bluuebunny/crossref_metadata_2025 huggingface dataset:
Fine-scale factors influence fire regimes in mixed-conifer forests on three high mountains in Mexico
Authors: Yocom Larissa L. , Fulé Peter Z. , Falk Donald A. , García-Domínguez Celia , Cornejo-Oviedo Eladio , Brown Peter M. , Villanueva-Díaz José , Cerano Julián , Montaño Citlali Cortés
Published: September 2014

We investigated the influence of broad- v. fine-scale factors on fire in an unusual landscape suitable for distinguishing the drivers of fire synchrony. Our study was conducted in the Sierra Madre Oriental mountain range, in north-eastern Mexico. We worked in nine sites on three parallel mountains that receive nearly identical broad-scale climatic influence, but between which fires are unlikely to spread. We collected and cross dated samples from 357 fire-scarred trees in nine sites in high-elevation mixed-conifer forests and identified fire dates. We used Jaccard similarity analysis to evaluate synchrony among sites and quantified relationships between climate and fire occurrence. Fires were historically frequent (mean fire interval ranged from 8 to 16 years in all sites) and dates of fire exclusion ranged from 1887 to 1962. We found low fire synchrony among the three mountains, indicating a strong influence of fine-scale factors on fire occurrence. Fire regime attributes were similar across mountains despite the independence of fire dates. La Niña events were associated with fire over time, although not significantly since the 1830s. Our results highlight the importance of scale in describing fire regimes and suggest that we can use fire history to understand controls on complex ecosystem processes and patterns.
Soft spots and their structural signature in a metallic glass
Authors: Ding Jun , Patinet Sylvain , Falk Michael L. , Cheng Yongqiang , Ma Evan
Published: September 2014

Significance

This work demonstrates a structure–property correlation in metallic glasses for the community of amorphous solids. It associates geometrically unfavored motifs, i.e., those most disordered local polyhedral packing structures in a metallic glass, with the soft spots defined from the vibrational modes and correlates them with shear transformation zones composed of atoms with large nonaffine displacements. The statistical correlation established thus ties together the heterogeneity inherent in the amorphous structure with the spatial heterogeneity in the mechanical (elastic and plastic) properties of a metallic glass.
Chloride channels in stellate cells are essential for uniquely high secretion rates in neuropeptide-stimulated
Drosophila
diuresis
Authors: Cabrero Pablo , Terhzaz Selim , Romero Michael F. , Davies Shireen A. , Blumenthal Edward M. , Dow Julian A. T.
Published: September 2014

Significance

Endocrine control of chloride shunt conductance in Malpighian tubules of many insects is mediated by kinin diuretic peptides, but the route for chloride transport is unknown. We use
Drosophila
transgenics, combined with physiology, imaging, electrophysiology, and transgenic chloride reporter technology, to show that a chloride channel (CLC) encoded by
ClC-a/CG31116
is uniquely localized to stellate cells and is essential for neuropeptide-stimulated, but not resting, levels of secretion. Therefore, we have resolved this issue in
Drosophila
; kinin stimulates chloride flux by a transcellular route that is confined to the stellate cells.
Recent progress in integration of III–V nanowire transistors on Si substrate by selective-area growth
Authors: Tomioka Katsuhiro , Fukui Takashi
Published: September 2014

We report on the recent progress in electronic applications using III–V nanowires (NWs) on Si substrates using the selective-area growth method. This method could align vertical III–V NWs on Si under specific growth conditions. Detailed studies of the III–V NW/Si heterointerface showed the possibility of achieving coherent growth regardless of misfit dislocations in the III–V/Si heterojunction. The vertical III–V NWs grown using selective-area growth were utilized for high performance vertical field-effect transistors (FETs). Furthermore, III–V NW/Si heterointerfaces with fewer misfit dislocations provided us with a unique band discontinuity with a new functionality that can be used for the application of tunnel diodes and tunnel FETs. These demonstrations could open the door to a new approach for creating low power switches using III–V NWs as building-blocks of future nanometre-scaled electronic circuits on Si platforms.
Enhanced sputtering and incorporation of Mn in implanted GaAs and ZnO nanowires
Authors: Johannes A , Noack S , Paschoal W , Kumar S , Jacobsson D , Pettersson H , Samuelson L , Dick K A , Martinez-Criado G , Burghammer M , Ronning C
Published: September 2014

We simulated and experimentally investigated the sputter yield of ZnO and GaAs nanowires, which were implanted with energetic Mn ions at room temperature. The resulting thinning of the nanowires and the dopant concentration with increasing Mn ion fluency were measured by accurate scanning electron microscopy (SEM) and nano-x-Ray Fluorescence (nanoXRF) quantification, respectively. We observed a clearly enhanced sputter yield for the irradiated nanowires compared to bulk, which is also corroborated by iradina simulations. These show a maximum if the ion range matches the nanowire diameter. As a consequence of the erosion thinning of the nanowire, the incorporation of the Mn dopants is also enhanced and increases non-linearly with increasing ion fluency.
Diameter-dependent morphology of vapour–solid–solid grown ZnSe nanowires
Authors: Zannier V , Grillo V , Rubini S
Published: September 2014

