfonic acid
Authors: Kale Sangram S. , Kunjir Shrikant M. , Gawade Rupesh L. , Puranik Vedavati G. , Rajamohanan P. R. , Sanjayan Gangadhar J.
Published: January 2014

This communication describes the influence of β-aminobenzenesulfonic acid (SAnt) on the conformational preferences of hetero foldamers.
High-performance supercapacitor electrodes based on hierarchical Ti@MnO2 nanowire arrays
Authors: Zhu Dongdong , Wang Yadong , Yuan Guoliang , Xia Hui
Published: January 2014

Hierarchical Ti@MnO2 nanowire arrays prepared using a facile method exhibit promising electrochemical performance as electrodes for supercapacitors.
Selective synthesis of copper gallium sulfide (CuGaS2) nanostructures of different sizes, crystal phases, and morphologies
Authors: Chang Shu-Hao , Chiu Bo-Cheng , Gao Tzu-Lun , Jheng Shao-Lou , Tuan Hsing-Yu
Published: January 2014

We report the selective synthesis of CuGaS2 nanostructures of different sizes (3.0–10.9 nm), phases (chalcopyrite and wurtzite) and morphologies (nanocrystals and nanowires) in hot-solvent synthesis.
Aggregation induced blue-shifted emission – the molecular picture from a QM/MM study
Authors: Wu Qunyan , Zhang Tian , Peng Qian , Wang Dong , Shuai Zhigang
Published: January 2014

Aggregation induced blue-shifted emission is a consequence of the restricted structural relaxation, excited-state planarization and freezing of low-frequency out-of-plane vibrations.
Supramolecular photochemistry of drugs in biomolecular environments
Authors: Monti Sandra , Manet Ilse
Published: January 2014

We illustrate how the interaction of drugs with proteins or DNA in supramolecular complexes can influence the reactions initiated by drug absorbed photons, evidencing the differences with respect to solution.
Differences between amyloid-β aggregation in solution and on the membrane: insights into elucidation of the mechanistic details of Alzheimer's disease
Authors: Kotler Samuel A. , Walsh Patrick , Brender Jeffrey R. , Ramamoorthy Ayyalusamy
Published: January 2014

The association of the amyloid-β (Aβ) peptide with cellular membranes is hypothesized to be the underlying phenomenon of neurotoxicity in Alzheimer's disease.
A new closed-vessel conductively heated digestion system: fostering plant analysis by inductively coupled plasma optical emission spectroscopy
Authors: Miranda Kelber , Pereira-Filho Edenir Rodrigues , Gomes Neto José Anchieta
Published: January 2014

A high-throughput, low cost and efficient device based on conductive heating and closed-vessels was developed and applied to plant digestion.
The ubiquitin system: an essential component to unlocking the secrets of malaria parasite biology
Authors: Hamilton Michael J. , Lee Michael , Le Roch Karine G.
Published: January 2014

Exploration of the ubiquitin system in eukaryotes has shown that the chemical modification of proteins by ubiquitin, known as ubiquitylation, is an incredibly important post-translational event that is crucial to numerous cellular processes. In this review, we highlight our current understanding of the ubiquitin system inPlasmodium.
Serum ferritin is an important inflammatory disease marker, as it is mainly a leakage product from damaged cells
Authors: Kell Douglas B. , Pretorius Etheresia
Published: January 2014

Serum ferritin is a widely used inflammatory biomarker but it is actually a marker of cell damage.
An efficient one-step condensation and activation strategy to synthesize porous carbons with optimal micropore sizes for highly selective CO2 adsorption
Authors: Wang Jiacheng , Liu Qian
Published: January 2014

A series of microporous carbons (MPCs) were successfully prepared by an efficient one-step condensation and activation strategy using commercially available dialdehyde and diamine as carbon sources.
Enhanced MRI relaxivity of aquated Gd3+ ions by carboxyphenylated water-dispersed graphene nanoribbons
Authors: Gizzatov Ayrat , Keshishian Vazrik , Guven Adem , Dimiev Ayrat M. , Qu Feifei , Muthupillai Raja , Decuzzi Paolo , Bryant Robert G. , Tour James M. , Wilson Lon J.
Published: January 2014

The present study demonstrates a new high-performance MRI contrast agent with r1 = 70 and r2 = 108 mM−1 s−1 for applications in T1- and T2-weighted imaging.
“Pure shift” 1H NMR, a robust method for revealing heteronuclear couplings in complex spectra
Authors: Aguilar Juan A. , Morris Gareth A. , Kenwright Alan M.
Published: January 2014

We investigate the utility of “pure shift” techniques in revealing heteronuclear couplings in complex 1H NMR spectra.
Electron deficient diketopyrrolopyrrole dyes for organic electronics: synthesis by direct arylation, optoelectronic characterization, and charge carrier mobility
Authors: Hendsbee Arthur D. , Sun Jon-Paul , Rutledge Lesley R. , Hill Ian G. , Welch Gregory C.
Published: January 2014

Four electron deficient small molecules based on the diketopyrrolopyrrole (DPP) chromophore were synthesized using microwave-assisted direct arylation reactivity.
Enhancement of mechanical stability in hydrogen-bonded photomobile materials with chemically modified single-walled carbon nanotubes
Authors: Ozawa Tetsuya , Kondo Mizuho , Mamiya Jun-ichi , Ikeda Tomiki
Published: January 2014

