bluuebunny/crossref_metadata_2025 huggingface dataset:
The End of Sophocles' Oedipus Tyrannus: The Sceptical Case Restated
Authors: Kovacs David
Published: December 2014

An earlier article of mine, Kovacs (2009a), discussed OT 1424–1530, whose genuineness was impugned most recently by Dawe (2001; 2006). I argued that 1424–67 (which I call A) are genuine, but that 1468–1530 (which I call B) are spurious. Sommerstein (2011), accepting my defence of A, undertook the defence of all but a few lines of B as well, dismantling much of my case against it and adding the argument that the transmitted ending mirrors the play's beginning and is therefore presumptively Sophoclean. The present article, in part a reply to Sommerstein's reply, restates some of my earlier arguments and also presents new evidence for the spuriousness of B.
Retirement migration, the ‘other’ story: caring for frail elderly British citizens in Spain
Authors: HALL KELLY , HARDILL IRENE
Published: December 2014

Recent years have seen a growth in research on retirement/lifestyle migration to Spain, however this has tended to focus on the reasons for moving, as well as the lifestyles adopted as part of a healthy and active retirement. However, ageing in Spain can bring challenges as a person's resources for independent living diminish. This paper draws on narrative interviews with vulnerable older British people in Spain, focusing on those who have encountered a severe decline in health, are frail and in need of care. It looks at the formal and informal networks and agencies that support these individuals, in particular the resources and strategies they employ to access care. Drawing on a framework of care provision developed by Glucksmann and Lyons, four broad modes of provision for old age care used by older British people in Spain are identified: state/public, family/community, voluntary/not-for-profit and market/for-profit. The paper argues that there are language, cultural, spatial and financial barriers when accessing care in Spain as an older British citizen. It is concluded that there are some frail, vulnerable people that may fall through a support gap, whereby they are no longer the responsibility of UK welfare services, yet not fully recognised in their new country of residence, and asks if more should be done to support this population.
The rigid S-type cable-suspended parallel robot design, modelling and analysis
Authors: Filipovic M. , Djuric A. , Kevac Lj.
Published: December 2014

This paper presents design, modelling and analysis of the selected Rigid ropes S-type Cable-suspended Parallel Robot (RSCPR). The characteristic of this system is its geometric construction which defines the kinematic model through the Jacobian matrix. The relationship between external and internal forces is defined by the Lagrange principle of virtual work. The Jacobian matrix is directly involved in the application of the Lagrange principle of virtual work and generation of the dynamic model of the RSCPR system. Selected examples of the CPR system types are analysed and the comparison of their results is presented. The software package named ORIGI has been developed for the RSCPR model verification.
Evaluating the ecological and behavioural factors influencing Snowy PloverCharadrius nivosusegg hatching and the potential benefits of predator exclosures
Authors: PEARSON SCOTT F. , KNAPP SHANNON M. , SUNDSTROM CYNDIE
Published: December 2014

An understanding of the ecological factors influencing nest success and the effectiveness of management activities focused on improving nest success can be critical to successful conservation strategies for rare or declining species. Over seven breeding seasons (2006–2012) we examined the influence of nest spacing and habitat characteristics on hatching success for the nationally threatened Pacific coast population of the Snowy PloverCharadrius nivosusin coastal Washington, USA in two study areas. Specifically, we assessed the influence of clutch age, nesting season date, distance to conspecific nests, perpendicular distance to the high-tide (wrack) line, vegetation cover and other habitat characteristics at three spatial scales (1m2, 5m2, and 25 m2) centred on the nest. We also assessed the effectiveness of wire mesh cages placed around nests to exclude mammalian and avian nest-predators. We discovered and monitored 307 nests, placed predator exclosures around 142 of these nests and measured habitat variables at 251. Our selected base model included site and quadratic function of season-date. For the analysis examining habitat effects on nest success, only models with distance to nearest active nest ranked higher than the baseline model even when removing the nests that were very distant from conspecific nests (outliers). For these unexclosed nests, predation was the primary source of nest failure and crows and ravens were apparently the primary nest predators. Predator exclosures had a clear positive influence on nest survival. Even though we observed a positive exclosure effect, we recommend that they be used cautiously because we and others have observed adult mortality associated with exclosures. Regardless of the spatial scale, Snowy Plovers are primarily using nest sites with little vegetation, shell or woody material cover suggesting the need for large expanses of very sparsely or unvegetated habitats that allow birds to nest semi-colonially (with near neighbours).
AN ANSWER TO THE QUESTION: WHAT IS DECOLONIZATION? FRANTZ FANON’STHE WRETCHED OF THE EARTHAND JEAN-PAUL SARTRE’SCRITIQUE OF DIALECTICAL REASON*
Authors: ETHERINGTON BEN
Published: December 2014

This essay argues that Jean-Paul Sartre's notion of “dialectical reason”, as elaborated in hisCritique of Dialectical Reason(1960), had a decisive impact on the composition of Frantz Fanon'sThe Wretched of the Earth(1961). The relationship between the two works has not before received a thorough textual exposition. Such an exposition, it is suggested, also entails revising the view of the nature of Fanon's work that has become entrenched in anglophone scholarship. Instead of a self-grounding theorist who more resembles the postcolonialists who would succeed him, this essay presents a view of Fanon as a situated theorist, drawing on those resources that could best help him to articulate the task at hand. The notion of “dialectical reason” allowed him to break from his previous understanding of decolonization as the attainment of reason through struggle, and see the “praxis” of revolution as, itself, self-realizing reason. To perceive this allows us better to seize on the thinking that guides his discussions of objectification under colonialism, anticolonial violence, and the role of the national bourgeoisie, and, thus, to clear up a number of controversies.
Legislative Power and Women's Representation
Authors: Schwindt-Bayer Leslie , Squire Peverill
Published: December 2014