We report on the growth of ZnSe nanowires by molecular beam epitaxy using solid Au nanoparticles as growth seeds. We show that nanowires with diameter below 15 nm are reproducibly straight, while thicker nanowires display a ‘worm-like’ morphology characterized by multiple kinks. This size-dependent morphology does not depend on growth parameters such as substrate temperature, Zn/Se pressure ratio or substrate chemistry, but we believe it is related to the solid state of the metal seed driving the nanowire growth. We finally propose three alternative methods to selectively obtain thin, straight and oriented ZnSe nanowires on GaAs(1 1 1)B.
3C–SiC nanowires luminescence enhancement by coating with a conformal oxides layer
Authors: Fabbri Filippo , Rossi Francesca , Lagonegro Paola , Negri Marco , Ponraj Joice Sophia , Bosi Matteo , Attolini Giovanni , Salviati Giancarlo
Published: September 2014

In this work, we report the light emission properties of different classes of 3C–SiC nanowires. We compare the luminescence of core/shell nanowires where the 3C–SiC core is covered by a SiO
x
shell of different thickness, or coated with different conformal oxide layers (aluminium oxide and gallium oxide), grown by atomic layer deposition. The main result is the enhancement of the 3C–SiC near-band-edge emission at room temperature with the nanowires surface coating, due to carrier's diffusion from the shell to the core, promoted by the alignment between the oxides and SiC bands in a type I quantum-well.
Optical properties of vertical, tilted and in-plane GaN nanowires on different crystallographic orientations of sapphire
Authors: Tessarek C , Figge S , Gust A , Heilmann M , Dieker C , Spiecker E , Christiansen S
Published: September 2014

Self-catalysed and self-organized GaN nanowires were grown on c-, a-, m- and r-plane sapphire by metal-organic vapour phase epitaxy. In dependence on the crystallographic orientation of the sapphire substrate, vertical, tilted and in-plane GaN nanowires were achieved. The nanowire orientation is visualized by scanning electron microscopy and analysed by x-ray diffraction. The influence of the sapphire nitridation step on the nanowire formation is investigated. Spatially and spectrally resolved cathodoluminescence studies are carried out on the GaN nanowires to analyse the influence of the GaN nanowire orientation as well as the presence of both N- and Ga-polar sections in a single nanowire on the optical properties.
Taming excitons in II–VI semiconductor nanowires and nanobelts
Authors: Xu Xinlong , Zhang Qing , Zhang Jun , Zhou Yixuan , Xiong Qihua
Published: September 2014

Excitons are one of the most important fundamental quasi-particles, and are involved in a variety of processes forming the basis of a wide range of opto-electronic and photonic devices based on II–VI semiconductor nanowires and nanobelts, such as light-emitting diodes, photovoltaic cells, photodetectors and nanolasers. A clear understanding of their properties and unveiling the potential engineering for excitons is of particular importance for the design and optimization of nanoscale opto-electronic and photonic devices. Herein, we present a comprehensive review on discussing the fundamental behaviours of the excitons in one-dimensional (1D) II–VI semiconductor nanomaterials (nanowires and nanobelts). We will start with a focus on the unique properties (origin, generation, etc) and dynamics of excitons and exciton complexes in the II–VI semiconductor nanowires and nanobelts. Then we move to the recent progress on the excitonic response in 1D nanomaterials and focus on the tailoring and engineering of excitonic properties through rational controlling of the physical parameters and conditions, intrinsically and extrinsically. These include (1) exciton–exciton interaction, which is important for 1D nanomaterial nanolasing; (2) exciton–phonon interaction, which has interesting applications for laser cooling; and (3) exciton–plasmon interaction, which is the cornerstone towards the realization of plasmonic lasers. The potential of electric field, morphology and size control for excitonic properties is also discussed. Unveiling and controlling excitonic properties in II–VI semiconductor nanowires and nanobelts would promote the development of 1D nanoscience and nanotechnology.
Localization and defects in axial (In,Ga)N/GaN nanowire heterostructures investigated by spatially resolved luminescence spectroscopy
Authors: Lähnemann Jonas , Hauswald Christian , Wölz Martin , Jahn Uwe , Hanke Michael , Geelhaar Lutz , Brandt Oliver
Published: September 2014

(In,Ga)N insertions embedded in self-assembled GaN nanowires (NWs) are of current interest for applications in solid-state light emitters. Such structures exhibit a notoriously broad emission band. We use cathodoluminescence spectral imaging in a scanning electron microscope and micro-photoluminescence spectroscopy on single NWs to learn more about the mechanisms underlying this emission. We observe a shift of the emission energy along the stack of six insertions within single NWs that may be explained by compositional pulling. Our results also corroborate reports that the localization of carriers at potential fluctuations within the insertions plays a crucial role for the luminescence of these NW based emitters. Furthermore, we resolve contributions from both structural and point defects in our measurements.
Polarization features of optically pumped CdS nanowire lasers
Authors: Röder Robert , Ploss Daniel , Kriesch Arian , Buschlinger Robert , Geburt Sebastian , Peschel Ulf , Ronning Carsten
Published: September 2014