Hydrogen-bonded photomobile liquid-crystalline polymer fibers with chemically modified single-walled carbon nanotubes were prepared and their photomobile properties were investigated.
Enantioselective hydroacylation of N-vinylindole-2-carboxaldehydes
Authors: Ghosh Avipsa , Stanley Levi M.
Published: January 2014

We report rhodium-catalyzed hydroacylations of N-vinylindole-2-carboxaldehydes that form chiral, non-racemic 2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-ones in high yields with excellent enantioselectivities.
Initiator-free hydrocarbon oxidation using supported gold nanoparticles
Authors: Alshammari Hamed , Miedziak Peter J. , Davies Thomas E. , Willock David J. , Knight David W. , Hutchings Graham J.
Published: January 2014

In the catalytic oxidation of cycloalkenes and linear internal alkenes using oxygen radical initiators are not required if the stabilisers are removed prior to reaction.
Towards a facile and convenient synthesis of highly functionalized indole derivatives based on multi-component reactions
Authors: Neochoritis Constantinos G. , Dömling Alexander
Published: January 2014

A library of potentially bioactive compounds through the novel 1H-indole-methyl-isocyanide and MCRs has been described.
Ultrasensitive single crystalline TeO2 nanowire based hydrogen gas sensors
Authors: Yan Changzeng , Huy Le Binh , Kang Dae Joon
Published: January 2014

Successful application of TeO2 nanowires grown by thermal evaporation for hydrogen sensors exhibiting 28% sensitivity at room temperature.
New strategies to inhibit KEAP1 and the Cul3-based E3 ubiquitin ligases
Authors: Canning Peter , Bullock Alex N.
Published: January 2014

E3 ubiquitin ligases that direct substrate proteins to the ubiquitin–proteasome system are promising, though largely unexplored drug targets both because of their function and their remarkable specificity. CRLs [Cullin–RING (really interesting new gene) ligases] are the largest group of E3 ligases and function as modular multisubunit complexes constructed around a Cullin-family scaffold protein. The Cul3-based CRLs uniquely assemble with BTB (broad complex/tramtrack/bric-à-brac) proteins that also homodimerize and perform the role of both the Cullin adapter and the substrate-recognition component of the E3. The most prominent member is the BTB–BACK (BTB and C-terminal Kelch)–Kelch protein KEAP1 (Kelch-like ECH-associated protein 1), a master regulator of the oxidative stress response and a potential drug target for common conditions such as diabetes, Alzheimer's disease and Parkinson's disease. Structural characterization of BTB–Cul3 complexes has revealed a number of critical assembly mechanisms, including the binding of an N-terminal Cullin extension to a bihelical ‘3-box’ at the C-terminus of the BTB domain. Improved understanding of the structure of these complexes should contribute significantly to the effort to develop novel therapeutics targeted to CRL3-regulated pathways.
Structures of soluble guanylate cyclase: implications for regulatory mechanisms and drug development
Authors: Gileadi Opher
Published: January 2014

Activation of cGMP synthesis leads to vasodilation, and is an important mechanism in clinical treatment of angina, heart failure, and severe peripheral and pulmonary hypertension. The nitric oxide-responsive sGC (soluble guanylate cyclase) has been the target of recent drug discovery efforts. The present review surveys recent data on the structure and regulation of sGC, and the prospects of new avenues for therapeutic intervention.
Measurement of beam characteristics from C6+ laser ion source
Authors: Yamaguchi A. , Sako K. , Sato K. , Hayashizaki N. , Hattori T.
Published: January 2014

We developed a C6+ laser ion source for a heavy-ion accelerator. A carbon target was irradiated with a Q-switched Nd:YAG laser (1064 nm wavelength, 1.4 J maximum laser energy, 10 ns pulse duration) to generate a high-density plasma. The laser ion source employed a rotating carbon target for continuous operation. Ion beams were extracted from the plasma through a drift space using a direct plasma injection scheme [B. Yu. Sharkov, A. V. Shumshurov, V. P. Dubenkow, O. B. Shamaev, and A. A. Golubev, Rev. Sci. Instrum. 63, 2841 (1992)] up to a maximum voltage of 40 kV. We measured the characteristics of the ion beams from the laser ion source and present the results of experiments here.
A universal setup for active control of a single-photon detector
Authors: Liu Qin , Lamas-Linares Antía , Kurtsiefer Christian , Skaar Johannes , Makarov Vadim , Gerhardt Ilja
Published: January 2014

The influence of bright light on a single-photon detector has been described in a number of recent publications. The impact on quantum key distribution (QKD) is important, and several hacking experiments have been tailored to fully control single-photon detectors. Special attention has been given to avoid introducing further errors into a QKD system. We describe the design and technical details of an apparatus which allows to attack a quantum-cryptographic connection. This device is capable of controlling free-space and fiber-based systems and of minimizing unwanted clicks in the system. With different control diagrams, we are able to achieve a different level of control. The control was initially targeted to the systems using BB84 protocol, with polarization encoding and basis switching using beamsplitters, but could be extended to other types of systems. We further outline how to characterize the quality of active control of single-photon detectors.
X-ray spectroscopy of warm and hot electron components in the CAPRICE source plasma at EIS testbench at GSI
Authors: Mascali D. , Celona L. , Maimone F. , Maeder J. , Castro G. , Romano F. P. , Musumarra A. , Altana C. , Caliri C. , Torrisi G. , Neri L. , Gammino S. , Tinschert K. , Spaedtke K. P. , Rossbach J. , Lang R. , Ciavola G.
Published: January 2014

