bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibacterial non-woven nanofibers of curcumin acrylate oligomers
Authors: Killi Naresh , Paul Vejendla Luke , Gundloori Rathna Venkata Naga
Published: March 2015

Oligomers of curcumin acrylates were blended with polylactide and electrospun to nanofiber mats, which were antibacterial and highly porous.
Cell penetrating peptide-based polyplexes shelled with polysaccharide to improve stability and gene transfection
Authors: Li Wenyu , Liu Yajie , Du Jianwei , Ren Kefeng , Wang Youxiang
Published: March 2015

A novel CPP-based polyplex shelled with polysaccharide was developed via host–guest interactions, which showed enhanced stability and gene transfection efficiency.
A predictive approach to CVD of crystalline layers of TMDs: the case of MoS2
Authors: Kranthi Kumar V. , Dhar Sukanya , Choudhury Tanushree H. , Shivashankar S. A. , Raghavan Srinivasan
Published: March 2015

A generic approach suitable to all TMDs has been demonstrated. Thermodynamic modeling identifies the appropriate CVD process window and the growth is controlled by tuning the vapor phase supersaturation. Consequently MoS2 growth, bulk to monolayers, has been achieved.
Methane capture at room temperature: adsorption on cubic δ-MoC and orthorhombic β-Mo2C molybdenum carbide (001) surfaces
Authors: Posada-Pérez Sergio , dos Santos Politi José Roberto , Viñes Francesc , Illas Francesc
Published: March 2015

By means of an surrealistic picture, one can see the most prominent result in this paper; the capacity of δ-MoC(001) surface to sequester methane molecule at room temperature.
Ultrasensitive colorimetric assay of cadmium ion based on silver nanoparticles functionalized with 5-sulfosalicylic acid for wide practical applications
Authors: Jin Weiwei , Huang Pengcheng , Wu Fangying , Ma Li-Hua
Published: March 2015

A simple, low-cost yet very sensitive and selective colorimetric assay for Cd2+ is introduced based on 5-sulfosalicylic acid functionalized silver nanoparticles.
Ag@SiO2-entrapped hydrogel microarray: a new platform for a metal-enhanced fluorescence-based protein assay
Authors: Jang Eunji , Kim Minsu , Koh Won-Gun
Published: March 2015

We developed a novel silver-based metal-enhanced fluorescence (MEF) biosensing platform that consisted of poly(ethylene glycol)(PEG) hydrogel microstructures entrapping silica-coated silver nanoparticles (Ag@SiO2).
Metabolic profiling analysis of root exudates from the Cd hyperaccumulator Sedum alfredii under different Cd exposure concentrations and times
Authors: Luo Qing , Sun Li-na , Wang Hui , Hu Xiao-min
Published: March 2015

The variation of root exudates from the Cd hyperaccumulator Sedum alfredii under different Cd exposure concentrations and times was researched.
Fluorescence-detected magnetic field effects on radical pair reactions from femtolitre volumes
Authors: Dodson C. A. , Wedge C. J. , Murakami M. , Maeda K. , Wallace M. I. , Hore P. J.
Published: March 2015

Using total internal reflection fluorescence microscopy the effects of applied magnetic fields on radical pair reactions can be sensitively measured from sample volumes as low as ∼100 fL.
Revisiting the assembly of amino ester-based benzene-1,3,5-tricarboxamides: chiral rods in solution
Authors: Desmarchelier Alaric , Raynal Matthieu , Brocorens Patrick , Vanthuyne Nicolas , Bouteiller Laurent
Published: March 2015

Long rods and strong chiral amplification can be obtained from amino ester-based BTAs, by a suitable choice of structure and concentration.
Lorentz microscopy sheds light on the role of dipolar interactions in magnetic hyperthermia
Authors: Campanini M. , Ciprian R. , Bedogni E. , Mega A. , Chiesi V. , Casoli F. , de Julián Fernández C. , Rotunno E. , Rossi F. , Secchi A. , Bigi F. , Salviati G. , Magén C. , Grillo V. , Albertini F.
Published: March 2015

Left: morphological and magnetic characterization of magnetite NPs. Right: Lorentz microscopy unveils the role of dipolar interactions in magnetic hyperthermia of superparamagnetic NPs.
Impact of anatase and rutile titanium dioxide nanoparticles on uptake carriers and efflux pumps in Caco-2 gut epithelial cells
Authors: Dorier M. , Brun E. , Veronesi G. , Barreau F. , Pernet-Gallay K. , Desvergne C. , Rabilloud T. , Carapito C. , Herlin-Boime N. , Carrière M.
Published: March 2015

TiO2-NPs, both anatase and rutile, accumulate in Caco-2 cells and up-regulate a battery of nutrient transporters and efflux pumps, but do not cause overt mortality or DNA damage.
Nitroxides as anti-biofilm compounds for the treatment of Pseudomonas aeruginosa and mixed-culture biofilms
Authors: Alexander Stefanie-Ann , Kyi Caroline , Schiesser Carl H.
Published: March 2015

A series of nitroxides was prepared and tested for bacterial biofilm modulatory activity.
C5-azobenzene-functionalized locked nucleic acid uridine: isomerization properties, hybridization ability, and enzymatic stability
Authors: Morihiro K. , Hasegawa O. , Mori S. , Tsunoda S. , Obika S.
Published: March 2015