High quality CdS nanowires suspended in air were optically pumped both below and above the lasing threshold. The polarization of the pump laser was varied while emission out of the end facet of the nanowire was monitored in a ‘head-on’ measurement geometry. Highest pump-efficiency and most efficient absorption of the pump radiation are demonstrated for an incident electric field being polarized parallel to the nanowire axis. This polarization dependence, which was observed both above the lasing threshold and in the regime of amplified spontaneous emission, is caused by an enhanced absorption for parallel polarized optical pumping. Measured Stokes parameters of the nanowire emission reveal that due to the onset of lasing the degree of polarization rapidly increases from approximately 15 to 85%. Both Stokes parameters and degree of polarization of the nanowire lasing emission are independent of the excitation polarization. The transversal lasing mode is therefore not notably affected by the polarization of the pumping beam, although the supply with optical gain is significantly enhanced for an excitation polarization parallel to the nanowire axis.
Gate modulation of below-band-gap photoconductivity in ZnO nanowire field-effect-transistors
Authors: Cammi Davide , Röder Robert , Ronning Carsten
Published: September 2014

We investigated the modulation of the photoconductivity under below-band gap excitation in single ZnO nanowire field effect transistors. Light excitation at 550 nm does not induce any change in the drain–source current when the gate voltage is kept at V
gs = 0 V, but results in a current increase when it is set to V
gs = −50 V. At this negative value of the gate voltage we further investigated the photo-reaction in the below-band-gap range 400–800 nm, observing a qualitative similar profile for all the photo-current curves. These results were attributed to a local effect, suggesting that the change in conductivity is due to the release of electrons from interface states located between the ZnO nanowire active channel and the gate dielectric SiO2.
Electrostatic spin control in multi-barrier nanowires
Authors: Rossella Francesco , Ercolani Daniele , Sorba Lucia , Beltram Fabio , Roddaro Stefano
Published: September 2014

We demonstrate that a consistent breakdown of the standard even–odd filling scheme in the Coulomb blockade regime can be easily obtained in a quantum dot containing two wells strongly coupled by a very transparent barrier. By exploiting a multi-gate configuration, we prove that a partial filling of nearly degenerate orbitals can be controlled electrostatically. Singlet–triplet spin transitions are demonstrated by low-temperature magneto-transport measurements.
Improved efficiency in organic/inorganic hybrid solar cells by interfacial modification of ZnO nanowires with small molecules
Authors: Chang Sehoon , Park Hyesung , Cheng Jayce J , Rekemeyer Paul H , Gradečak Silvija
Published: September 2014

We demonstrate improved photovoltaic performance of ZnO nanowire/poly(3-hexylthiophene) (P3HT) nanofiber hybrid devices using an interfacial modification of ZnO nanowires. Formation of cascade energy levels between the ZnO nanowire and P3HT nanofiber was achieved by interfacial modification of ZnO nanowires using small molecules tetraphenyldibenzoperiflanthene (DBP) and 3,4,9,10-perylenetetracarboxylic bisbenzimidazole (PTCBI). The successful demonstration of improved device performance owing to the cascade energy levels by small molecule modification is a promising approach toward highly efficient organic/inorganic hybrid solar cells.
Characterization and analysis of InAs/p–Si heterojunction nanowire-based solar cell
Authors: Mallorquí Anna Dalmau , Alarcón-Lladó Esther , Russo-Averchi Eleonora , Tütüncüoglu Gözde , Matteini Federico , Rüffer Daniel , Morral Anna Fontcuberta i
Published: September 2014

The growth of compound semiconductor nanowires on the silicon platform has opened many new perspectives in the area of electronics, optoelectronics and photovoltaics. We have grown a 1 × 1 mm2 array of InAs nanowires on p-type silicon for the fabrication of a solar cell. Even though the nanowires are spaced by a distance of 800 nm with a 3.3% filling volume, they absorb most of the incoming light resulting in an efficiency of 1.4%. Due to the unfavourable band alignment, carrier separation at the junction is poor. Photocurrent increases sharply at the surrounding edge with the silicon, where the nanowires do not absorb anymore. This is further proof of the enhanced absorption of semiconductors in nanowire form. This work brings further elements in the design of nanowire-based solar cells.
Magnetic properties, exchange coupling and novel stripe domains in bulk SrFe12O19/(Ni,Zn)Fe2O4 composites
Authors: Xia Ailin , Zuo Conghua , Zhang Lijiao , Cao Chunxiang , Deng Yong , Xu Wei , Xie Mingfu , Ran Songlin , Jin Chuangui , Liu Xianguo
Published: September 2014

Bulk SrFe12O19/(Ni0.4Zn0.6)Fe2O4 composite ferrites with mass ratios R
m = 2 : 1, 1 : 1 and 1 : 2 were prepared using nanopowders obtained via a hydrothermal method, and their phase composition, magnetic properties, exchange coupling (EC) and magnetic microstructures were systematically investigated. It is found that all the bulk specimens sintered at either 700 or 900 °C are composed of two phases but exhibit typical single-phase magnetic behaviours, indicating the existence of EC between the magnetically hard and soft phases. However, too much (R
m = 2 : 1) or too little (R
m = 1 : 2) soft (Ni0.4Zn0.6)Fe2O4 phase weakens the EC in the composites. It is also proved that except for the EC, the strengthening of chemical polarization of the internal chemical bonds affects saturation magnetization, and the size of nanoscale grains significantly influences the EC and magnetic properties. In addition, novel stripe domains are found in all of the bulk composite specimens, which could be ascribed to the magnetization of the soft (Ni,Zn)Fe2O4 phase induced by the hard SrFe12O19 phase.
β-Ga2O3 nanowires for an ultraviolet light selective frequency photodetector
Authors: López I , Castaldini A , Cavallini A , Nogales E , Méndez B , Piqueras J
Published: September 2014