An experimental campaign aiming to detect X radiation emitted by the plasma of the CAPRICE source – operating at GSI, Darmstadt – has been carried out. Two different detectors (a SDD – Silicon Drift Detector and a HpGe – hyper-pure Germanium detector) have been used to characterize the warm (2–30 keV) and hot (30–500 keV) electrons in the plasma, collecting the emission intensity and the energy spectra for different pumping wave frequencies and then correlating them with the CSD of the extracted beam measured by means of a bending magnet. A plasma emissivity model has been used to extract the plasma density along the cone of sight of the SDD and HpGe detectors, which have been placed beyond specific collimators developed on purpose. Results show that the tuning of the pumping frequency considerably modifies the plasma density especially in the warm electron population domain, which is the component responsible for ionization processes: a strong variation of the plasma density near axis region has been detected. Potential correlations with the charge state distribution in the plasma are explored.
On the nature of long range electronic coupling in a medium: Distance and orientational dependence for chromophores in molecular aggregates
Authors: Lock Maximilian P. E. , Andrews David L. , Jones Garth A.
Published: January 2014

The electronic coupling that mediates energy transfer in molecular aggregates is theoretically investigated using the principles of quantum electrodynamics (QED). In this context, both the electromagnetic tensor and rate equation relating to these couplings are re-examined with a focus on the role of the relative distance and orientation of transition dipole moment pairs, considering near-, intermediate-, and far-zone contributions to the coupling. The QED based coupling terms are investigated both analytically and numerically, and they are physically interpreted in terms of the character of the mediating (virtual) photons. The spatial dependence of the couplings for a two-dimensional molecular aggregate of ordered and isotropic transition dipole moments is numerically calculated. Further, Pauli Master Equations are employed for a one-dimensional chain of molecules and donor-acceptor pairs, to investigate the importance of intermediate- and far-zone contributions to the electronic coupling on electronic energy transfer dynamics. The results indicate that although Förster theory is often qualitatively and quantitatively correct for describing electronic energy transfer (EET) processes, intermediate- and far-zone coupling terms could sometimes be non-negligible for correctly describing EET in natural and artificial, mesoscopic, solar energy harvesting systems. In particular, the results indicate that these terms are non-negligible when using Förster resonance energy transfer spectroscopic ruler techniques for distances >10 nm.
Comparison of classical and quantal calculations of helium three-body recombination
Authors: Pérez-Ríos Jesús , Ragole Steve , Wang Jia , Greene Chris H.
Published: January 2014

A general method to study classical scattering in n-dimension is developed. Through classical trajectory calculations, the three-body recombination is computed as a function of the collision energy for helium atoms, as an example. Quantum calculations are also performed for the JΠ = 0+ symmetry of the three-body recombination rate in order to compare with the classical results, yielding good agreement for E ≳ 1 K. The classical threshold law is derived and numerically confirmed for the Newtonian three-body recombination rate. Finally, a relationship is found between the quantum and classical three-body hard hypersphere elastic cross sections which is analogous to the well-known shadow scattering in two-body collisions.
Exciton dissociation at donor-acceptor heterojunctions: Dynamics using the collective effective mode representation of the spin-boson model
Authors: Chenel Aurélie , Mangaud Etienne , Burghardt Irene , Meier Christoph , Desouter-Lecomte Michèle
Published: January 2014

Following the recent quantum dynamics investigation of the charge transfer at an oligothiophene-fullerene heterojunction by the multi-configuration time dependent Hartree method [H. Tamura, R. Martinazzo, M. Ruckenbauer and I. Burghardt, J. Chem. Phys. 137, 22A540 (2012)], we revisit the transfer process by a perturbative non-Markovian master equation treated by the time local auxiliary density matrix approach. We compare the efficiency of the spin-boson model calibrated by quantum chemistry with the effective mode representation. A collective mode is extracted from the spin-boson spectral density. It is weakly coupled to a residual bath of vibrational modes, allowing second-order dynamics. The electron transfer is analyzed for a sampling of inter-fragment distances showing the fine interplay of the electronic coupling and energy gap on the relaxation. The electronic coherence, expected to play a role in the process, is preserved during about 200 fs.
Data mining for materials design: A computational study of single molecule magnet
Authors: Dam Hieu Chi , Pham Tien Lam , Ho Tu Bao , Nguyen Anh Tuan , Nguyen Viet Cuong
Published: January 2014

We develop a method that combines data mining and first principles calculation to guide the designing of distorted cubane Mn4 +\documentclass[12pt]{minimal}\begin{document}${\rm Mn}^{3+}_3$\end{document} Mn 33+ single molecule magnets. The essential idea of the method is a process consisting of sparse regressions and cross-validation for analyzing calculated data of the materials. The method allows us to demonstrate that the exchange coupling between Mn4 + and Mn3 + ions can be predicted from the electronegativities of constituent ligands and the structural features of the molecule by a linear regression model with high accuracy. The relations between the structural features and magnetic properties of the materials are quantitatively and consistently evaluated and presented by a graph. We also discuss the properties of the materials and guide the material design basing on the obtained results.
Formation and anisotropic magnetoresistance of Co/Pt nano-contacts through aluminum oxide barrier
Authors: Al-Mahdawi Muftah , Sahashi Masashi
Published: January 2014