C5-azobenzene-functionalized locked nucleic acid uridine (LNA-UAz) shows effective photo-isomerization properties, RNA-selective hybridization ability, and high enzymatic stability.
The effects of divalent copper on performance, extracellular polymeric substances and microbial community of an anoxic–aerobic sequencing batch reactor
Authors: Wang Sen , Gao Mengchun , Wang Zhichao , She Zonglian , Jin Chunji , Zhao Yangguo , Li Zhiwei
Published: March 2015

The effects of divalent copper (Cu(ii)) on the performance, extracellular polymeric substances (EPS) and microbial community of activated sludge were investigated in an anoxic–aerobic sequencing batch reactor (SBR).
One pot oxidative cleavage of cyclohexene to adipic acid using silver tungstate nano-rods in a Brønsted acidic ionic liquid
Authors: Vafaeezadeh Majid , Mahmoodi Hashemi Mohammad
Published: March 2015

The first catalytic application of silver tungstate is disclosed for the synthesis of adipic acid from the oxidative cleavage of cyclohexene.
Facile synthesis of flower-like CoMn2O4 microspheres for electrochemical supercapacitors
Authors: Ren Long , Chen Jun , Wang Xiaoqing , Zhi Mingjia , Wu Junwei , Zhang Xinhe
Published: March 2015

Facile synthesis of porous and hollow spinel materials is highly desirable for their extensive applications in energy storage fields.
A new ICT and CHEF based visible light excitable fluorescent probe easily detects in vivo Zn2+
Authors: Aich Krishnendu , Goswami Shyamaprosad , Das Sangita , Mukhopadhyay Chitrangada Das
Published: March 2015

A new chelator and ICT donor based visible light excitable Zn2+sensor was designed and developed by integrating quinoline and 2-hydroxy-3-(hydroxymethyl)-5-methylbenzaldehyde.
Preparation and properties of stretchable and tough alginate/polyacrylamide hollow capsules
Authors: Zhu Ming-Lu , Li Yan-Li , Zhang Zi-Mou , Jiang Yong
Published: March 2015

Stretchable and tough hollow capsules were synthesized using alginate and polyacrylamide and their volume could be expanded at least 27 times their original size.
Energy and dose dependence of proton-irradiation damage in graphene
Authors: Yang Gwangseok , Kim Byung-Jae , Kim Kyeounghak , Han Jeong Woo , Kim Jihyun
Published: March 2015

The dependence of radiation-induced damage in monolayer graphene on both the proton energy and dose was systematically investigated.
Ultralow dielectric, high performing hyperbranched epoxy thermosets: synthesis, characterization and property evaluation
Authors: De Bibekananda , Karak Niranjan
Published: March 2015

The present work addresses the major drawbacks, such as low toughness character and high dielectric constant, of conventional epoxy thermosets through macromolecular engineering.
Self-induced redox cycling coupled luminescence on nanopore recessed disk-multiscale bipolar electrodes
Authors: Ma Chaoxiong , Zaino III Lawrence P. , Bohn Paul W.
Published: March 2015

Self-induced redox cycling at nanopore ring-disk electrodes is coupled, through a bipolar electrode, to a remote fluorigenic reporter reaction.
A device for rapid and quantitative measurement of cardiac myocyte contractility
Authors: Gaitas Angelo , Malhotra Ricky , Li Tao , Herron Todd , Jalife José
Published: March 2015

Cardiac contractility is the hallmark of cardiac function and is a predictor of healthy or diseased cardiac muscle. Despite advancements over the last two decades, the techniques and tools available to cardiovascular scientists are limited in their utility to accurately and reliably measure the amplitude and frequency of cardiomyocyte contractions. Isometric force measurements in the past have entailed cumbersome attachment of isolated and permeabilized cardiomyocytes to a force transducer followed by measurements of sarcomere lengths under conditions of submaximal and maximal Ca2+ activation. These techniques have the inherent disadvantages of being labor intensive and costly. We have engineered a micro-machined cantilever sensor with an embedded deflection-sensing element that, in preliminary experiments, has demonstrated to reliably measure cardiac cell contractions in real-time. Here, we describe this new bioengineering tool with applicability in the cardiovascular research field to effectively and reliably measure cardiac cell contractility in a quantitative manner. We measured contractility in both primary neonatal rat heart cardiomyocyte monolayers that demonstrated a beat frequency of 3 Hz as well as human embryonic stem cell-derived cardiomyocytes with a contractile frequency of about 1 Hz. We also employed the β-adrenergic agonist isoproterenol (100 nmol l−1) and observed that our cantilever demonstrated high sensitivity in detecting subtle changes in both chronotropic and inotropic responses of monolayers. This report describes the utility of our micro-device in both basic cardiovascular research as well as in small molecule drug discovery to monitor cardiac cell contractions.
Photoelectron imaging and photodissociation of ozonide in O3− ⋅ (O2)n (n = 1-4) clusters
Authors: Mann Jennifer E. , Troyer Mary E. , Jarrold Caroline Chick
Published: March 2015