The behaviour of β-Ga2O3 nanowires as photoconductive material in deep ultraviolet photodetectors to operate in the energy range 3.0–6.2 eV has been investigated. The nanowires were grown by a catalyst-free thermal evaporation method on gallium oxide substrates. Photocurrent measurements have been carried out on both undoped and Sn-doped Ga2O3 nanowires to evidence the influence of the dopant on the photodetector performances. The responsivity spectrum of single nanowires show maxima in the energy range 4.8–5.4 eV and a strong dependence on the pulse frequency of the excitation light has been observed for undoped nanowires. Our results show that the responsivity of β-Ga2O3 nanowires can be controlled by tuning the chopper frequency of the excitation light and/or by doping of the nanowires. Non-linear behaviour in characteristic current–voltage curves has been observed for Ga2O3 : Sn nanowires. The mechanism leading to this behaviour has been discussed and related to space-charged-limited current effects. In addition, the responsivity achieved by doped nanowires at lower bias is higher than for undoped ones.
Multi-species simulation of Trichel pulses in oxygen
Authors: Durán-Olivencia F J , Pontiga F , Castellanos A
Published: September 2014

The development of negative corona Trichel pulses in oxygen between a spherical cathode and a plane is investigated using a plasma chemical model of ten selected species, which includes electrons, ions and neutrals. The interaction among these species is described by a model that incorporates the most important plasma chemical processes, such as ionization, electron attachment and detachment, electron impact dissociation and excitation, and clustering. The spatio-temporal evolution of charged and neutral species and their reaction rates are evaluated along different moments during the pulses. The case of the first Trichel pulse is considered separately, since its characteristics clearly differ from the subsequent pulses. The results show that the negative space charge is constituted of different types of ions, depending on the stage of the pulse. Moreover, a spatial segregation of negative ions is observed during the post-pulse period. Regarding neutral species, ozone increases linearly with time, without being considerably affected by the occurrence of pulses.
The role of nanographitic phase on enhancing the electron field emission properties of hybrid granular structured diamond films: the electron energy loss spectroscopic studies
Authors: Kurian Joji , Sankaran Kamatchi Jothiramalingam , Thomas Joseph P , Tai N H , Chen Huang-Chin , Lin I-Nan
Published: September 2014

The electron field emission (EFE) properties of the hybrid granular structured diamond (HiD) films were markedly improved by N-ion implantation and annealing processes. The evolution of microstructure/bonding structure of the films due to these processes was investigated using the transmission electron microscopy (TEM) and the electron energy loss spectroscopy (EELS), respectively. The N-ion implanted/annealed HiD films showed a low turn-on field of (E
0)HiD = 7.4 V µm−1 with large current density of (J
e)HiD = 600 µA cm−2, at 17.8 V µm−1, compared with pristine HiD films ((E
0) = 10.3 V µm−1, (J
e) = 95 µA cm−2 at the same applied field). While the TEM studies revealed only the microstructural evolution due to N-ion implantation/annealing processes, the EELS elucidated the change in bonding structure, namely the transformation between the sp3-bonded carbons and the sp2-bonded ones. Therefore, the combined TEM/EELS analyses provided more insight into understand the mechanism by which the N-ion implantation/annealing processes enhanced the EFE properties of HiD films. These studies clearly demonstrated that the N-ion implantation/annealing processes induced the formation of nanographitic clusters. These nanographitic phases form an interconnected path throughout the film surface facilitating the easy transport of electrons and thereby markedly enhancing the EFE properties for the N implanted/annealed HiD films.
How Taxol/paclitaxel kills cancer cells
Authors: Weaver Beth A.
Published: September 2014

Taxol (generic name paclitaxel) is a microtubule-stabilizing drug that is approved by the Food and Drug Administration for the treatment of ovarian, breast, and lung cancer, as well as Kaposi's sarcoma. It is used off-label to treat gastroesophageal, endometrial, cervical, prostate, and head and neck cancers, in addition to sarcoma, lymphoma, and leukemia. Paclitaxel has long been recognized to induce mitotic arrest, which leads to cell death in a subset of the arrested population. However, recent evidence demonstrates that intratumoral concentrations of paclitaxel are too low to cause mitotic arrest and result in multipolar divisions instead. It is hoped that this insight can now be used to develop a biomarker to identify the ∼50% of patients that will benefit from paclitaxel therapy. Here I discuss the history of paclitaxel and our recently evolved understanding of its mechanism of action.
A unique kinesin-8 surface loop provides specificity for chromosome alignment
Authors: Kim Haein , Fonseca Cindy , Stumpff Jason
Published: September 2014