Women's representation in national legislatures varies widely around the world. In 2012, only Rwanda and Andorra had achieved parity in women's representation in the national parliament, with 56% of the Rwandan Chamber of Deputies being female and exactly half the Andorran General Council represented by each sex. In many other countries, women still have little representation in the national legislature, despite being almost 50% of the population. A large body of research has emerged to try to explain the wide variation across countries, with most of it focusing on cultural, socioeconomic, and electoral explanations (e.g., McDonagh 2002; Norris 1985; Reynolds 1999; Rule 1987; Tripp and Kang 2008). Recent scholarship, however, has suggested that the legislature itself is a gendered institution that marginalizes women and argues for greater attention to understanding exactly how legislative institutions affect women's representation (Beckwith 2005; Chappell 2006; 2010; Duerst-Lahti and Kelly 1995; Hawkesworth 2003; 2005; Krook and Mackay 2011; Schwindt-Bayer 2010).
Viral suppressors of the RIG-I-mediated interferon response are pre-packaged in influenza virions
Authors: Liedmann Swantje , Hrincius Eike R. , Guy Cliff , Anhlan Darisuren , Dierkes Rüdiger , Carter Robert , Wu Gang , Staeheli Peter , Green Douglas R. , Wolff Thorsten , McCullers Jonathan A. , Ludwig Stephan , Ehrhardt Christina
Published: December 2014

The type I interferon (IFN) response represents the first line of defence to invading pathogens. Internalized viral ribonucleoproteins (vRNPs) of negative-strand RNA viruses induce an early IFN response by interacting with retinoic acid inducible gene I (RIG-I) and its recruitment to mitochondria. Here we employ three-dimensional stochastic optical reconstruction microscopy (STORM) to visualize incoming influenza A virus (IAV) vRNPs as helical-like structures associated with mitochondria. Unexpectedly, an early IFN induction in response to vRNPs is not detected. A distinct amino-acid motif in the viral polymerases, PB1/PA, suppresses early IFN induction. Mutation of this motif leads to reduced pathogenicity in vivo, whereas restoration increases it. Evolutionary dynamics in these sequences suggest that completion of the motif, combined with viral reassortment can contribute to pandemic risks. In summary, inhibition of the immediate anti-viral response is ‘pre-packaged’ in IAV in the sequences of vRNP-associated polymerase proteins.
OM14 is a mitochondrial receptor for cytosolic ribosomes that supports co-translational import into mitochondria
Authors: Lesnik Chen , Cohen Yifat , Atir-Lande Avigail , Schuldiner Maya , Arava Yoav
Published: December 2014

It is well established that import of proteins into mitochondria can occur after their complete synthesis by cytosolic ribosomes. Recently, an additional model was revived, proposing that some proteins are imported co-translationally. This model entails association of ribosomes with the mitochondrial outer membrane, shown to be mediated through the ribosome-associated chaperone nascent chain-associated complex (NAC). However, the mitochondrial receptor of this complex is unknown. Here, we identify the Saccharomyces cerevisiae outer membrane protein OM14 as a receptor for NAC. OM14Δ mitochondria have significantly lower amounts of associated NAC and ribosomes, and ribosomes from NAC[Δ] cells have reduced levels of associated OM14. Importantly, mitochondrial import assays reveal a significant decrease in import efficiency into OM14Δ mitochondria, and OM14-dependent import necessitates NAC. Our results identify OM14 as the first mitochondrial receptor for ribosome-associated NAC and reveal its importance for import. These results provide a strong support for an additional, co-translational mode of import into mitochondria.
Universal electronics for miniature and automated chemical assays
Authors: Urban Pawel L.
Published: December 2014

Generic electronic modules greatly simplify the development of new analytical instruments.
Differentiation of prostate cancer from normal tissue in radical prostatectomy specimens by desorption electrospray ionization and touch spray ionization mass spectrometry
Authors: Kerian K. S. , Jarmusch A. K. , Pirro V. , Koch M. O. , Masterson T. A. , Cheng L. , Cooks R. G.
Published: December 2014

Prostate cancer is distinguished reliably (>95% accuracy) from normal tissue using ambient spray ionization in a rapid diagnostic measurement.
Fabrication of ultra-thin polyrotaxane-based films via solid-state continuous assembly of polymers
Authors: Tan Shereen , Nam Eunhyung , Cui Jiwei , Xu Chenglong , Fu Qiang , Ren Jing M. , Wong Edgar H. H. , Ladewig Katharina , Caruso Frank , Blencowe Anton , Qiao Greg G.
Published: December 2014

Surface-confined ultra-thin polyrotaxane (PRX)-based films with tunable composition, surface topology and swelling characteristics were prepared by solid-state continuous assembly of polymers (ssCAP).
Spiroguanidine rhodamines as fluorogenic probes for lysophosphatidic acid
Authors: Wang Lei , Sibrian-Vazquez Martha , Escobedo Jorge O. , Wang Jialu , Moore Richard G. , Strongin Robert M.
Published: December 2014