The photoelectron images of O3− and O3− ⋅ (O2)n (n = 1–4) have been measured using 3.49 eV photon energy. The spectra exhibit several processes, including direct photodetachment and photodissociation with photodetachment of O− photofragments. Several spectra also exhibit autodetachment of vibrationally excited O2− photofragments. Comparison of the bare O3− photoelectron spectra to that of the complexes shows that the O3− core is preserved upon clustering with several O2 molecules, though subtle changes in the Franck-Condon profile of the ground state photodetachment transition suggest some charge transfer from O3− to the O2 molecules. The electron affinities of the complexes increase by less than 0.1 eV with each additional O2 molecule, which is comparable to the corresponding binding energy [K. Hiraoka, Chem. Phys. 125, 439-444 (1988)]. The relative intensity of the photofragment O− detachment signal to the O3− ⋅ (O2)n direct detachment signal increases with cluster size. O2− autodetachment signal is only observed in the O3−, O3− ⋅ (O2)3, and O3− ⋅ (O2)4 spectra, suggesting that the energy of the dissociative state also varies with the number of O2 molecules present in the cluster.
Solution of the inverse Langevin problem for open dissipative systems with anisotropic interparticle interaction
Authors: Lisin E. A. , Lisina I. I. , Vaulina O. S. , Petrov O. F.
Published: March 2015

Solution of the inverse Langevin problem is presented for open dissipative systems with anisotropic interparticle interaction. Possibility of applying this solution for experimental determining the anisotropic interaction forces between dust particles in complex plasmas with ion flow is considered. For this purpose, we have tested the method on the results of numerical simulation of chain structures of particles with quasidipole-dipole interaction, similar to the one occurring due to effects of ion focusing in gas discharges. Influence of charge spatial inhomogeneity and fluctuations on the results of recovery is also discussed.
Magnetohydrodynamic structure of a plasmoid in fast reconnection in low-beta plasmas: Shock-shock interactions
Authors: Zenitani Seiji
Published: March 2015

The shock structure of a plasmoid in magnetic reconnection in low-beta plasmas is investigated by two-dimensional magnetohydrodynamic simulations. Using a high-accuracy code with unprecedented resolution, shocks, discontinuities, and their intersections are resolved and clarified. Contact discontinuities emanate from triple-shock intersection points, separating fluids of different origins. Shock-diamonds inside the plasmoid appear to decelerate a supersonic flow. New shock-diamonds and a slow expansion fan are found inside the Petschek outflow. A sufficient condition for the new shock-diamonds and the relevance to astrophysical jets are discussed.
Electric field tunability of microwave soft magnetic properties of Co2FeAl Heusler alloy film
Authors: Li Shandong , Xu Jie , Xue Qian , Du Honglei , Li Qiang , Chen Caiyun , Yang Ru , Xie Shiming , Liu Ming , Nan Tianxiang , Sun Nian X. , Shao Weiquan
Published: March 2015

Co2FeAl Heusler alloy film with 100 nm in thickness was sputtered on (011)-cut lead zinc niobate-lead titanate (PZN-PT) single crystal slabs. It was revealed that this multiferroic laminate shows very large electric field (E-field) tunability of microwave soft magnetic properties. With the increase of electric field from 0 to 8 kV/cm on PZN-PT, the anisotropy field, HK, of the Co2FeAl film along [100] direction of PZN-PT is dramatically enhanced from 65 to 570 Oe due to the strong magnetoelectric (ME) coupling between ferromagnetic Co2FeAl film and ferroelectric substrate. At the same time, the damping constant α of Co2FeAl film dramatically decreases from 0.20 to 0.029. As a result, a significantly shift of self-biased ferromagnetic resonance frequency, fFMR, from 1.86 to 6.68 GHz with increment of 3.6 times was obtained. These features demonstrate that Co2FeAl/PZN-PT multiferroic laminate is promising in fabrication of E-field tunable microwave components.
The influence of an MgO nanolayer on the planar Hall effect in NiFe films
Authors: Li Minghua , Zhao Zhiduo , Ma Lin , Yu Guoqiang , Lu Xiangan , Teng Jiao , Yu Guanghua , Zhou Wenping , Amiri Pedram Khalili , Wang Kang L.
Published: March 2015

The Planar Hall Effect (PHE) in NiFe films was studied using MgO as the buffer and capping layer to reduce the shunt effect. The thermal annealing was found to be effective in increasing the sensitivity. The sensitivity of the magnetic field reached as high as 865 V/AT in a MgO (3 nm)/NiFe (5 nm)/MgO(3 nm)/Ta(3 nm) structure after annealing at 500 °C for 2 h, which is close to the sensitivity of semiconductor Hall Effect (HE) sensors. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) were used to study the sample. The results show that the top crystallization of MgO and NiFe (111) texture were improved by proper annealing. The smooth and clear bottom MgO/NiFe and top NiFe/MgO interface is evident from our data. In addition, the shunt current of Ta was decreased. These combined factors facilitate the improvement of the sensitivity of the magnetic field.
Stretchable nanocomposite electrodes with tunable mechanical properties by supersonic cluster beam implantation in elastomers
Authors: Borghi F. , Melis C. , Ghisleri C. , Podestà A. , Ravagnan L. , Colombo L. , Milani P.
Published: March 2015