Microtubule length control is essential for the assembly and function of the mitotic spindle. Kinesin-like motor proteins that directly attenuate microtubule dynamics make key contributions to this control, but the specificity of these motors for different subpopulations of spindle microtubules is not understood. Kif18A (kinesin-8) localizes to the plus ends of the relatively slowly growing kinetochore fibers (K-fibers) and attenuates their dynamics, whereas Kif4A (kinesin-4) localizes to mitotic chromatin and suppresses the growth of highly dynamic, nonkinetochore microtubules. Although Kif18A and Kif4A similarly suppress microtubule growth in vitro, it remains unclear whether microtubule-attenuating motors control the lengths of K-fibers and nonkinetochore microtubules through a common mechanism. To address this question, we engineered chimeric kinesins that contain the Kif4A, Kif18B (kinesin-8), or Kif5B (kinesin-1) motor domain fused to the C-terminal tail of Kif18A. Each of these chimeric kinesins localizes to K-fibers; however, K-fiber length control requires an activity specific to kinesin-8s. Mutational studies of Kif18A indicate that this control depends on both its C-terminus and a unique, positively charged surface loop, called loop2, within the motor domain. These data support a model in which microtubule-attenuating kinesins are molecularly “tuned” to control the dynamics of specific subsets of spindle microtubules.
Traps and Thresholds in Pastoralist Mobility
Authors: Toth Russell
Published: September 2014

This article presents a new approach to identifying poverty traps in East African pastoralist communities. A flexible semiparametric estimation procedure is used to identify a bifurcation in the propensity to engage in the asset‐based, mobile herding livelihood, in comparison to the sedentary alternative, as a function of herd size. The identified threshold is consistent with previous evidence on poverty traps based on modeling herd stock dynamics. The approach contributes to an emerging literature that seeks to identify poverty traps through testing the implications of the posited behavioral mechanism behind the trap, as opposed to directly modeling asset dynamics. The approach is further employed to provide complementary evidence on the relationship between ability and assets in sustaining mobile pastoralism.
Death With Tuberculosis in California, 1994–2008
Authors: Pascopella Lisa , Barry Pennan M. , Flood Jennifer , DeRiemer Kathryn
Published: September 2014

Background.  Identifying factors associated with tuberculosis (TB) deaths will inform efforts to prevent deaths.

Methods.  We examined deaths among patients with culture-confirmed TB reported to the California TB Registry during 1994–2008. We calculated the age-adjusted percentage of deaths before and during TB treatment and estimated trends. We constructed multivariable logistic regression models to identify factors associated with death during treatment.

Results.  Of 40 125 patients with culture-confirmed TB, 4565 (11%) died: 1146 (25%) died before treatment started, and 3419 (75%) died during treatment. The age-adjusted percentage of patients who died before and during treatment declined from 1994 to 2008 (3.5% to 2%, and 10.4% to 7.2%, respectively, both P < .0001). We identified several risk factors for death that may be addressed with public health efforts: acquired multidrug resistance (adjusted odds ratio [aOR] = 4.67; 95% confidence interval [CI], 2.09–10.45); care in the private sector (aOR = 3.08; 95% CI, 2.75–3.44); and an initial treatment regimen of <3 drugs (aOR = 2.07; 95% CI, 1.63–2.64). We identified other risk factors for death that could be used as markers for intensified diagnostic and treatment processes in hospital: human immunodeficiency virus coinfection; meningeal, peritoneal, and disseminated TB; substance use; and abnormal chest radiograph without cavities.

Conclusions.  In California, 1 in 9 TB patients died with a potentially curable disease. Public health departments might prevent deaths in patients with TB by strengthening partnerships with private providers, intensifying diagnostic and treatment processes for patients at risk of death in hospital, optimizing treatment regimens for patients with comorbidities, and preventing the acquisition of drug resistance.
Cell-based Therapy for Acute Organ Injury
Authors: Monsel Antoine , Zhu Ying-gang , Gennai Stephane , Hao Qi , Liu Jia , Lee Jae W.
Published: September 2014

Critically ill patients often suffer from multiple organ failures involving lung, kidney, liver, or brain. Genomic, proteomic, and metabolomic approaches highlight common injury mechanisms leading to acute organ failure. This underlines the need to focus on therapeutic strategies affecting multiple injury pathways. The use of adult stem cells such as mesenchymal stem or stromal cells (MSC) may represent a promising new therapeutic approach as increasing evidence shows that MSC can exert protective effects following injury through the release of promitotic, antiapoptotic, antiinflammatory, and immunomodulatory soluble factors. Furthermore, they can mitigate metabolomic and oxidative stress imbalance. In this work, the authors review the biological capabilities of MSC and the results of clinical trials using MSC as therapy in acute organ injuries. Although preliminary results are encouraging, more studies concerning safety and efficacy of MSC therapy are needed to determine their optimal clinical use. (Anesthesiology 2014; 121:1099-121)
The feasibility of coherent energy transfer in microtubules
Authors: Craddock Travis John Adrian , Friesen Douglas , Mane Jonathan , Hameroff Stuart , Tuszynski Jack A.
Published: September 2014