We report on the observation of anisotropic magnetoresistance (AMR) in vertical asymmetric nano-contacts (NCs) made through AlOx nano-oxide layer (NOL) formed by ion-assisted oxidation method in the film stack of Co/AlOx-NOL/Pt. Analysis of NC formation was based on in situ conductive atomic force microscopy and transmission electron microscopy. Depending on the purity of NCs from Al contamination, we observed up to 29% AMR ratio at room temperature.
High-pressure x-ray diffraction study of YBO3/Eu3+, GdBO3, and EuBO3: Pressure-induced amorphization in GdBO3
Authors: Wang Pei , He Duanwei , Xu Chao , Ren Xiangting , Lei Li , Wang Shanmin , Peng Fang , Yan Xiaozhi , Liu Dongqiong , Wang Qiming , Xiong Lun , Liu Jing
Published: January 2014

Angle-dispersive synchrotron X-ray diffraction measurements were performed on vaterite-type YBO3/Eu3+, GdBO3, and EuBO3, respectively, up to 41 GPa at room temperature using a diamond-anvil cell. Pressure-induced amorphization was observed in hexagonal GdBO3 with a significant compression along the c-axis. Compared to the ions of the distorted GdBO3 phase, its anions may lose their long-range order prior to the cations at high pressures. Based on the experimental pressure-volume data, the obtained bulk moduli of YBO3/Eu3+ and GdBO3 are 329 and 321 GPa, respectively, which are more than 90% larger than that of EuBO3 (167 GPa) and are presumably attributed to Gd3+ and Y3+ with a high density of d valence electrons.
Transition-metal and metalloid substitutions in L10-ordered FeNi
Authors: Manchanda Priyanka , Skomski Ralph , Bordeaux N. , Lewis L. H. , Kashyap Arti
Published: January 2014

The effect of atomic substitutions on the magnetization, exchange, and magnetocrystalline anisotropy energy of L10-ordered FeNi (tetrataenite) is computationally investigated. The compound naturally occurs in meteorites but has attracted renewed attention as a potential material for permanent magnets, and elemental additives will likely be necessary to facilitate the phase formation. Our density functional theory calculations use the Vienna ab-initio simulation package, applied to 4-atom unit cells of Fe2XNi and 32-atom supercells (X = Al, P, S, Ti, V, Cr, Mn, Fe, Co). While it is found that most additives deteriorate the magnetic properties, there are exceptions: excess substitutional Fe and Co additions improve the magnetization, whereas Cr, S, and interstitial B additions improve the magnetocrystalline anisotropy.
Hysteretic behavior of Fe(phen)2(NCS)2 spin-transition microparticles vs. the environment: A huge reversible component resolved by first order reversal curves
Authors: Tanasa Radu , Laisney Jérôme , Stancu Alexandru , Boillot Marie-Laure , Enachescu Cristian
Published: January 2014

We discuss the influence of the embedding matrix on the thermal hysteretic behavior of spin transition microparticles of Fe(phen)2(NCS)2 by using a series of experimental first order reversal curves (FORCs). The shape of FORCs supports the hypothesis considering additional interactions between the spin-transition microparticles and the embedding matrix, which compares to a negative pressure on the particles. A mean-field approach based on negative variable external pressures, together with a cut off/switch on of particles-matrix interactions accounts for the experimental features.
Antenna-coupled microcavities for enhanced infrared photo-detection
Authors: Nga Chen Yuk , Todorov Yanko , Askenazi Benjamin , Vasanelli Angela , Biasiol Giorgio , Colombelli Raffaele , Sirtori Carlo
Published: January 2014

We demonstrate mid-infrared detectors embedded into an array of double-metal nano-antennas. The antennas act as microcavities that squeeze the electric field into thin semiconductor layers, thus enhancing the detector responsivity. Furthermore, thanks to the ability of the antennas to gather photons from an area larger than the device's physical dimensions, the dark current is reduced without hindering the photo-generation rate. In these devices, the background-limited performance is improved with a consequent increase of the operating temperature. Our results illustrate how the antenna-coupled microcavity concept can be applied to enhance the performances of infrared opto-electronic devices.
Crystallographically anisotropic Sm2Fe17Nδ and Nd(Fe,Mo)12Nx hard magnetic flakes
Authors: Cui B. Z. , Marinescu M. , Liu J. F.
Published: January 2014