We demonstrate the fabrication of gold-polydimethylsiloxane nanocomposite electrodes, by supersonic cluster beam implantation, with tunable Young's modulus depending solely on the amount of metal clusters implanted in the elastomeric matrix. We show both experimentally and by atomistic simulations that the mechanical properties of the nanocomposite can be maintained close to that of the bare elastomer for significant metal volume concentrations. Moreover, the elastic properties of the nanocomposite, as experimentally characterized by nanoindentation and modeled with molecular dynamics simulations, are also well described by the Guth-Gold classical model for nanoparticle-filled rubbers, which depends on the presence, concentration, and aspect ratio of metal nanoparticles, and not on the physical and chemical modification of the polymeric matrix due to the embedding process. The elastic properties of the nanocomposite can therefore be determined and engineered a priori, by controlling only the nanoparticle concentration.
Hydroquinone-ZnO nano-laminate deposited by molecular-atomic layer deposition
Authors: Huang Jie , Lucero Antonio T. , Cheng Lanxia , Hwang Hyeon Jun , Ha Min-Woo , Kim Jiyoung
Published: March 2015

In this study, we have deposited organic-inorganic hybrid semiconducting hydroquinone (HQ)/zinc oxide (ZnO) superlattices using molecular-atomic layer deposition, which enables accurate control of film thickness, excellent uniformity, and sharp interfaces at a low deposition temperature (150 °C). Self-limiting growth of organic layers is observed for the HQ precursor on ZnO surface. Nano-laminates were prepared by varying the number of HQ to ZnO cycles in order to investigate the physical and electrical effects of different HQ to ZnO ratios. It is indicated that the addition of HQ layer results in enhanced mobility and reduced carrier concentration. The highest Hall mobility of approximately 2.3 cm2/V·s and the lowest n-type carrier concentration of approximately 1.0 × 1018/cm3 were achieved with the organic-inorganic superlattice deposited with a ratio of 10 ZnO cycles to 1 HQ cycle. This study offers an approach to tune the electrical transport characteristics of ALD ZnO matrix thin films using an organic dopant. Moreover, with organic embedment, this nano-laminate material may be useful for flexible electronics.
Changes in the feather-free body of broiler breeder hens after sexual maturity
Authors: Nonis M. K. , Gous R. M.
Published: March 2015

Changes in the feather-free body (water, lipid and protein) of broiler breeder hens was measured at intervals between 15 and 60 weeks of age to provide information that could be used as the basis for predicting their maintenance requirements. The mean weight of feather-free body protein varied between 348 and 379 g at 15–20 weeks, increasing to 648 g by 40 weeks and then remaining relatively constant for the rest of the laying period. Mean body lipid content increased from 160 g at 15 weeks to 711 g at 60 weeks. The initial increase in feather-free body protein weight can be ascribed to increases in ovary and oviduct weights as the birds become sexually mature, and to the variation in ages at which this development takes place. Our conclusion is that changes in bodyweight in broiler breeders after sexual maturity are mainly in body lipid content, this being a consequence of the way in which the birds are fed, and that any gain in body and feather protein occurs only in hens that are out of lay. We suggest that it should not be necessary to assume that protein and lipid growth is obligatory when determining nutrient requirements of broiler breeder hens.
Voltammetric study of an FeS layer on a Hg electrode in supersaturated FeS chloride solution
Authors: Krznarić D. , Ciglenečki I.
Published: March 2015

Environmental context
During the electrochemical analysis of natural waters, the Hg electrode could become the site for surface metal sulfide formation, such as FeS, which can have significant influence on the voltammetric determination of FeII. Reduction of FeII in such conditions can occur both on the bare Hg surface and on the FeS-modified Hg surface. Until recently, measurements of FeII have considered only the signal obtained from reduction on the bare Hg surface, and hence may have underdetermined the true FeII content of natural samples.

Abstract
Cyclic voltammetry at a Hg electrode was used for the study of an FeS layer formed on the electrode surface during scanning potential in a saturated FeS suspension containing FeS nanoparticles in chloride electrolyte. Newly presented results as a part of comprehensive study on FeS electrochemistry in model and natural samples confirm that the voltammetric peak at –1.1V, which can often be recorded in anoxic waters containing Fe and sulfide species, represents reduction of Fe2+ on the Hg electrode surface modified by the FeS layer. Fe0 deposited on such a modified Hg surface is reoxidisable, often producing two oxidation peaks situated between –0.8 and –0.6V (v. Ag/AgCl). These peaks represent two different Fe0 oxidation products, free Fe2+ and Fe2+ chloro complexes, FeCl+. By scanning the potential from –0.75V in the positive direction, an oxidation exchange peak of Hg and FeS at ~–0.45V occurs, which can be taken as a measure for FeS nanoparticles from bulk solution.
Route to thermalization in the
α
-Fermi–Pasta–Ulam system
Authors: Onorato Miguel , Vozella Lara , Proment Davide , Lvov Yuri V.
Published: March 2015

Significance

Despite the fact that more than 60 years have passed, the
α
-Fermi–Pasta–Ulam (FPU) system has not yet been fully understood. Their seminal work stimulated many interdisciplinary research topics in mathematics and physics like integrable systems, soliton theory, ergodic theory, and chaos. In this article, we theoretically investigate the original problem by applying the wave–wave interaction theory. By using this mathematical approach, we are able to explain why the emergence of equipartition requires very long times (inaccessible when the original numerical experiments were performed but nowadays recently observed using computer power). Our approach is general and can be used to attack other problems of weakly nonlinear dispersive waves.
The entropic contributions in vitamin B
12
enzymes still reflect the electrostatic paradigm
Authors: Schopf Patrick , Mills Matthew J. L. , Warshel Arieh
Published: March 2015