It was once purported that biological systems were far too ‘warm and wet’ to support quantum phenomena mainly owing to thermal effects disrupting quantum coherence. However, recent experimental results and theoretical analyses have shown that thermal energy may assist, rather than disrupt, quantum coherent transport, especially in the ‘dry’ hydrophobic interiors of biomolecules. Specifically, evidence has been accumulating for the necessary involvement of quantum coherent energy transfer between uniquely arranged chromophores in light harvesting photosynthetic complexes. The ‘tubulin’ subunit proteins, which comprise microtubules, also possess a distinct architecture of chromophores, namely aromatic amino acids, including tryptophan. The geometry and dipolar properties of these aromatics are similar to those found in photosynthetic units indicating that tubulin may support coherent energy transfer. Tubulin aggregated into microtubule geometric lattices may support such energy transfer, which could be important for biological signalling and communication essential to living processes. Here, we perform a computational investigation of energy transfer between chromophoric amino acids in tubulin via dipole excitations coupled to the surrounding thermal environment. We present the spatial structure and energetic properties of the tryptophan residues in the microtubule constituent protein tubulin. Plausibility arguments for the conditions favouring a quantum mechanism of signal propagation along a microtubule are provided. Overall, we find that coherent energy transfer in tubulin and microtubules is biologically feasible.
The effect of helium nano-bubbles on the structures stability and electronic properties of palladium tritides: a density functional theory study
Authors: Das N. K. , Rigby K. , de Leeuw N. H.
Published: September 2014

Density functional theory calculations have been used to study the incorporation of helium in perfect and defect-containing palladium tritides, where we have calculated the energetics of incorporation and the migration behaviour. Helium atoms preferably occupy the octahedral interstitial and substitutional sites in the perfect and Pd vacancy-containing tritides, respectively. The energetics reveal that helium clusters can form in the lattice, which displace the Pd metal atoms. The defective lattice shows less expansion compared with the perfect lattice, which can accommodate the helium less easily. The path from octahedral–tetrahedral–octahedral sites is the lowest energy pathway for helium diffusion, and the energetics indicate that the helium generated from tritium decay can accumulate in or near the octahedral sites. Density of states analyses shows the hybridization between palladium d and tritium s orbitals and repulsion between palladium d and helium s orbitals, which can distort the lattice as a result of generating localized stress.
In vitro activities of amphotericin B deoxycholate and liposomal amphotericin B against 604 clinical yeast isolates
Authors: Montagna Maria Teresa , Lovero Grazia , Coretti Caterina , De Giglio Osvalda , Martinelli Domenico , Bedini Andrea , Delia Mario , Rosato Antonio , Codeluppi Mauro , Caggiano Giuseppina
Published: September 2014

We determined the in vitro antifungal activity of liposomal amphotericin B (L-AmB) against 604 clinical yeast isolates. Amphotericin B deoxycholate (D-AmB) was tested in parallel against all the isolates. Susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) M27-A3 method. Overall, L-AmB was highly active against the isolates (mean MIC, 0.42 µg ml−1; MIC90, 1 µg ml−1; 97.2 % of MICs were ≤1 µg ml−1) and comparable to D-AmB (mean MIC, 0.48 µg ml−1; MIC90, 1 µg ml−1; 97.3 % of MICs were ≤1 µg ml−1). The in vitro activity of D-AmB and L-AmB was correlated (R
2 = 0.61; exp(b), 2.3; 95 % CI, 2.19–2.44, P<0.001). Candida albicans (mean MICs of D-AmB and L-AmB, 0.39 µg ml−1 and 0.31 µg ml−1, respectively) and Candida parapsilosis (mean MICs of D-AmB and L-AmB, 0.38 µg ml−1 and 0.35 µg ml−1, respectively) were the species most susceptible to the agents tested, while Candida krusei (currently named Issatchenkia orientalis) (mean MICs of D-AmB and L-AmB, 1.27 µg ml−1 and 1.13 µg ml−1, respectively) was the least susceptible. The excellent in vitro activity of L-AmB may have important implications for empirical treatment approaches and support its role in treatment of a wide range of invasive infections due to yeasts.
Paramyxovirus-based production of Rift Valley fever virus replicon particles
Authors: Wichgers Schreur Paul J. , Oreshkova Nadia , Harders Frank , Bossers Alex , Moormann Rob J. M. , Kortekaas Jeroen
Published: September 2014

Replicon-particle-based vaccines combine the efficacy of live-attenuated vaccines with the safety of inactivated or subunit vaccines. Recently, we developed Rift Valley fever virus (RVFV) replicon particles, also known as nonspreading RVFV (NSR), and demonstrated that a single vaccination with these particles can confer sterile immunity in target animals. NSR particles can be produced by transfection of replicon cells, which stably maintain replicating RVFV S and L genome segments, with an expression plasmid encoding the RVFV glycoproteins, Gn and Gc, normally encoded by the M-genome segment. Here, we explored the possibility to produce NSR with the use of a helper virus. We show that replicon cells infected with a Newcastle disease virus expressing Gn and Gc (NDV-GnGc) were able to produce high levels of NSR particles. In addition, using reverse genetics and site-directed mutagenesis, we were able to create an NDV-GnGc variant that lacks the NDV fusion protein and contains two amino acid substitutions in, respectively, Gn and HN. The resulting virus uses a unique entry pathway that facilitates the efficient production of NSR in a one-component system. The novel system provides a promising alternative for transfection-based NSR production.
Identification of an antigenic domain in the N-terminal region of avian hepatitis E virus (HEV) capsid protein that is not common to swine and human HEVs
Authors: Wang Lizhen , Sun Yani , Du Taofeng , Wang Chengbao , Xiao Shuqi , Mu Yang , Zhang Gaiping , Liu Lihong , Widén Frederik , Hsu Walter H. , Zhao Qin , Zhou En-Min
Published: September 2014