Fluorescent indicators have been developed that enable the determination of lysophosphatidic acids via signaling that is independent of the size or degree of unsaturation of the fatty acid side chain.
Correction: Enhancing optical absorption of metal–organic frameworks for improved visible light photocatalysis
Authors: Nasalevich Maxim A. , Goesten Maarten G. , Savenije Tom J. , Kapteijn Freek , Gascon Jorge
Published: December 2014

Correction for ‘Enhancing optical absorption of metal–organic frameworks for improved visible light photocatalysis’ by Maxim A. Nasalevich et al., Chem. Commun., 2013, 49, 10575–10577.
Enantioselective 1,2-reductions of β-trifluoromethylated-α,β-unsaturated ketones to chiral allylic alcohols over organoruthenium-functionalized mesoporous silica nanospheres
Authors: Wu Meng , Kong Lingyu , Wang Kaiwen , Jin Ronghua , Cheng Tanyu , Liu Guohua
Published: December 2014

Organoruthenium-functionalized silica nanospheres display excellent catalytic activity and high enantioselectivity in the enantioselective 1,2-reductions of β-trifluoromethylated-α,β-unsaturated ketones.
Relationship between activation energy and pre-exponential factor normalized by the number of Brønsted acid sites in cracking of short chain alkanes on zeolites
Authors: Katada Naonobu , Sota Satoko , Morishita Nami , Okumura Kazu , Niwa Miki
Published: December 2014

Two different relationships between activation entropy and enthalpy in alkane cracking over various zeolites suggest a difference in the reaction mechanism.
Representativeness of shorter measurement sessions in long-term indoor air monitoring
Authors: Maciejewska M. , Szczurek A.
Published: December 2014

Indoor air quality (IAQ) considerably influences health, comfort and the overall performance of people who spend most of their lives in confined spaces.
Contaminant classification using cosine distances based on multiple conventional sensors
Authors: Liu Shuming , Che Han , Smith Kate , Chang Tian
Published: December 2014

This paper proposes a new contaminant classification method to discriminate contaminants in a real time manner, independent of the contaminant concentration. The proposed method quantifies the similarities or dissimilarities between sensors' responses to different types of contaminants. The performance of the proposed method was evaluated using data from injection experiments and compared with a Euclidean distance-based method.
Development and field testing of a miniaturized sampling system for simultaneous sampling of vapours and droplets
Authors: Breuer Dietmar , Dragan George C. , Friedrich Claudia , Möhlmann Carsten , Zimmermann Ralf
Published: December 2014

The sampling of semi volatiles (SV) in workplaces may lead to inaccurate results as measurements can be affected by sampling bias.
Atomic spectrometry in China: past and present
Authors: Wang Xiaohua , Zhang Shudi , Xu Zhouyi , Lin Junyue , Huang Benli , Hang Wei
Published: December 2014

This review focuses on the developments of atomic spectrometry (AS) in China since the founding of the People's Republic in 1949.
Synthesis of amine functionalized graphite nanosheets and their water-soluble derivative for drug loading and controlled release
Authors: Chakravarty Amrita , Bhowmik Koushik , De Goutam , Mukherjee Arnab
Published: December 2014

Amine functionalized graphite nanosheets are formed by facile chemical functionalization and their water soluble PEGylated derivative is prepared for drug loading and controlled release.
Dansyl-carbazole AIEE material for selective recognition of thiourea derivatives
Authors: Sharma Shilpa , Pradeep Chullikkattill. P. , Dhir Abhimanew
Published: December 2014

New dansyl-carbazole based compound 3 is designed and synthesized, which exhibits aggregation induced emission enhancement (AIEE) behaviour in H2O : THF (60 : 40, v/v). Aggregates of compound 3 in H2O : THF (60 : 40, v/v) selectively recognize thiourea motifs over urea motifs.
Unveiling the shape-diversified silicon nanowires made by HF/HNO3 isotropic etching with the assistance of silver
Authors: Chen Chia-Yun , Wong Ching-Ping
Published: December 2014

A new etching strategy for preparing shape-diversified silicon nanowires with smooth surfaces was reported.
Enabling the (3 + 2) cycloaddition reaction in assembling newer anti-tubercular lead acting through the inhibition of the gyrase ATPase domain: lead optimization and structure activity profiling
Authors: Jeankumar Variam Ullas , Reshma Rudraraju Srilakshmi , Janupally Renuka , Saxena Shalini , Sridevi Jonnalagadda Padma , Medapi Brahmam , Kulkarni Pushkar , Yogeeswari Perumal , Sriram Dharmarajan
Published: December 2014

Exploring the Gyrase ATPase platform to tailor novel anti-tubercular leads.
N-Phosphonyl/phosphinyl imines and group-assisted purification (GAP) chemistry/technology
Authors: An Guanghui , Seifert Cole , Li Guigen
Published: December 2014

Group-assisted purification (GAP) chemistry, which can provide various chiral amines and other functionalities without the use of column chromatography or recrystallization; products are consistently obtained with excellent stereocontrol.
Chemoselective efficient synthesis of functionalized β-oxonitriles through cyanomethylation of Weinreb amides
Authors: Mamuye Ashenafi Damtew , Castoldi Laura , Azzena Ugo , Holzer Wolfgang , Pace Vittorio
Published: December 2014

Homologation of Weinreb amides with cyanomethyllithium: a new route to β-oxonitriles.
Regulating the cytoprotective response in cancer cells using simultaneous inhibition of Hsp90 and Hsp70
Authors: Wang Y. , McAlpine S. R.
Published: December 2014