Significance

The origin of the catalytic power of B
12
enzymes has been a major puzzle despite our previous finding that this effect is due to electrostatic stabilization of the leaving group. Recent findings of very large entropic contributions to catalysis were presented as an alternative to the electrostatic idea. Here, we use our ability to evaluate entropic contributions by the restraint release (RR) approach to reexamine the nature of the catalytic effect. The RR approach reproduces the observed entropic contributions to the activation barrier and demonstrates that the entropic effect is due to the previously identified electrostatic factors. Thus, we have further substantiated our paradigm for the origin of the catalytic power of B
12
enzymes.
The benefits of resource discovery for publishers: a librarian's view
Authors: STONE Graham
Published: March 2015

A core goal of librarians is to maximize usage of the content to which their libraries subscribe. Webscale or resource discovery systems offer a single search box for library users to access subscribed content. This article examines usage data at the University of Huddersfield to show how resource discovery has helped to increase the usage of publisher content that has been made available to discovery vendors, and considers the implications for publishers who are yet to do this. The article concludes that resource discovery systems have effectively levelled the playing field, allowing small to medium‐sized publishers to make content discoverable to users, and encourages publishers who do not have their content indexed in resource discovery systems to speak to discovery service vendors in order to do so at the earliest opportunity.
Book reviews
Authors: Watkinson Anthony
Published: March 2015

The Future of the Academic Journal, 2nd edn Bill Cope and Angus Phillips (eds) Amsterdam, Chandos an imprint of Elsevier, 2014, xxviii + 449pp. 978‐1‐84334‐783‐5 print (pbk) £52.50; 978‐1‐78063‐464‐7 (online) £52.50
Vertical limits of graph domains
Authors: Hakobyan Hrant , Šarić Dragomir
Published: March 2015

We consider the limiting behavior of Teichmüller geodesics in the universal Teichmüller space

T
(

H

)

T(\mathbb {H})

. Our main result states that the limits of the Teichmüller geodesics in the Thurston’s boundary of

T
(

H

)

T(\mathbb {H})

may depend on both vertical and horizontal foliation of the corresponding holomorphic quadratic differential.
EW_dmGWAS: edge-weighted dense module search for genome-wide association studies and gene expression profiles
Authors: Wang Quan , Yu Hui , Zhao Zhongming , Jia Peilin
Published: March 2015

Summary: We previously developed dmGWAS to search for dense modules in a human protein–protein interaction (PPI) network; it has since become a popular tool for network-assisted analysis of genome-wide association studies (GWAS). dmGWAS weights nodes by using GWAS signals. Here, we introduce an upgraded algorithm, EW_dmGWAS, to boost GWAS signals in a node- and edge-weighted PPI network. In EW_dmGWAS, we utilize condition-specific gene expression profiles for edge weights. Specifically, differential gene co-expression is used to infer the edge weights. We applied EW_dmGWAS to two diseases and compared it with other relevant methods. The results suggest that EW_dmGWAS is more powerful in detecting disease-associated signals.

Availability and implementation: The algorithm of EW_dmGWAS is implemented in the R package dmGWAS_3.0 and is available at http://bioinfo.mc.vanderbilt.edu/dmGWAS.

Contact:  zhongming.zhao@vanderbilt.edu or peilin.jia@vanderbilt.edu

Supplementary information:  Supplementary materials are available at Bioinformatics online.
Animal personality as a cause and consequence of contest behaviour
Authors: Briffa Mark , Sneddon Lynne U. , Wilson Alastair J.
Published: March 2015

We review the evidence for a link between consistent among-individual variation in behaviour (animal personality) and the ability to win contests over limited resources. Explorative and bold behaviours often covary with contest behaviour and outcome, although there is evidence that the structure of these ‘behavioural syndromes' can change across situations. Aggression itself is typically repeatable, but also subject to high within-individual variation as a consequence of plastic responses to previous fight outcomes and opponent traits. Common proximate mechanisms (gene expression, endocrine control and metabolic rates) may underpin variation in both contest behaviour and general personality traits. Given the theoretical links between the evolution of fighting and of personality, we suggest that longitudinal studies of contest behaviour, combining behavioural and physiological data, would be a useful context for the study of animal personalities.
The dynamic balance of import and export of zinc in
Escherichia coli
suggests a heterogeneous population response to stress
Authors: Takahashi Hiroki , Oshima Taku , Hobman Jon L. , Doherty Neil , Clayton Selina R. , Iqbal Mudassar , Hill Philip J. , Tobe Toru , Ogasawara Naotake , Kanaya Shigehiko , Stekel Dov J.
Published: March 2015