This paper reports the morphology, structure, and magnetic properties of Sm2Fe17Nδ and Nd(Fe,Mo)12Nx anisotropic flakes prepared by surfactant–assisted high energy ball milling (HEBM). Sm14Fe86Nδ jet milled microparticles with a size of 1–2.5 μm and NdFe10.5Mo1.5Nx nitride crushed microparticles with a size of 1–80 μm were subjected to HEBM in heptane with 10 or 20 wt. % oleic acid. As the milling time increased, first, single-crystal, and then [001] textured poly-nanocrystalline nitride flakes with micron, submicron, or nanosized thicknesses were synthesized. The intrinsic coercivity, Hci, of Sm14Fe86Nδ flakes initially increases and reaches a maximum value of 12.3 kOe upon milling for 3 h, at which point the thickness becomes less than 250 nm and the length is 1–4 μm. A maximum Hci value of 8.7 kOe for NdFe10.5Mo1.5Nx flakes was obtained after milling for 12 h, with the thickness less than 100 nm and the length 1–16 μm. Anisotropic magnetic behavior was observed for all of the nitride flakes.
Magnetic configuration dependence of magnetoresistance in a Fe-porphyrin-like carbon nanotube spintronic device
Authors: Zeng Jing , Chen Ke-Qiu
Published: January 2014

By using nonequilibrium Green's functions in combination with the density functional theory, we investigate the spin-dependent transport properties in a Fe-porphyrin-like carbon nanotube spintronic device. The results show that magnetoresistance ratio is strongly dependent on the magnetic configuration of the Fe-porphyrin-like carbon nanotube. Under the application of the external magnetic field, the magnetoresistance ratio of the device can be increased from about 19% to about 1020% by tuning the magnetic configuration in the device. Our results confirm that the magnetic configuration is a key factor for obtaining a high-performance spintronic device.
Experimental study on the emission spectra of microwave plasma at atmospheric pressure
Authors: Zhang Boya , Wang Qiang , Zhang Guixin , Liao Shanshan
Published: January 2014

An experimental study on microwave plasma at atmospheric pressure was conducted by employing optical emission spectroscopy. Based on a microwave plasma generation device developed for nanoparticle synthesis, we studied the influence of input microwave power and gas flow rate on the optical emission behaviors and electron temperature of plasma using Ar, He, and N2 as working gas, respectively. The physics behind these behaviors was discussed. The results are useful in characterizing microwave plasma at atmospheric pressure and can be used for improving nanoparticle synthesis system for commercial use in the future.
Analysing organic transistors based on interface approximation
Authors: Akiyama Yuto , Mori Takehiko
Published: January 2014

Temperature-dependent characteristics of organic transistors are analysed thoroughly using interface approximation. In contrast to amorphous silicon transistors, it is characteristic of organic transistors that the accumulation layer is concentrated on the first monolayer, and it is appropriate to consider interface charge rather than band bending. On the basis of this model, observed characteristics of hexamethylenetetrathiafulvalene (HMTTF) and dibenzotetrathiafulvalene (DBTTF) transistors with various surface treatments are analysed, and the trap distribution is extracted. In turn, starting from a simple exponential distribution, we can reproduce the temperature-dependent transistor characteristics as well as the gate voltage dependence of the activation energy, so we can investigate various aspects of organic transistors self-consistently under the interface approximation. Small deviation from such an ideal transistor operation is discussed assuming the presence of an energetically discrete trap level, which leads to a hump in the transfer characteristics. The contact resistance is estimated by measuring the transfer characteristics up to the linear region.
Calculation of self-diffusion coefficients in iron
Authors: Zhang Baohua
Published: January 2014

On the basis of available P-V-T equation of state of iron, the temperature and pressure dependence of self-diffusion coefficients in iron polymorphs (α, δ, γ and ɛ phases) have been successfully reproduced in terms of the bulk elastic and expansivity data by means of a thermodynamical model that interconnects point defects parameters with bulk properties. The calculated diffusion parameters, such as self-diffusion coefficient, activation energy and activation volume over a broad temperature range (500-2500 K) and pressure range (0-100 GPa), compare favorably well with experimental or theoretical ones when the uncertainties are considered.
Youth on Streets and Bob-a-Job Week: Urban Geographies of Masculinity, Risk, and Home in Postwar Britain
Authors: Mills Sarah
Published: January 2014

After World War Two, youth in Britain was constructed as unruly, troublesome, and deviant, particularly in public urban space and streets. However, not all children and young people were discouraged from entering these environments or engaging with the general public. Drawing from literature published by the Boy Scout Association and a case study of Bob-a-Job Week in Britain launched in 1949, I examine the institutional geographies of responsibility, risk, and reward embedded in this youth activity, orchestrated by the most popular youth organisation in Britain. This fundraising scheme involved Boy Scouts completing domestic tasks for householders and encouraged uniformed youth to be visible, proficient, and useful. Significantly, this also took place in largely urban areas—complicating our understanding of scouting as an idealised ‘rural’ practice with camping as its central activity. Furthermore, this paper explores how this fundraising spectacle also functioned as a hybrid space that permitted ‘feminine’ domestic tasks as appropriate for ‘British boyhood’ until the scheme's eventual demise in the 1990s. Overall, the complex geographies of Bob-a-Job Week reveal how this organisation negotiated the boundaries between domestic and public space, providing an insight into broader constructions of youth and gender in the postwar period.
How Technological Change Affects Power Relations in Global Markets: Remote Developers in the Console and Mobile Games Industry
Authors: Parker Rachel , Cox Stephen , Thompson Paul
Published: January 2014