Both heat shock protein 90 and 70 (Hsp90, Hsp70) are cytoprotective proteins that regulate cell function and faciliate cell growth by stabilizing and folding proteins.
Realization of fluorescence color tuning for poly(p-phenylenevinylene) coated microspheres via a heterogeneous catalytic thermal elimination process
Authors: Chen Yun , Qiu Tian , Zhao Wei , Fan Li-Juan
Published: December 2014

Fluorescent microspheres with clear core–shell structures and various emission colors were successfully prepared via a catalytic elimination process.
Solution blown sulfonated poly(ether ether ketone) nanofiber–Nafion composite membranes for proton exchange membrane fuel cells
Authors: Xu Xianlin , Li Li , Wang Hang , Li Xiaojie , Zhuang Xupin
Published: December 2014

The incorporation of SPEEK nanofibers into a Nafion matrix enhanced the performance of the composite membrane as a proton exchange membrane.
From two-dimensional to one-dimensional structures: SiC nano-whiskers derived from graphene via a catalyst-free carbothermal reaction
Authors: Liu Zhuo , Kong Qing-Qiang , Chen Cheng-Meng , Zhang Qiang , Hu Ling , Li Xiao-Ming , Han Pei-De , Cai Rong
Published: December 2014

β-SiC nano-whiskers are synthesized by a facile catalyst-free carbothermal reaction between graphene and silicon powders.
Covalent crosslinked polyelectrolyte complex membrane with high negative charges towards anti-natural organic matter fouling nanofiltration
Authors: Shan Linglong , Guo Hongxia , Qin Zhenping , Wang Naixin , Ji Shulan , Zhang Guojun , Zhang Zhongguo
Published: December 2014

Removal of natural organic matter (NOM) from drinking water by membrane technology is attracting increasing attention.
Preparation of cucurbit[6]uril-modified polymer monolithic column for microextraction of nitroaromatics
Authors: Zheng Haijiao , Li Zheng , Zhang Jingchun , Ma Jiutong , Zhou Yufeng , Jia Qiong
Published: December 2014

Monolithic poly(glycidyl methacrylate-co-ethylene dimethacrylate) capillary column incorporated with cucurbit[6]uril pseudorotaxane (CB[6]MR) was prepared and used in polymer monolith microextraction for the preconcentration of nitroaromatics.
Harvesting electricity from benzene and ammonium-contaminated groundwater using a microbial fuel cell with an aerated cathode
Authors: Wei Manman , Harnisch Falk , Vogt Carsten , Ahlheim Jörg , Neu Thomas R. , Richnow Hans H.
Published: December 2014

A microbial fuel cell (MFC) was successfully applied for the treatment of benzene and ammonium co-contaminated groundwater.
Fluorescence enhancement of fisetin by silver nanoparticles with cetyltrimethyl ammonium bromide micelles
Authors: Liu Xiaodan , Wu Xia
Published: December 2014

The synergistic action of solubilization and sensitization of CTAB micelles and metal-enhanced fluorescence of AgNPs enhance fluorescence intensity of fisetin.
Anti-bacterial performances and biocompatibility of bacterial cellulose/graphene oxide composites
Authors: Shao Wei , Liu Hui , Liu Xiufeng , Wang Shuxia , Zhang Rui
Published: December 2014

Bacterial cellulose/graphene oxide composites have excellent anti-bacterial activities and good compatibility.
An unique solvent assisted ‘green’ hydrotropic precipitation and response surface optimization for isolation of the dietary micronutrient β-sitosterol-d-glucopyranoside from Desmostachya bipinnata
Authors: Subramaniam Shankar , Palanisamy Anbumathi , Sivasubramanian Aravind
Published: December 2014

Novel Box–Behnken optimized isolation of the dietary micronutrient β-sitosterol-d-glucopyranoside by solvent assisted ‘green’ hydrotropic precipitation from Desmostachya bipinnata.
Screening of antidote sensitivity using an acetylcholinesterase biosensor based on a graphene–Au nanocomposite
Authors: Long Linjuan , Luo Yanan , Liu Bingwen , Du Dan , Lin Yuehe
Published: December 2014

An AChE biosensor based on graphene–Au nanocomposite was constructed for screening of the therapeutic effects of three oximes antidotes.
Kinetic resolution of secondary alcohols with Burkholderia cepacia lipase immobilized on a biodegradable ternary blend polymer matrix as a highly efficient and heterogeneous recyclable biocatalyst
Authors: More Ganesh V. , Badgujar Kirtikumar C. , Bhanage Bhalchandra M.
Published: December 2014

A greener and superficial protocol for the synthesis of enantiomerically pure alcohols and their enantioriched acetate derivatives using a biodegradable heterogeneous recyclable catalyst with high conversion has been developed.
One pot green synthesis of graphene–iron oxide nanocomposite (GINC): an efficient material for enhancement of thermoelectric performance
Authors: Dey Abhijit , Panja Sudipta , Sikder Arun Kanti , Chattopadhyay Santanu
Published: December 2014

We report for the first time, a green method for graphene–iron oxide nanocomposite (GINC) synthesis by dispersing graphene and nano iron oxide (Fe2O3) in ethanolviaultrasonication followed by micro-wave irradiation.
Light-driven reversible strand displacement using glycerol azobenzene inserted DNA
Authors: Kou Bo , Zhang Jiaxiao , Huai Xu , Liang Xingguo , Xiao Shou-Jun
Published: December 2014