Zinc is essential for life, but toxic in excess. Thus all cells must control their internal zinc concentration. We used a systems approach, alternating rounds of experiments and models, to further elucidate the zinc control systems in
Escherichia coli
. We measured the response to zinc of the main specific zinc import and export systems in the wild-type, and a series of deletion mutant strains. We interpreted these data with a detailed mathematical model and Bayesian model fitting routines. There are three key findings: first, that alternate, non-inducible importers and exporters are important. Second, that an internal zinc reservoir is essential for maintaining the internal zinc concentration. Third, our data fitting led us to propose that the cells mount a heterogeneous response to zinc: some respond effectively, while others die or stop growing. In a further round of experiments, we demonstrated lower viable cell counts in the mutant strain tested exposed to excess zinc, consistent with this hypothesis. A stochastic model simulation demonstrated considerable fluctuations in the cellular levels of the ZntA exporter protein, reinforcing this proposal. We hypothesize that maintaining population heterogeneity could be a bet-hedging response allowing a population of cells to survive in varied and fluctuating environments.
Elucidating the significance of spatial memory on movement decisions by African savannah elephants using state–space models
Authors: Polansky Leo , Kilian Werner , Wittemyer George
Published: March 2015

Spatial memory facilitates resource acquisition where resources are patchy, but how it influences movement behaviour of wide-ranging species remains to be resolved. We examined African elephant spatial memory reflected in movement decisions regarding access to perennial waterholes. State–space models of movement data revealed a rapid, highly directional movement behaviour almost exclusively associated with visiting perennial water. Behavioural change point (BCP) analyses demonstrated that these goal-oriented movements were initiated on average 4.59 km, and up to 49.97 km, from the visited waterhole, with the closest waterhole accessed 90% of the time. Distances of decision points increased when switching to different waterholes, during the dry season, or for female groups relative to males, while selection of the closest waterhole decreased when switching. Overall, our analyses indicated detailed spatial knowledge over large scales, enabling elephants to minimize travel distance through highly directional movement when accessing water. We discuss the likely cognitive and socioecological mechanisms driving these spatially precise movements that are most consistent with our findings. By applying modern analytic techniques to high-resolution movement data, this study illustrates emerging approaches for studying how cognition structures animal movement behaviour in different ecological and social contexts.
Arabidopsis RIC1 Severs Actin Filaments at the Apex to Regulate Pollen Tube Growth
Authors: Zhou Zhenzhen , Shi Haifan , Chen Binqing , Zhang Ruihui , Huang Shanjin , Fu Ying
Published: March 2015

Pollen tubes deliver sperms to the ovule for fertilization via tip growth. The rapid turnover of F-actin in pollen tube tips plays an important role in this process. In this study, we demonstrate that Arabidopsis  thaliana RIC1, a member of the ROP-interactive CRIB motif-containing protein family, regulates pollen tube growth via its F-actin severing activity. Knockout of RIC1 enhanced pollen tube elongation, while overexpression of RIC1 dramatically reduced tube growth. Pharmacological analysis indicated that RIC1 affected F-actin dynamics in pollen tubes. In vitro biochemical assays revealed that RIC1 directly bound and severed F-actin in the presence of Ca2+ in addition to interfering with F-actin turnover by capping F-actin at the barbed ends. In vivo, RIC1 localized primarily to the apical plasma membrane (PM) of pollen tubes. The level of RIC1 at the apical PM oscillated during pollen tube growth. The frequency of F-actin severing at the apex was notably decreased in ric1-1 pollen tubes but was increased in pollen tubes overexpressing RIC1. We propose that RIC1 regulates F-actin dynamics at the apical PM as well as the cytosol by severing F-actin and capping the barbed ends in the cytoplasm, establishing a novel mechanism that underlies the regulation of pollen tube growth.
High-pressure protein crystallography of hen egg-white lysozyme
Authors: Yamada Hiroyuki , Nagae Takayuki , Watanabe Nobuhisa
Published: March 2015

Crystal structures of hen egg-white lysozyme (HEWL) determined under pressures ranging from ambient pressure to 950 MPa are presented. From 0.1 to 710 MPa, the molecular and internal cavity volumes are monotonically compressed. However, from 710 to 890 MPa the internal cavity volume remains almost constant. Moreover, as the pressure increases to 950 MPa, the tetragonal crystal of HEWL undergoes a phase transition fromP43212 toP43. Under high pressure, the crystal structure of the enzyme undergoes several local and global changes accompanied by changes in hydration structure. For example, water molecules penetrate into an internal cavity neighbouring the active site and induce an alternate conformation of one of the catalytic residues, Glu35. These phenomena have not been detected by conventional X-ray crystal structure analysis and might play an important role in the catalytic activity of HEWL.
Structure ofArabidopsis thalianaRubisco activase
Authors: Hasse Dirk , Larsson Anna M. , Andersson Inger
Published: March 2015

The CO2-fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is inactivated by the formation of dead-end complexes with inhibitory sugar phosphates. In plants and green algae, the ATP-dependent motor protein Rubisco activase restores catalytic competence by facilitating conformational changes in Rubisco that promote the release of the inhibitory compounds from the active site. Here, the crystal structure of Rubisco activase fromArabidopsis thalianais presented at 2.9 Å resolution. The structure reveals an AAA+ two-domain structure. More than 100 residues in the protein were not visible in the electron-density map owing to conformational disorder, but were verified to be present in the crystal by mass spectrometry. Two sulfate ions were found in the structure. One was bound in the loop formed by the Walker A motif at the interface of the domains. A second sulfate ion was bound at the N-terminal end of the first helix of the C-terminal domain. The protein packs in a helical fashion in the crystal, as observed previously for Rubisco activase, but differences in the helical pitch indicate flexibility in the packing of the protein.
The crystal structure of phosphorylated MAPK13 reveals common structural features and differences in p38 MAPK family activation
Authors: Yurtsever Zeynep , Scheaffer Suzanne M. , Romero Arthur G. , Holtzman Michael J. , Brett Tom J.
Published: March 2015