This paper focuses on Australian development firms in the console and mobile games industry in order to understand how small firms in a geographically remote and marginal position in the global industry are able to relate to global firms and capture revenue share. This paper shows that, while technological change in the games industry has resulted in the emergence of new industry segments based on transactional rather than relational forms of economic coordination, in which we might therefore expect less asymmetrical power relations, lead firms retain a position of power in the global games entertainment industry relative to remote developers. This has been possible because lead firms in the emerging mobile devices market have developed and sustained bottlenecks in their segment of the industry through platform competition and the development of an intensely competitive ecosystem of developers. Our research shows the critical role of platform competition and bottlenecks in influencing power asymmetries within global markets.
Affect, Consumption, and Identity at a Buenos Aires Shopping Mall
Authors: Miller Jacob C
Published: January 2014

This paper explores the built environment of a shopping mall in light of recent theoretical interventions that stress the affective dimensions of everyday political life. By drawing on sixteen weeks of ethnographic fieldwork at a shopping mall in central Buenos Aires, Argentina, I explore how retail affects are unevenly distributed across a diverse public, and how different bodies, in turn, affect the mall in particular ways. In short, this paper explores embodiment as an affective experience that coheres around raced, classed, and gendered bodies at the mall. As such, this paper helps clarify how ethnographic research can benefit from nonrepresentational theory and the ‘new materialism’ literature that challenges prevailing conceptual approaches to the politics of consumption.
Combined TRPC3 and TRPC6 blockade by selective small-molecule or genetic deletion inhibits pathological cardiac hypertrophy
Authors: Seo Kinya , Rainer Peter P. , Shalkey Hahn Virginia , Lee Dong-ik , Jo Su-Hyun , Andersen Asger , Liu Ting , Xu Xiaoping , Willette Robert N. , Lepore John J. , Marino Joseph P. , Birnbaumer Lutz , Schnackenberg Christine G. , Kass David A.
Published: January 2014

Significance

Cardiac hypertrophy and dysfunction in response to sustained hormonal and mechanical stress are sentinel features of most forms of heart disease. Activation of non–voltage-gated transient receptor potential canonical channels TRPC3 and TRPC6 may contribute to this pathophysiology and provide a therapeutic target. Effects from combined selective inhibition have not been tested previously. Here we report the capability of highly selective TRPC3/6 inhibitors to block pathological hypertrophic signaling in several cell types, including adult cardiac myocytes. We show in vivo redundancy of each channel; individual gene deletion was not protective against sustained pressure overload, whereas combined deletion ameliorated the response. These data strongly support a role for both channels in cardiac disease and the utility of selective combined inhibition.
The double-stranded transcriptome of
Escherichia coli
Authors: Lybecker Meghan , Zimmermann Bob , Bilusic Ivana , Tukhtubaeva Nadezda , Schroeder Renée
Published: January 2014

Significance

One of the most highly debated questions in the field of transcriptomics is the functionality of antisense transcripts. Are these transcripts merely transcriptional noise and a byproduct of the leakiness of transcriptional repression, or are they functional? Antisense RNAs are being ubiquitously reported, but their functionality remains elusive. Here we report a high-throughput approach to enrich antisense RNAs that are in a double-stranded form with their cognate sense RNAs and thus in a functional complex. This has led to the identification of more than 300 RNase III-dependent potentially functional antisense RNAs in
Escherichia coli
. These findings reveal a clear picture of the magnitude and degree of functionality of this mostly hidden class of transcripts.
A Review of Urban Water Body Challenges and Approaches: (1) Rehabilitation and Remediation
Authors: Hughes Robert M , Dunham Susie , Maas-Hebner Kathleen G , Yeakley J Alan , Schreck Carl , Harte Michael , Molina Nancy , Shock Clinton C , Kaczynski Victor W , Schaeffer Jeff
Published: January 2014

We review how urbanization alters aquatic ecosystems, as well as actions that managers can take to remediate urban waters. Urbanization affects streams by fundamentally altering longitudinal and lateral processes that in turn alter hydrology, habitat, and water chemistry; these effects create physical and chemical stressors that in turn affect the biota. Urban streams often suffer from multiple stressor effects that have collectively been termed an “urban stream syndrome,” in which no single factor dominates degraded conditions. Resource managers have multiple ways of combating the urban stream syndrome. These approaches range from whole-watershed protection to reach-scale habitat rehabilitation, but the prescription must be matched to the scale of the factors that are causing the problem, and results will likely not be immediate because of lengthy recovery times. Although pristine or reference conditions are far from attainable, urban stream rehabilitation is a worthy goal because appropriate actions can provide ecosystem improvements as well as increased ecosystem service benefits for human society.

RESUMEN

se hace una revisión de cómo la urbanización altera los ecosistemas acuáticos, así como también de las acciones que los administradores pueden tomar para remediar el problema de las aguas urbanas. La urbanización afecta los ríos a través de la alteración de procesos longitudinales y laterales que, a su vez, modifican la hidrología, hábitat y química del agua; estos efectos crean factores químicos y físicos de estrés que perturban la biota. Los ríos urbanos suelen estar sujetos a múltiples factores de estrés que colectivamente se conocen como “síndrome del río urbano” en el cual no existe dominancia de un solo factor de degradación. Los administradores de recursos naturales tienen diversas formas de combatir este síndrome. Estos enfoques van desde protección de cuencas enteras hasta rehabilitación de hábitats a gran escala, pero la prescripción debe ser consistente con la escala de los factores que están causando el problema, y es probable que los resultados no sean inmediatos dado que los tiempos de recuperación son prolongados. A pesar de que se está lejos de poder reconstruir las condiciones prístinas o de referencia, la rehabilitación de los ríos urbanos es un objetivo digno de perseguir ya que la toma de acciones adecuadas pueden lograr mejoras a los ecosistemas así como también un incremento en los beneficios que la sociedad humana obtiene de ellos.
Building spiritual capabilities to sustain sustainability-based competitive advantages
Authors: Stead Jean Garner , Stead W. Edward
Published: January 2014