The antigenic domains located in the C-terminal 268 amino acid residues of avian hepatitis E virus (HEV) capsid protein have been characterized. This region shares common epitopes with swine and human HEVs. However, epitopes in the N-terminal 338 amino acid residues have never been reported. In this study, an antigenic domain located between amino acids 23 and 85 was identified by indirect ELISA using the truncated recombinant capsid proteins as coating antigens and anti-avian HEV chicken sera as primary antibodies. In addition, this domain did not react with anti-swine and human HEV sera. These results indicated that the N-terminal 338 amino acid residues of avian HEV capsid protein do not share common epitopes with swine and human HEVs. This finding is important for our understanding of the antigenicity of the avian HEV capsid protein. Furthermore, it has important implications in the selection of viral antigens for serological diagnosis.
Human herpesvirus 6 gM/gN complex interacts with v-SNARE in infected cells
Authors: Kawabata Akiko , Serada Satoshi , Naka Tetsuji , Mori Yasuko
Published: September 2014

Human herpesvirus 6 (HHV-6) glycoprotein M (gM) is an envelope glycoprotein that associates with glycoprotein N (gN), forming the gM/gN protein complex, in a similar manner to the other herpesviruses. Liquid chromatography-MS/MS analysis showed that the HHV-6 gM/gN complex interacts with the v-SNARE protein, vesicle-associated membrane protein 3 (VAMP3). VAMP3 colocalized with the gM/gN complex at the trans-Golgi network and other compartments, possibly the late endosome in HHV-6-infected cells, and its expression gradually increased during the late phase of virus infection. Finally, VAMP3 was incorporated into mature virions and may be transported with the gM/gN complex.
Seitz symbols for symmetry operations of subperiodic groups
Authors: Litvin Daniel B. , Kopský Vojtech
Published: September 2014

Recently adopted International Union of Crystallography conventions for the notation of Seitz symbols of symmetry operations require a revision of the Seitz notation used inInternational Tables for CrystallographyVol. E,Subperiodic Groups. This paper gives the subperiodic group symmetry operations blocks of Vol. E with the Seitz symbol for each included symmetry operation in the recently adopted conventions for Seitz notation.
High-flux ptychographic imaging using the new 55 µm-pixel detector `Lambda' based on the Medipix3 readout chip
Authors: Wilke R. N. , Wallentin J. , Osterhoff M. , Pennicard D. , Zozulya A. , Sprung M. , Salditt T.
Published: September 2014

Suitable detection systems that are capable of recording high photon count rates with single-photon detection are instrumental for coherent X-ray imaging. The new single-photon-counting pixel detector `Lambda' has been tested in a ptychographic imaging experiment on solar-cell nanowires using Kirkpatrick–Baez-focused 13.8 keV X-rays. Taking advantage of the high count rate of the Lambda and dynamic range expansion by the semi-transparent central stop, a high-dynamic-range diffraction signal covering more than seven orders of magnitude has been recorded, which corresponds to a photon flux density of about 105 photons nm−2 s−1or a flux of ∼1010 photons s−1on the sample. By comparison with data taken without the semi-transparent central stop, an increase in resolution by a factor of 3–4 is determined: from about 125 nm to about 38 nm for the nanowire and from about 83 nm to about 21 nm for the illuminating wavefield.
Factors governing filling of blind via and through hole in electroplating
Authors: Wang Jing , Wu Miao , Cui Chengqiang
Published: September 2014

Purpose

– The purpose of this paper is to present a clear picture of the key factors of blind via and through hole filling in electroplating, e.g. shape of via or hole, electroplating solution, process, as well as the developments of mechanisms and models.

Design/methodology/approach

– First, the paper details the development trends and challenges of via filling. Then the research status of mechanisms, electroplating solutions, including base solution and additives, numerical model and mass transfer is described. Finally, through hole filling is briefly reviewed.

Findings

– To achieve excellent via filling performance, the characteristics of the via or hole, the ratio of acid/copper, selection of additives and factors of mass transfer are comprehensively considered in terms of optimization of the electroplating process. It is beneficial to design vias with appropriate aspect ratios, to strengthen the adsorption of the accelerator in the via bottom, to inhibit the increase of surface copper thickness and to form butterfly-shaped copper in the centre of through holes. Optimized process parameters should be taken into consideration in superfilling.

Originality/value

– The paper reviews different sets of additives, mechanisms and superfilling models for state-of-the-art via filling and the developments of filling for through holes.
Transformational leadership and innovative work behavior
Authors: Afsar Bilal , F. Badir Yuosre , Bin Saeed Bilal
Published: September 2014

Purpose

– The purpose of this paper is to explore the mediating role of psychological empowerment and the moderating role of self-construal (independent and interdependent) on the relationship between transformational leadership and employees’ innovative work behavior (IWB).

Design/methodology/approach

– A total of 639 followers and 87 leaders filled out questionnaires from cross-industry sample of five most innovative companies of China. Structural equation modeling was used to analyze the relations.