Tethered with bistable 2′,6′-dimethylazobenzene via a glycerol linker, an artificial 35 nt-long DNA has performed photoresponsive hybridization and reversible light-driven strand displacement.
Structure and ionic conductivity of liquid crystals having propylene carbonate units
Authors: Eisele Andreas , Kyriakos Konstantinos , Bhandary Rajesh , Schönhoff Monika , Papadakis Christine M. , Rieger Bernhard
Published: December 2014

Synthesis and investigation of liquid crystalline molecules with cyclic carbonate units, which exhibit spontaneous alignment and enhanced ionic conductivity.
Core–shell Fe3O4@SiO2@HNbMoO6 nanocomposites: new magnetically recyclable solid acid for heterogeneous catalysis
Authors: Shen P. , Zhang H. T. , Liu H. , Xin J. Y. , Fei L. F. , Luo X. G. , Ma R. Z. , Zhang S. J.
Published: December 2014

A modified layer-by-layer self-assembly process was developed to fabricate magnetically recyclable solid acid catalyst for acetalization and acetalization reactions.
Preparation of titania based biocatalytic nanoparticles and membranes for CO2conversion
Authors: Hou Jingwei , Dong Guangxi , Xiao Bowen , Malassigne Charly , Chen Vicki
Published: December 2014

Novel TiO2based biocatalytic nanoparticles and membranes were prepared, which could be used for CO2conversion in gas–liquid membrane contactors.
Enhancing the performance of dye-sensitized solar cells: doping SnO2photoanodes with Al to simultaneously improve conduction band and electron lifetime
Authors: Duan Yandong , Zheng Jiaxin , Fu Nianqing , Fang Yanyan , Liu Tongchao , Zhang Qian , Zhou Xiaowen , Lin Yuan , Pan Feng
Published: December 2014

Al-doping of SnO2photoanodes can simultaneously improve conduction band and electron lifetime of high-performance dye-sensitized solar cells.
A versatile strategy to directly synthesize 4,8-functionalized benzo[1,2-b:4,5-b′]difurans for organic electronics
Authors: Bian Linyi , Hai Jiefeng , Zhu Enwei , Yu Jiangsheng , Liu Yun , Zhou Jie , Ge Guidong , Tang Weihua
Published: December 2014

A direct synthesis of 4,8-functionalized benzo[1,2-b:4,5-b′]difurans was developed for organic electronics, with a power conversion efficiency 4.61% for polymer solar cells.
Supercapacitive energy storage performance of molybdenum disulfide nanosheets wrapped with microporous carbons
Authors: Weng Qunhong , Wang Xi , Wang Xuebin , Zhang Chao , Jiang Xiangfen , Bando Yoshio , Golberg Dmitri
Published: December 2014

A structure composed of a pseudocapacitive core (MoS2nanosheets) and an electrostatic double-layer capacitive porous shell (MOF-derived microporous carbons) was developed for advanced electrochemical energy storage.
Triisopropylsilylethynyl substituted benzodithiophene copolymers: synthesis, properties and photovoltaic characterization
Authors: Zhu Enwei , Luo Guoping , Liu Yun , Yu Jiangsheng , Zhang Fujun , Che Guangbo , Wu Hongbin , Tang Weihua
Published: December 2014

We demonstrated herein the facile synthesis of triisopropylsilylethynyl (TIPS) functionalized benzo[1,2-b:4,5-b′]dithiophene (BDT) for efficient polymer solar cells.
Intramolecular charge transfer (ICT) of a chiroptically active conjugated polymer showing green colour
Authors: Kawashima Hirotsugu , Kawabata Kohsuke , Goto Hiromasa
Published: December 2014

An optically active, green-coloured π-conjugated polymer film was prepared by electrochemical synthesis in a chiral liquid crystalline medium, and charge carriers are generated in the chiral conjugated system.
Role of NADPH oxidase in the regulation of autophagy in cardiomyocytes
Authors: Sciarretta Sebastiano , Yee Derek , Ammann Paul , Nagarajan Narayani , Volpe Massimo , Frati Giacomo , Sadoshima Junichi
Published: December 2014

In the past several years, it has been demonstrated that the reactive oxygen species (ROS) may act as intracellular signalling molecules to activate or inhibit specific signalling pathways and regulate physiological cellular functions. It is now well-established that ROS regulate autophagy, an intracellular degradation process. However, the signalling mechanisms through which ROS modulate autophagy in a regulated manner have only been minimally clarified. NADPH oxidase (Nox) enzymes are membrane-bound enzymatic complexes responsible for the dedicated generation of ROS. Different isoforms of Nox exist with different functions. Recent studies demonstrated that Nox-derived ROS can promote autophagy, with Nox2 and Nox4 representing the isoforms of Nox implicated thus far. Nox2- and Nox4-dependent autophagy plays an important role in the elimination of pathogens by phagocytes and in the regulation of vascular- and cancer-cell survival. Interestingly, we recently found that Nox is also important for autophagy regulation in cardiomyocytes. We found that Nox4, but not Nox2, promotes the activation of autophagy and survival in cardiomyocytes in response to nutrient deprivation and ischaemia through activation of the PERK (protein kinase RNA-like endoplasmic reticulum kinase) signalling pathway. In the present paper, we discuss the importance of Nox family proteins and ROS in the regulation of autophagy, with a particular focus on the role of Nox4 in the regulation of autophagy in the heart.
Stability of an improved dynamic quantised system with time‐varying delay and packet losses
Authors: Li Mu , Sun Jian , Dou Lihua
Published: December 2014