There is a rising global concern that centers on creating an ecologically, socially, and economically sustainable world for current and future generations. This rising sustainability consciousness is built on higher-level value systems that support the sacredness of people and nature. These values promote environmental and social responsibility as avenues to fair profits, and they are currently penetrating the global business environment. Because of their coevolutionary relationships with the business environment, business organizations are now faced with the need to craft efficient and effective triple bottom line strategies that allows them to earn profits in sustainable ways. Because sustainability is complex, multifaceted concept with deep spiritual roots, building triple bottom line strategies requires that organizations develop intangible spiritual capabilities (i.e. spiritual intelligence and spiritual capital) that are valuable, rare, holistic, socially complex, and causally ambiguous, making them difficult to imitate.
Psychometric Evaluation of the Dutch Version of the Impulsive/Premeditated Aggression Scale (IPAS) in Male and Female Prisoners
Authors: Kuyck WouterG. E. , de Beurs Edwin , Barendregt Marko , van den Brink Wim
Published: January 2014

Aggressive behavior is traditionally classified into two subtypes, impulsive and premeditated aggression. The Impulsive/Premeditated Aggression Scale (IPAS) is a self-report questionnaire to measure a person's tendency towards these subtypes of aggressive behavior. This study reports on the psychometric quality of the Dutch translation of the IPAS in a sample of 149 male and 70 female prisoners in the Netherlands. Confirmatory Factor Analysis yielded two factors with an item composition quite similar to those found in previous studies: impulsive aggression, 17 items; premeditated aggression, 13 items. For both factors reliable subscales could be composed for males and females: impulsive aggression αmales = .92, αfemales = .94; premeditated aggression αmales = .90 and αfemales = .91. The subscales were highly correlated: r males = .70, r females = .75. It is concluded that the underlying structure of the Dutch version of the IPAS is similar to the original version of the questionnaire, that internal consistency of the two subscales is good, and that the correlation between the two subscales is higher than previously reported. Possible reasons for the high correlation of the subscales are discussed. Additional studies are needed to establish the construct and criterion/predictive validity of the IPAS in the forensic field.
Non-Suicidal Self-Injury in Women Offenders: Motivations, Emotions, and Precipitating Events
Authors: Power Jenelle , Brown ShelleyL. , Usher AmeliaM.
Published: January 2014

Non-suicidal self-injury (NSSI) poses a serious threat to the safety and well-being of offenders and staff, making it a critical issue for correctional institutions, yet little is known about NSSI adult women offenders. Fifty-six women residing in Canadian federal correctional institutions with a history of NSSI participated in semi-structured interviews to explore their behavior. More than two-thirds of the women interviewed reported engaging in NSSI as a method of coping with negative emotions. The most common emotions reported prior to engaging in NSSI were anger, depression, and anxiety. The most common event that preceded NSSI was interpersonal conflict. After self-injuring, women most commonly reported feelings of relief, followed by regret. Whereas many women described similar experiences with NSSI, this research suggests that NSSI is a complex behavior with many different motivations and precipitating factors, and that effective treatment should consider the individual's unique needs.
Pumping Performance of a Modified Commercial Paddlewheel Aerator for Split-Pond Aquaculture Systems
Authors: Brown Travis W , Tucker Craig S
Published: January 2014

The split-pond aquaculture system consists of a small fish holding basin that is connected to a waste treatment lagoon by two conduits. Split ponds require large water volumes circulated between the two basins (10,000–20,000 gal/min for 5–10-acre ponds) to remove fish waste and provide oxygenated water to the fish. Farmers producing ictalurid catfish in the USA have rapidly adopted this new technology to improve production efficiency. The original split-pond design used large, slow-rotating paddlewheels to circulate water; in this study, we evaluated paddlewheel aerators as pumps for split ponds. Pumping performance was evaluated at rotational speeds of 25–66 rotations/min and paddle submergence depths of 4.0, 6.8, and 9.5 in. Water flow rates ranged from 8,240 to 25,069 gal/min. Flows increased with increasing rotational speed and paddle submergence depth. Power input varied directly with flow rate and ranged from 1.08 to 8.28 hp. Water discharge per unit power input (i.e., pumping efficiency) ranged from 3,026 to 10,824 gal·min−1·hp−1; pumping efficiency decreased as water flow rate increased and as paddle submergence depth decreased. Placement of the paddlewheel at the channel inlet (with water being pushed through the channel) produced flow rates three times greater than placement at the outlet (with water being pulled through the channel). Our results show that commercial paddlewheel aerators can be modified, operated, and located to provide the water flows needed in commercial-sized split ponds. Although they are more expensive to operate than slow-rotating paddlewheels (which are specifically designed as water pumps), paddlewheel aerators offer the advantages of lower investment cost, greater availability, and easy maintenance. Long-term studies are underway to compare operational issues and costs associated with the use of various pump types, including paddlewheel aerators, in split-pond aquaculture.
Reading in Spanish and Italian: Effects of Age of Acquisition in Transparent Orthographies?
Authors: Davies Rob , Wilson Maximiliano , Cuetos Fernando , Burani Cristina
Published: January 2014