The p38 MAP kinases (p38 MAPKs) represent an important family centrally involved in mediating extracellular signaling. Recent studies indicate that family members such as MAPK13 (p38δ) display a selective cellular and tissue expression and are therefore involved in specific diseases. Detailed structural studies of all p38 MAPK family members are crucial for the design of specific inhibitors. In order to facilitate such ventures, the structure of MAPK13 was determined in both the inactive (unphosphorylated; MAPK13) and active (dual phosphorylated; MAPK13/pTpY) forms. Here, the first preparation, crystallization and structure determination of MAPK13/pTpY are presented and the structure is compared with the previously reported structure of MAPK13 in order to facilitate studies for structure-based drug design. A comprehensive analysis of inactiveversusactive structures for the p38 MAPK family is also presented. It is found that MAPK13 undergoes a larger interlobe configurational rearrangement upon activation compared with MAPK14. Surprisingly, the analysis of activated p38 MAPK structures (MAP12/pTpY, MAPK13/pTpY and MAPK14/pTpY) reveals that, despite a high degree of sequence similarity, different side chains are used to coordinate the phosphorylated residues. There are also differences in the rearrangement of the hinge region that occur in MAPK14 compared with MAPK13 which would affect inhibitor binding. A thorough examination of all of the active (phosphorylated) and inactive (unphosphorylated) p38 MAPK family member structures was performed to reveal a common structural basis of activation for the p38 MAP kinase family and to identify structural differences that may be exploited for developing family member-specific inhibitors.
Elucidation of the crystal structure ofCoriolopsis caperatalaccase: restoration of the structure and activity of the native enzyme from the T2-depleted form by copper ions
Authors: Glazunova Olga A. , Polyakov Konstantin M. , Fedorova Tatyana V. , Dorovatovskii Pavel V. , Koroleva Olga V.
Published: March 2015

Laccases are members of a large family of multicopper oxidases that catalyze the oxidation of a wide range of organic and inorganic substrates accompanied by the reduction of dioxygen to water. A new laccase was isolated from the basidiomyceteCoriolopsis caperatastrain 0677 and its amino-acid sequence was determined. According to its physicochemical properties and spectroscopic features, the laccase fromC. caperatais a high redox-potential blue laccase. Attempts to crystallize the native enzyme were unsuccessful. The copper type 2-depleted (T2D) laccase was prepared and crystallized. The structure of T2D laccase fromC. caperatawas solved at 1.6 Å resolution, and attempts to reconstruct the T2 copper centre were performed using Cu+and Cu2+ions. The structure of T2D+Cu+laccase was solved at 1.89 Å resolution. It was shown that the T2D+Cu+laccase structure contained four copper ions in the active site. Reconstruction could not be achieved when the T2D laccase crystals were treated with CuSO4.
Perceptions of success in performance-based procurement
Authors: Duren Joop Van , Dorée André , Voordijk Hans
Published: March 2015

Purpose

– The purpose of this study is to analyse, from the perspective of agency theory, differences between client and contractor in their perceptions of changes in uncertainty and in inclination to opportunistic behaviour while using a performance-based procurement procedure. In agency theory, dealing appropriately with the uncertainty and opportunism that results from information asymmetry is an essential precondition for successful procurement.

Design/methodology/approach

– The procurement procedure analysed is the Performance Information Procurement System (PiPS). PiPS is a performance-based procurement method that uses historic performance information to select the expected best performing contractor. In a theoretical model, a PiPS is interpreted as a set of contractual and organisational safeguards. Through a survey, based on this model, the perceived effects of the PiPS safeguards for both clients and contractors are investigated.

Findings

– Both clients and contractors believe that applying PiPS introduces safeguards that reduce transaction uncertainty. The perceived changes in the discouragement to use opportunistic behaviour when using PiPS differ between client and contractor. Clients do not know and contractors are sceptical as to whether applying PiPS discourages opportunistic behaviour. This difference in perceptions can be explained by the often-traditional background of the two parties’ project teams and the existence of information asymmetry.

Originality/value

– This is one of the first studies to show that changes in the transaction environment in a performance-based procurement process are perceived differently by the client and the contractor. It is necessary to align the roles of both parties to avoid problems related to opportunistic behaviour.
The role of experience feedback channels in the continuous development of house-building platforms
Authors: Jansson Gustav , Lundkvist Robert , Olofsson Thomas
Published: March 2015

Purpose

– This paper aims to describe how the experience feedback (EF) from building projects contributes to product platform development in house-building companies. House-building companies seek improvements to decrease costs, improve flow and decrease variability. Industrialised concepts using predefinitions in product platforms have provided a way of storing and reusing knowledge in project-based house-building organisations. However, the innovation in platforms is mainly incremental and based on EF from implementations in projects.

Design/methodology/approach

– Qualitative data were gathered via interviews, archival studies and observations, and analysed to identify the underlying structures used to manage the incorporation of EF during platform development. Four different EF channels were studied at one Scandinavian house-builder. The data are explained using an analytical framework based on diffusion of innovation, product platforms and EF.