The stability problem of a linear dynamic quantised system with time‐varying delay and packet losses is studied in this article. An optimal dynamic quantiser which is able to minimise the maximum output error between the quantised system and unquantised systems is designed, and the minimum upper bound of the quantised error is also given. Moreover, the system is lifted into a switched system for stability analysis and a sufficient condition for asymptotic stability is developed in terms of matrix inequalities. Finally, an illustrative example demonstrates the effectiveness of the proposed method.
Global output feedback stabilisation for a class of stochastic feedforward non‐linear systems with state time delay
Authors: Liu Liang , Yu Zhandong , Yu Jinyong , Zhou Qi
Published: December 2014

Global output feedback stabilisation problem for a class of stochastic feedforward non‐linear systems with state time delay is investigated in this study for the first time. By introducing the homogeneous domination approach in the stochastic system, constructing an implementable homogeneous reduced‐order observer and choosing an appropriate Lyapunov–Krasoviskii functional, an output feedback controller is designed to render the closed‐loop system globally asymptotically stable in probability and the output can be regulated to the origin almost surely. A simulation example is provided to show the effectiveness of the designed controller.
Excluded volume and ion-ion correlation effects on the ionic atmosphere around B-DNA: Theory, simulations, and experiments
Authors: Ovanesyan Zaven , Medasani Bharat , Fenley Marcia O. , Guerrero-García Guillermo Iván , Olvera de la Cruz Mónica , Marucho Marcelo
Published: December 2014

The ionic atmosphere around a nucleic acid regulates its stability in aqueous salt solutions. One major source of complexity in biological activities involving nucleic acids arises from the strong influence of the surrounding ions and water molecules on their structural and thermodynamic properties. Here, we implement a classical density functional theory for cylindrical polyelectrolytes embedded in aqueous electrolytes containing explicit (neutral hard sphere) water molecules at experimental solvent concentrations. Our approach allows us to include ion correlations as well as solvent and ion excluded volume effects for studying the structural and thermodynamic properties of highly charged cylindrical polyelectrolytes. Several models of size and charge asymmetric mixtures of aqueous electrolytes at physiological concentrations are studied. Our results are in good agreement with Monte Carlo simulations. Our numerical calculations display significant differences in the ion density profiles for the different aqueous electrolyte models studied. However, similar results regarding the excess number of ions adsorbed to the B-DNA molecule are predicted by our theoretical approach for different aqueous electrolyte models. These findings suggest that ion counting experimental data should not be used alone to validate the performance of aqueous DNA-electrolyte models.
Mg-MOF-74@SBA-15 hybrids: Synthesis, characterization, and adsorption properties
Authors: Chakraborty Anindita , Maji Tapas Kumar
Published: December 2014

Nanocrystals of Mg-MOF-74 have been immobilized into the mesopores of SBA-15 rods to fabricate Mg-MOF-74@SBA-15 hybrid materials. To furnish such composites, a relatively simple synthetic strategy has been adopted by direct dispersion of the metal-organic framework (MOF) precursors in SBA-15 matrix to prepare the hybrid materials in situ. The hybrid materials have been characterized using powder X-ray diffraction and several spectroscopic and microscopic techniques, which suggest growth of the MOF nanocrystals inside the SBA-15 mesopores and the composites exhibit characteristics of both the components. N2 adsorption isotherms at 77 K reveal that the composites contain additional mesopores, compared to only micropores of pristine MOF nanocrystals. In addition to such combination of both micro and mesoporosity, the composites also demonstrate significant CO2 adsorption at room temperature.
High-order harmonic generation using a high-repetition-rate turnkey laser
Authors: Lorek E. , Larsen E. W. , Heyl C. M. , Carlström S. , Paleček D. , Zigmantas D. , Mauritsson J.
Published: December 2014

We generate high-order harmonics at high pulse repetition rates using a turnkey laser. High-order harmonics at 400 kHz are observed when argon is used as target gas. In neon, we achieve generation of photons with energies exceeding 90 eV (∼13 nm) at 20 kHz. We measure a photon flux of up to 4.4 × 1010 photons per second per harmonic in argon at 100 kHz. Many experiments employing high-order harmonics would benefit from higher repetition rates, and the user-friendly operation opens up for applications of coherent extreme ultra-violet pulses in new research areas.
On the convective-absolute nature of river bedform instabilities
Authors: Vesipa Riccardo , Camporeale Carlo , Ridolfi Luca , Chomaz Jean Marc
Published: December 2014

River dunes and antidunes are induced by the morphological instability of stream-sediment boundary. Such bedforms raise a number of subtle theoretical questions and are crucial for many engineering and environmental problems. Despite their importance, the absolute/convective nature of the instability has never been addressed. The present work fills this gap as we demonstrate, by the cusp map method, that dune instability is convective for all values of the physical control parameters, while the antidune instability exhibits both behaviors. These theoretical predictions explain some previous experimental and numerical observations and are important to correctly plan flume experiments, numerical simulations, paleo-hydraulic reconstructions, and river works.
Poisson-Nernst-Planck-Fermi theory for modeling biological ion channels
Authors: Liu Jinn-Liang , Eisenberg Bob
Published: December 2014

