bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychosoziale Belastungen zu verschiedenen Zeitpunkten nach Brandverletzung
Authors: Berg Lea , Meyer Stefanie , Ipaktchi Ramin , Vogt Peter , Müller Astrid , de Zwaan Martina
Published: September 2016

Brandverletzte leiden unter psychischen und sozialen Folgebeeinträchtigungen. In der vorliegenden Studie wurde geprüft, ob sich Patienten mit unterschiedlichen Zeitintervallen seit der Verbrennung im Hinblick auf psychosoziale Belastungen unterscheiden. Patienten, die in der Zeit zwischen 2006 und 2012 aufgrund einer Verbrennung stationär behandelt wurden, beantworteten Fragebögen zu Lebensqualität (Burn Specific Health Scale – Brief; BSHS-B), Angst und Depression (Hospital Anxiety and Depression Scale – Deutsche Version; HADS-D), posttraumatischer Belastungsstörung (PTBS, Impact of Event Scale – Revidierte Version; IES-R), Stigmatisierung (Perceived Stigmatization Questionnaire; PSQ) und sozialer Unterstützung (Fragebogen zur sozialen Unterstützung; F-SozU-7). Auf Basis der unterschiedlichen Zeiträume zwischen Unfall und Erhebungszeitpunkt der Daten fand eine Einteilung der Stichprobe (146 Patienten) in 4 Gruppen statt. Es zeigten sich keine signifikanten Unterschiede im Ausmaß der psychischen Belastung. Auch lagen keine Differenzen in soziodemografischen und verbrennungsspezifischen Merkmalen vor. Insgesamt lagen 18 (12,4%) Patienten im Bereich Angst und 22 (15,2%) Personen im Bereich Depression bei einem Cut-off von ≥11 im HADS. Ein Verdacht auf die Diagnose einer PTBS konnte bei 16 (11,1%) Patienten gestellt werden. Bezüglich laufender Psycho(pharmako)therapie und dem Wunsch nach Psychotherapie glichen sich die Gruppen. Die Ergebnisse deuten auf chronische psychische Beeinträchtigungen nach Verbrennungen hin. Psychosoziale Interventionen können daher auch noch mehrere Jahre nach der Brandverletzung indiziert sein.
Magnetic properties of FeCo alloy nanoparticles synthesized through instant chemical reduction
Authors: Karipoth Prakash , Thirumurugan Arun , Velaga Srihari , Greneche Jean-Marc , Justin Joseyphus R.
Published: September 2016

The chemical synthesis of shape and composition controlled Fe based binary alloys has been challenging due to the highly oxidizing nature of Fe. Here, we report the physical properties of flower-like Fe50Co50 nanoparticles prepared by a unique polyol process based on the addition of precursors at the elevated temperature. The magnetic properties are correlated through synchrotron radiation based X-ray diffraction and 57Fe Mössbauer spectrometry. Transmission electron microscopy analysis exposed the flower-like morphology of the FeCo particles. The FeCo nanoparticles showed a coercivity of 440 Oe, attributed to the shape anisotropy of the flower-like shape. Room temperature Mössbauer investigation revealed hyperfine fields of 34.9 and 36.7 T, suggesting two different Fe environments in the disordered state. Mössbauer analysis also showed the presence of superparamagnetic Fe-oxide with a relative fraction of 17%.
Gravity currents in a linearly stratified ambient fluid created by lock release and influx in semi-circular and rectangular channels
Authors: Longo S. , Ungarish M. , Di Federico V. , Chiapponi L. , Addona F.
Published: September 2016

We present an experimental investigation, supported by a theoretical model, of the motion of lock-release, constant inflow, and time varying inflow gravity currents (GCs) into a linearly stratified ambient fluid at large Reynolds number. The aim is the experimental validation of a simple model able to predict the slumping phase front speed and the asymptotic self-similar front speed for rectangular and circular cross section channels. The first investigated system is of Boussinesq type with the dense current (salt water dyed with aniline) released in a circular channel of 19 cm diameter and 400 cm long (605 cm in the inflow experiments), half-filled of linearly stratified ambient fluid (salt water with varying salt concentration). The second system has the same components but with a channel of rectangular cross section of 14 cm width, 11 cm ambient fluid depth, and 504 cm length. The density stratification of the ambient fluid was obtained with a computer controlled set of pumps and of mixing tanks. For the experiments with inflow, a multi-pipes drainage system was set at the opposite end with respect to the inflow section, computer controlled to avoid the selective withdrawal. The numerous experiments (28 for circular cross section, lock release; 26 for circular and 14 for rectangular cross section, constant inflow (fluid volume ∝tα, with α = 1); 6 for circular cross section, linearly increasing inflow (α = 2)), with several combination of the stratification parameter (0 < S < 1) confirm the theory within ≈30% (≈40% for a single series of experiments), which is considered a good result in view of the various underlying simplifications and approximations. The results on the front speed of the GCs are discussed in the presence of the internal waves, which have a celerity given by a theoretical and experimentally tested model for the rectangular but not for the circular cross section. The theoretical analysis of internal waves in circular cross sections has been extended and experimentally validated.
The “Fermi hole” and the correlation introduced by the symmetrization or the anti-symmetrization of the wave function
Authors: Giner Emmanuel , Tenti Lorenzo , Angeli Celestino , Malrieu Jean-Paul
Published: September 2016