Findings

– EF is distributed over the value chain to improve the platform over time. By using multiple channels with differing contents, it is possible to balance client demands and variation with production efficiency. Platform development using feedback channels provides opportunities for double-loop learning. Operative work on projects and the strategic decisions made by developers continuously improve the platform through a combination of knowledge pull and push.

Originality/value

– A combination of different EF channels and strategies for developing knowledge pull are shown to be essential for the incremental development of product platforms in project-based house-building organisations. The development of product platforms requires a shift away from the construction industry’s dominant project focus towards a more product-oriented view of house-building. Integrating the design phase with the supply chain enables variety but also creates a need for continuous platform development.
Role and nature of systemic innovations in construction and real estate sector
Authors: Kahkonen Kalle
Published: March 2015

Purpose

– The paper aims to clarify the role of systemic innovations and the subsequent profound change these can have on the construction and real estate sectors. Systemic innovation as a concept has an inherent capability for viewing factors, actors and conditions as a system or several systems. This has a direct relevance in construction and real estate sector where operations are composed of temporary and continual networks of stakeholders and where the end products can be understood as systems.

Design/methodology/approach

– The paper builds additional viewpoints and interpretations on some recently completed research where sector wide innovation aspects and challenges have been studied. Two doctoral dissertations supervised by the author and an action research effort where innovative cellular building products were developed and implemented are presented.

Findings

– The paper provides insights about systemic innovations in the construction and real estate sectors. It presents research topics that explain further what is required for having successful systemic innovations.

Research limitations/implications

– This is a synthesis paper. The presented viewpoints and interpretations can be used as starting points for research, development and innovation actions.

Practical implications

– The paper presents starting points for companies and other service providers targeting new innovative products which have systemic implications.

Originality/value

– This paper explains the need and challenges of systemic innovations in the construction and real estate sectors.
Developing scenarios for the Norwegian travel industry 2025
Authors: Enger Anniken , Sandvik Kåre , Kildal Iversen Endre
Published: March 2015

Purpose

The Norwegian travel industry faces decline in important international tourism segments and needs an industry wide and future‐oriented strategy to face these challenges. Accordingly, a common understanding of future drivers and different scenarios for the industry is needed. The paper aims to discuss these issues.

Design/methodology/approach

Using the process of scenario analysis and drawing upon the involvement of the tourism industry, this paper describes the method, drivers, scenarios, and implications.

Findings

The research identified six important drivers with predictable outcomes: uneven global economic development, digitalization, climate change, consumer demand – return on time, centralization, and demography. The Norwegian economy and Norwegian politics were the two drivers that stood out as the most significant for the tourism industry, with a very uncertain outcome, and constituted the two axes of the scenarios. This resulted in four scenarios: Money Rules, The Urban Diamond, Opportunities for All, and Master Plan.

Practical implications

The four scenarios represent different economic value of international tourism in Norway. The Opportunities for All and Master Plan scenarios represent the greatest economic value for Norwegian tourism. They indicate great opportunities for tourism to become the “new oil” in Norway if the oil economy declines. The two scenarios differ with respect to the degree of governance control vs market liberalization. The scenarios will be used to identify implications and risks for different parts of the tourism industry, and to further explore how governance control and market liberalization may be combined.

Originality/value

The research identified six drivers which are significant for the Norwegian tourism industry. This resulted in four scenarios which are used to identify implications and risks for different parts of the industry.
Geopolitical drivers of future tourist flows
Authors: Webster Craig , Ivanov Stanislav
Published: March 2015

Purpose

The purpose of this paper is to investigate the major political and economic changes in the world and the likely impact that these changes will bring to tourism and hospitality industries.

Design/methodology/approach

The paper adopts a geopolitical perspective on the dynamics of tourist flows, stipulating that geopolitics has a major impact on the size, structure, and direction of these flows.

Findings

The paper identifies six geopolitical drivers of tourist flows in the future, namely: the fall of the American Empire, the rise of the BRIC and the PINE countries, increased global political instability, increased importance of regional supranational organisations, greater control of the individuals on a global scale, and the greater importance and power of corporations than national governments.

Originality/value

The paper critically evaluates the geopolitical drivers of tourist flows, their likely future development and the impact they have on tourism.
Tourism in Tomorrow's World, 23‐24 February 2014, Renaissance City Center Hotel Doha, Qatar
Authors: Oskam Jeroen , Karijomedjo Graciella
Published: March 2015

Purpose

The conference was dedicated to global changes in tourism and to their specific impact in the Gulf Corporation Council (GCC) region. The purpose of this paper is to summarize the discussions at the conference.

Design/methodology/approach

Summary and highlights of the conference papers.

Findings

This report summarizes the findings and recommendations discussed at the international “Tourism in Tomorrow's World” conference that took place in Doha, February 2014. The conference depicted global trends and developments to zoom in on specific opportunities for tourism development in the GCC area. In view of major events planned in the host country, event legacies were included as a special topic. Conference sessions were dedicated to investments in tourist attractions and hotels, the relation between education and industry and to cultural heritage and tourism. As a result of the conference strong opportunities for tourism development in Qatar and other GCC members were identified.

Originality/value

This has been the first international conference on long‐term tourism strategies in the GCC area. The underlying motivation was the growing awareness in the GCC area of the need for economic diversification and reduction of oil dependence. The conference coincided with the launch of the Qatar National Tourism Sector Strategy 2030.