A Poisson-Nernst-Planck-Fermi (PNPF) theory is developed for studying ionic transport through biological ion channels. Our goal is to deal with the finite size of particle using a Fermi like distribution without calculating the forces between the particles, because they are both expensive and tricky to compute. We include the steric effect of ions and water molecules with nonuniform sizes and interstitial voids, the correlation effect of crowded ions with different valences, and the screening effect of water molecules in an inhomogeneous aqueous electrolyte. Including the finite volume of water and the voids between particles is an important new part of the theory presented here. Fermi like distributions of all particle species are derived from the volume exclusion of classical particles. Volume exclusion and the resulting saturation phenomena are especially important to describe the binding and permeation mechanisms of ions in a narrow channel pore. The Gibbs free energy of the Fermi distribution reduces to that of a Boltzmann distribution when these effects are not considered. The classical Gibbs entropy is extended to a new entropy form — called Gibbs-Fermi entropy — that describes mixing configurations of all finite size particles and voids in a thermodynamic system where microstates do not have equal probabilities. The PNPF model describes the dynamic flow of ions, water molecules, as well as voids with electric fields and protein charges. The model also provides a quantitative mean-field description of the charge/space competition mechanism of particles within the highly charged and crowded channel pore. The PNPF results are in good accord with experimental currents recorded in a 108-fold range of Ca2+ concentrations. The results illustrate the anomalous mole fraction effect, a signature of L-type calcium channels. Moreover, numerical results concerning water density, dielectric permittivity, void volume, and steric energy provide useful details to study a variety of physical mechanisms ranging from binding, to permeation, blocking, flexibility, and charge/space competition of the channel.
On readout of vibrational qubits using quantum beats
Authors: Shyshlov Dmytro , Berrios Eduardo , Gruebele Martin , Babikov Dmitri
Published: December 2014

Readout of the final states of qubits is a crucial step towards implementing quantum computation in experiment. Although not scalable to large numbers of qubits per molecule, computational studies show that molecular vibrations could provide a significant (factor 2–5 in the literature) increase in the number of qubits compared to two-level systems. In this theoretical work, we explore the process of readout from vibrational qubits in thiophosgene molecule, SCCl2, using quantum beat oscillations. The quantum beats are measured by first exciting the superposition of the qubit-encoding vibrational states to the electronically excited readout state with variable time-delay pulses. The resulting oscillation of population of the readout state is then detected as a function of time delay. In principle, fitting the quantum beat signal by an analytical expression should allow extracting the values of probability amplitudes and the relative phases of the vibrational qubit states. However, we found that if this procedure is implemented using the standard analytic expression for quantum beats, a non-negligible phase error is obtained. We discuss the origin and properties of this phase error, and propose a new analytical expression to correct the phase error. The corrected expression fits the quantum beat signal very accurately, which may permit reading out the final state of vibrational qubits in experiments by combining the analytic fitting expression with numerical modelling of the readout process. The new expression is also useful as a simple model for fitting any quantum beat experiments where more accurate phase information is desired.
Role of the potential landscape on the single-file diffusion through channels
Authors: Goldt S. D. , Terentjev E. M.
Published: December 2014

Transport of colloid particles through narrow channels is ubiquitous in cell biology as well as becoming increasingly important for microfluidic applications or targeted drug delivery. Membrane channels in cells are useful models for artificial designs because of their high efficiency, selectivity, and robustness to external fluctuations. Here, we model the passive channels that let cargo simply diffuse through them, affected by a potential profile along the way. Passive transporters achieve high levels of efficiency and specificity from binding interactions with the cargo inside the channel. This however leads to a paradox: why should channels which are so narrow that they are blocked by their cargo evolve to have binding regions for their cargo if that will effectively block them? Using Brownian dynamics simulations, we show that different potentials, notably symmetric, increase the flux through narrow passive channels – and investigate how shape and depth of potentials influence the flux. We find that there exist optimal depths for certain potential shapes and that it is most efficient to apply a small force over an extended region of the channel. On the other hand, having several spatially discrete binding pockets will not alter the flux significantly. We also explore the role of many-particle effects arising from pairwise particle interactions with their neighbours and demonstrate that the relative changes in flux can be accounted for by the kinetics of the absorption reaction at the end of the channel.
Drag and torque coefficients for plate and disk induced stokes flows with slip
Authors: Davis Anthony M. J.
Published: December 2014

A key purpose of this paper is to demonstrate that the introduction of slip changes the structure of viscous flow past plates and disks by precluding edge singularities in the stresses. It is well-known that the inviscid limit flow is not recovered by letting the viscosity tend to zero. Here it is demonstrated that, similarly, the no-slip limit flow is not recovered by letting the slip coefficient tend to zero. For each of the three cases involving a translating plate and a rotating or translating disk, the determination of the tangential stress is reduced to a linear system of equations with simple coefficients. Values of the drag or torque and edge stresses are displayed.
Many-body exchange-overlap interactions in rare gases and water
Authors: Gillan M. J.
Published: December 2014

Generalized-gradient approximations (GGAs) of density-functional theory can suffer from substantial many-body errors in molecular systems interacting through weak non-covalent forces. Here, the errors of a range of GGAs for the 3-body energies of trimers of rare gases and water are investigated. The patterns of 3-body errors are similar for all the systems, and are related to the form of the exchange-enhancement factor FX(x) at large reduced gradient x, which also governs 2-body exchange-overlap errors. However, it is shown that the 3-body and 2-body errors depend in opposite ways on FX(x), so that they tend to cancel in molecular aggregates. Embedding arguments are used to achieve a partial separation of contributions to 3-body error from polarization, non-local correlation, and exchange, and it emerges that exchange is a major contributor. The practical importance of beyond-2-body errors is illustrated by the energetics of the water hexamer. An analysis of exchange-energy distributions is used to elucidate why 2-body and 3-body errors of GGAs depend in opposite ways on FX(x). The relevance of the present analysis to a range of other molecular systems is noted.
Derivative discontinuity and exchange-correlation potential of meta-GGAs in density-functional theory
Authors: Eich F. G. , Hellgren Maria
Published: December 2014