Despite the similar transparency of their orthographies, reading in Italian has been found to be affected by frequency but not age of acquisition (AoA) [Barca, L., Burani, C., & Arduino, L. S. (2002). Word naming times and psycholinguistic norms for Italian nouns. Behaviour Research Methods, Instruments and Computers, 34, 424–434] while reading in Spanish is affected by AoA but not frequency [Cuetos, F., & Barbón, A. (2006). Word naming in Spanish. European Journal of Cognitive Psychology, 18, 415–436]. We examined this cross-linguistic difference, firstly, through a reanalysis of the Italian and Spanish reading latencies. After eliminating several between-experiment differences, we replicated the AoA effect in Spanish but not in Italian and the frequency effect in Italian but not in Spanish. The cross-linguistic comparison could not equate stimulus imageability; therefore, secondly, we compared the Italian reading latencies with new Spanish reading latencies for imageability-matched words. We found frequency effects but neither an AoA effect nor a language by AoA interaction. We argue that the previously reported cross-linguistic difference in the AoA effect resulted from a between-study difference in stimulus imageability. More imageable words induced more semantic involvement in reading, yielding an AoA effect in Spanish.
The cost of a gelatinous future and loss of critical habitats in the Mediterranean
Authors: Kontogianni A. D. , Emmanouilides C. J.
Published: January 2014

This paper investigates the economic valuations individuals make about the degradation of the marine ecosystem in the Gulf of Lion, in the western Mediterranean. A choice experiment has been conducted to quantify in monetary terms the social costs associated with two key aspects of degradation of the marine ecosystem: (i) the loss of critical habitats, and (ii) the risk of jellyfish outbreaks. We apply choice models to analyse the preference structure of residents and visitors for alternative ecosystem resilience scenarios. The focus of the modelling approach is on inference about welfare valuations and their relationship to the characteristics of the participants in the choice experiment, their perceptions of the importance of ecosystem services, attitudes to tourism, and trust in environmental policy-making institutions. We detected a number of significant linear and non-linear effects, and discuss the implications of our findings for marine environment protection policies.
Stepwise assembly of multiple Lin28 proteins on the terminal loop of let-7 miRNA precursors
Authors: Desjardins Alexandre , Bouvette Jonathan , Legault Pascale
Published: January 2014

Lin28 inhibits the biogenesis of let-7 miRNAs through direct interactions with let-7 precursors. Previous studies have described seemingly inconsistent Lin28 binding sites on pre-let-7 RNAs. Here, we reconcile these data by examining the binding mechanism of Lin28 to the terminal loop of pre-let-7g (TL-let-7g) using biochemical and biophysical methods. First, we investigate Lin28 binding to TL-let-7g variants and short RNA fragments and identify three independent binding sites for Lin28 on TL-let-7g. We then determine that Lin28 assembles in a stepwise manner on TL-let-7g to form a stable 1:3 complex. We show that the cold-shock domain (CSD) of Lin28 is responsible for remodelling the terminal loop of TL-let-7g, whereas the NCp7-like domain facilitates the initial binding of Lin28 to TL-let-7g. This stable binding of multiple Lin28 molecules to the terminal loop of pre-let-7g extends to other precursors of the let-7 family, but not to other pre-miRNAs tested. We propose a model for stepwise assembly of the 1:1, 1:2 and 1:3 pre-let-7g/Lin28 complexes. Stepwise multimerization of Lin28 on pre-let-7 is required for maximum inhibition of Dicer cleavage for a least one member of the let-7 family and may be important for orchestrating the activity of the several factors that regulate let-7 biogenesis.
Folding a stable RNA pseudoknot through rearrangement of two hairpin structures
Authors: Wu Yi-Ju , Wu Cheng-Han , Yeh Athena Yi-Chun , Wen Jin-Der
Published: January 2014

Folding messenger RNA into specific structures is a common regulatory mechanism involved in translation. In Escherichia coli, the operator of the rpsO gene transcript folds into a pseudoknot or double-hairpin conformation. S15, the gene product, binds only to the pseudoknot, thereby repressing its own synthesis when it is present in excess in the cell. The two RNA conformations have been proposed to exist in equilibrium. However, it remained unclear how structural changes can be achieved between these two topologically distinct conformations. We used optical tweezers to study the structural dynamics and rearrangements of the rpsO operator RNA at the single-molecule level. We discovered that the two RNA structures can be interchanged spontaneously and the pseudoknot can exist in conformations that exhibit various levels of stability. Conversion from the double hairpin to a pseudoknot through potential hairpin–hairpin interactions favoured the high-stability conformation. By contrast, mutations that blocked the formation of a hairpin typically resulted in alternative low-stability pseudoknots. These results demonstrate that specific tertiary interactions of RNA can be established and modulated based on the interactions and rearrangements between secondary structural components. Our findings provide new insight into the RNA folding pathway that leads to a regulatory conformation for target protein binding.