Findings

– Results revealed that psychological empowerment mediated the relationship between transformational leadership and IWB. The research established that transformational leadership positively influences IWB which includes idea generation as well as idea implementation. The results also showed that the relationship between transformational leadership and IWB was stronger among employees with a higher interdependent self-construal and a lower independent self-construal.

Originality/value

– This study adds to IWB literature by empirically testing the moderating role of self-construal and the mediating role of psychological empowerment on transformational leadership-IWB link.
Paper mill's distribution efficiency to emerging East European markets
Authors: Hilmola Olli-Pekka , Hämäläinen Esa , Hujala Maija
Published: September 2014

Purpose

– European paper industry has been struggling with margins and profitability for more than decade time period. At typical in markets of west, paper product demand is at long-term decline, mostly driven by continuously increasing internet use. However, in emerging markets demand still exists, and in Europe numerous small markets in east have even some growth available. The paper aims to discuss these issues.

Design/methodology/approach

– The authors analyse in this research work with longitudinal data (period of 2002-2009) from one large Finnish paper mill and data envelopment analysis (DEA) approach, how distribution efficiency to selected eight East European markets has evolved.

Findings

– In general distribution efficiency has improved, but this has taken place in step-wise manner rather than being linear year-to-year development (year 2006 found to be the threshold). Reason is mostly in better management of transportation costs, and in particular lower monthly deviation of these costs. It is surprising that case paper mill has been able to manage transportation costs in rapidly increasing energy cost environment so efficiently. Maybe European Union enlargement of 2004 and 2007 has had its effects on distribution efficiency.

Research limitations/implications

– The research is limited to the deliveries of one paper mill located in Finland. Also East European markets in the early periods of this study were emerging papers markets, and distribution practices were clearly evolving.

Practical implications

– Based on the study East European paper market distribution should give more attention on transportation cost control, and trying to find solutions to minimize it with low monthly fluctuation.

Originality/value

– Very few studies exist from East European distribution issues, and particularly that of paper industry. Also used quantitative method of DEA is relatively new in this context and gives valuable insights for the distribution efficiency development.
Innovation in agro-food chain
Authors: Caiazza Rosa , Volpe Tiziana , Audretsch David
Published: September 2014

Purpose

– The purpose of this paper is to offer a new perspective on innovation in agro-food industry. Innovations in the agro-food industry depend on multiple forces interacting with each other under specific rules to create new ways to deal with social or economic processes. The relevance of this topic for the whole economy leads the authors to investigate main drivers of innovation in agro-food system.

Design/methodology/approach

– The authors provide a framework that considers the role of policies, actors and activities for innovation in the agro-food industry and tests its validity on the Campanian tomato sub-system.

Findings

– The authors’ framework applied to Campanian tomato sub-system shows the role of institutions, actors and activities in promoting innovation in agro-food system.

Originality/value

– The paper offers a new perspective on innovation in agro-food industry.
Management of aggression care plans in a forensic intellectual disability service: a ten-year progress update
Authors: Kitchen David , Thomas Cathy , Chester Verity
Published: September 2014

Purpose

– Standardised approaches to the management of aggression and violence are critical for all stakeholders of intellectual disability services. The purpose of this paper is to describe the Management of Aggression Care Plan (MoACP). The care plan aims to reduce levels of restrictive interventions, to ensure any interventions relative to aggression and violence are the least restrictive possible, and to promote adaptive behaviours and support life enriching opportunities, in a manner which is personalised to the unique profiles of every patient.

Design/methodology/approach

– The MoACP was first described by Thomas et al. (2005). This paper describes the rationale, theoretical basis, structure and benefits of the care plan, and provides details of revisions made to the plan in response to evidence-based practice recommendations.

Findings

– The value of implementing a structured approach to the care planning of management of aggression and violence, in reducing the frequency and impact of restrictive practices, and promoting life enriching opportunities is described.

Practical implications

– The paper describes a number of practical features of the care plan which most support its continued effectiveness, including patient involvement, individual patient focused training, and audit.

Originality/value

– Although many services undertake localised approaches to the care planning of management of violence and aggression in forensic intellectual disability services, few have been described in the published literature.
Sentencing offenders with mental impairment: the case of arsonists with intellectual disability
Authors: Curtis Ashlee , McVilly Keith , Day Andrew
Published: September 2014

Purpose

– Offenders with intellectual disability (ID) who commit arson and other acts of fire setting are over-represented in the criminal justice system in Australia, as in many other jurisdictions. The purpose of this paper is to provide insight into the judicial considerations that influence sentencing in these cases.

Design/methodology/approach

– Case law was utilised to locate and analyse judges’ sentencing remarks for offenders with ID found guilty of an offence of arson. These data were subject to Inductive Content Analysis to establish the major judicial considerations in sentencing.

Findings

– Seven common issues emerged: general deterrence, seriousness of arson, rehabilitation, sentencing options, moral culpability, protection of the community, and punishment. Judges noted that they handed down reduced sentences to persons with ID relative to the severity of their offending, that they considered people with ID to have low levels of moral culpability, and that these offenders did not provide good examples for community deterrence.

Originality/value

– The current study highlights the need for judges to have available a range of sentencing options, including diversion and treatment/rehabilitation programmes for persons with ID, particularly for those involved in more serious offences such as arson.