We investigate fundamental properties of meta-generalized-gradient approximations (meta-GGAs) to the exchange-correlation energy functional, which have an implicit density dependence via the Kohn-Sham kinetic-energy density. To this purpose, we construct the most simple meta-GGA by expressing the local exchange-correlation energy per particle as a function of a fictitious density, which is obtained by inverting the Thomas-Fermi kinetic-energy functional. This simple functional considerably improves the total energy of atoms as compared to the standard local density approximation. The corresponding exchange-correlation potentials are then determined exactly through a solution of the optimized effective potential equation. These potentials support an additional bound state and exhibit a derivative discontinuity at integer particle numbers. We further demonstrate that through the kinetic-energy density any meta-GGA incorporates a derivative discontinuity. However, we also find that for commonly used meta-GGAs the discontinuity is largely underestimated and in some cases even negative.
High light extraction efficiency in bulk-GaN based volumetric violet light-emitting diodes
Authors: David Aurelien , Hurni Christophe A. , Aldaz Rafael I. , Cich Michael J. , Ellis Bryan , Huang Kevin , Steranka Frank M. , Krames Michael R.
Published: December 2014

We report on the light extraction efficiency of III-Nitride violet light-emitting diodes with a volumetric flip-chip architecture. We introduce an accurate optical model to account for light extraction. We fabricate a series of devices with varying optical configurations and fit their measured performance with our model. We show the importance of second-order optical effects like photon recycling and residual surface roughness to account for data. We conclude that our devices reach an extraction efficiency of 89%.
A first-principles polarized Raman method for determining whether a uniform region of a sample is crystalline or isotropic
Authors: Weisman Andrew L. , DuBay Kateri H. , Willets Katherine A. , Friesner Richard A.
Published: December 2014

Previous methods for determining whether a uniform region of a sample is crystalline or isotropic—what we call the “state of internal orientation” \documentclass[12pt]{minimal}\begin{document}$\mathscr {S}$\end{document}S—require a prioriknowledge of properties of the purely crystalline and purely isotropic states. In addition, these methods can be ambiguous in their determination of state \documentclass[12pt]{minimal}\begin{document}$\mathscr {S}$\end{document}S for particular materials and, for a given material, the spectral methods can be ambiguous when using particular peaks. Using first-principles Raman theory, we have discovered a simple, non-resonance, polarized Raman method for determining the state \documentclass[12pt]{minimal}\begin{document}$\mathscr {S}$\end{document}S that requires no information a priori and will work unambiguously for any material using any vibrational mode. Similar to the concept behind “magic angle spinning” in NMR, we have found that for a special set of incident/analyzed polarizations and scattering angle, the dependence of the Raman modulation depth M on the sample composition—and, for crystalline regions, the unit cell orientation—falls out completely, leaving dependence on only whether the region is crystalline (M = 1) or isotropic (M = 0). Further, upon scanning between homogeneous regions or domains within a heterogeneous sample, our signal M is a clear detector of the region boundaries, so that when combined with methods for determining the orientations of the crystalline domains, our method can be used to completely characterize the molecular structure of an entire heterogeneous sample to a very high certainty. Interestingly, our method can also be used to determine when a given mode is vibrationally degenerate. While simulations on realistic terthiophene systems are included to illustrate our findings, our method should apply to any type of material, including thin films, molecular crystals, and semiconductors. Finally, our discovery of these relationships required derivations of Raman intensity formulas that are at least as general as any we have found, and herein we present our comprehensive formulas for both the crystalline and isotropic states.
Bottom-up derivation of conservative and dissipative interactions for coarse-grained molecular liquids with the conditional reversible work method
Authors: Deichmann Gregor , Marcon Valentina , van der Vegt Nico F. A.
Published: December 2014

Molecular simulations of soft matter systems have been performed in recent years using a variety of systematically coarse-grained models. With these models, structural or thermodynamic properties can be quite accurately represented while the prediction of dynamic properties remains difficult, especially for multi-component systems. In this work, we use constraint molecular dynamics simulations for calculating dissipative pair forces which are used together with conditional reversible work (CRW) conservative forces in dissipative particle dynamics (DPD) simulations. The combined CRW-DPD approach aims to extend the representability of CRW models to dynamic properties and uses a bottom-up approach. Dissipative pair forces are derived from fluctuations of the direct atomistic forces between mapped groups. The conservative CRW potential is obtained from a similar series of constraint dynamics simulations and represents the reversible work performed to couple the direct atomistic interactions between the mapped atom groups. Neopentane, tetrachloromethane, cyclohexane, and n-hexane have been considered as model systems. These molecular liquids are simulated with atomistic molecular dynamics, coarse-grained molecular dynamics, and DPD. We find that the CRW-DPD models reproduce the liquid structure and diffusive dynamics of the liquid systems in reasonable agreement with the atomistic models when using single-site mapping schemes with beads containing five or six heavy atoms. For a two-site representation of n-hexane (3 carbons per bead), time scale separation can no longer be assumed and the DPD approach consequently fails to reproduce the atomistic dynamics.