The impact of the antisymmetrization is often addressed as a local property of the many-electron wave function, namely that the wave function should vanish when two electrons with parallel spins are in the same position in space. In this paper, we emphasize that this presentation is unduly restrictive: we illustrate the strong non-local character of the antisymmetrization principle, together with the fact that it is a matter of spin symmetry rather than spin parallelism. To this aim, we focus our attention on the simplest representation of various states of two-electron systems, both in atomic (helium atom) and molecular (H2 and the π system of the ethylene molecule) cases. We discuss the non-local property of the nodal structure of some two-electron wave functions, both using analytical derivations and graphical representations of cuttings of the nodal hypersurfaces. The attention is then focussed on the impact of the antisymmetrization on the maxima of the two-body density, and we show that it introduces strong correlation effects (radial and/or angular) with a non-local character. These correlation effects are analyzed in terms of inflation and depletion zones, which are easily identifiable, thanks to the nodes of the orbitals composing the wave function. Also, we show that the correlation effects induced by the antisymmetrization occur also for anti-parallel spins since all Ms components of a given spin state have the same N-body densities. Finally, we illustrate that these correlation effects occur also for the singlet states, but they have strictly opposite impacts: the inflation zones in the triplet become depletion zones in the singlet and vice versa.
I2 basal stacking fault as a degradation mechanism in reverse gate-biased AlGaN/GaN HEMTs
Authors: Lang A. C. , Hart J. L. , Wen J. G. , Miller D. J. , Meyer D. J. , Taheri M. L.
Published: September 2016

Here, we present the observation of a bias-induced, degradation-enhancing defect process in plasma-assisted molecular beam epitaxy grown reverse gate-biased AlGaN/GaN high electron mobility transistors (HEMTs), which is compatible with the current theoretical framework of HEMT degradation. Specifically, we utilize both conventional transmission electron microscopy and aberration-corrected transmission electron microscopy to analyze microstructural changes in not only high strained regions in degraded AlGaN/GaN HEMTs but also the extended gate-drain access region. We find a complex defect structure containing an I2 basal stacking fault and offer a potential mechanism for device degradation based on this defect structure. This work supports the reality of multiple failure mechanisms during device operation and identifies a defect potentially involved with device degradation.
Vapour-liquid coexistence of an active Lennard-Jones fluid
Authors: Prymidis Vasileios , Paliwal Siddharth , Dijkstra Marjolein , Filion Laura
Published: September 2016

We study a three-dimensional system of self-propelled Lennard-Jones particles using Brownian dynamics simulations. Using recent theoretical results for active matter, we calculate the pressure and report equations of state for the system. Additionally, we chart the vapour-liquid coexistence and show that the coexistence densities can be well described using simple power laws. Lastly, we demonstrate that our out-of-equilibrium system shows deviations from both the law of rectilinear diameters and the law of corresponding states.
Equivalent inertial time constant of doubly fed induction generator considering synthetic inertial control
Authors: Li Shichun , Deng Changhong , Shu Zhengyu , Huang Wentao , He Jun , You Zhou
Published: September 2016

The integration of large-scale doubly fed induction generators (DFIGs) into power system leads to the deterioration of the dynamic frequency characteristics in case of power shortage. One effective way to address this deterioration is through synthetic inertial control. However, a quantitative representation of the synthetic equivalent inertial time constant of DFIG (Heq) is greatly needed for research on the dynamic frequency characteristics of wind power-incorporating systems. This study introduces the traditional synthetic inertial control technique of DFIG, and reveals that the dynamic inertial response process is influenced by both the inertial controller and the speed controller. Expressions of Heq in the frequency and time domains were mathematically derived, and the accuracy of Heq was verified by comparing the calculated and simulated values. The 3-stage time varying characteristics of Heq are detailed, and the resulting mechanisms are analyzed.
New Raman measurements for H2O ice VII in the range of 300 cm−1 to 4000 cm−1 at pressures up to 120 GPa
Authors: Zha Chang-Sheng , Tse John S. , Bassett William A.
Published: September 2016

Raman spectroscopic measurements for H2O ice VII have been conducted to 120 GPa at 300 K in the spectroscopic range of 300–4000 cm−1. Both moissanite and diamond anvils were used for the experiments. This overcomes the problems of overlapping spectra between the diamond anvil and sample, which had prevented the observation of the stretching modes at pressures higher than ∼23 GPa in all previous measurements. The new results reveal many bands which have not been reported before. The pressure dependences of the Raman modes show anomalous changes at 13–15, ∼27, ∼44, ∼60, and 90 GPa, implying possible structural changes at these pressures. The new results demonstrate that the predicted symmetric hydrogen bond phase X transition does not occur below 120 GPa.
Enabling direct silicene integration in electronics: First principles study of silicene on NiSi2(111)
Authors: Cheng Jian-Yih , Chan Maria K. Y. , Lilley Carmen M.
Published: September 2016

Silicene on metal silicides poses promise for direct integration of silicene into electronic devices. The details of the metal silicide-silicene interface, however, may have significant effects on the electronic properties. In this work, we investigate the electronic properties of silicene on NiSi2(111) and hydrogenated NiSi2(111) (H:NiSi2) substrates, as well as hydrogenated silicene (H:silicene) on a NiSi2(111) substrate, from first principles. The preferred Si surface termination of NiSi2 was determined through surface energy calculations, and the band structure and density of states (DOS) were calculated for the two-dimensional silicene and H:silicene layers. Hydrogenating NiSi2 lowered the binding energy between silicene and the substrate, resulting in partial decoupling of the electronic properties. Relaxed silicene on H:NiSi2 showed a small band gap opening of 0.14 eV. Silicene on H:NiSi2 also had a calculated electron effective mass of 0.08m0 and a Fermi velocity of 0.39 × 106 m/s, which are similar to the values for freestanding silicene. H:silicene on NiSi2 retained its indirect band structure and DOS compared to freestanding H:silicene. The band gap of H:silicene on NiSi2 was 1.97 eV which is similar to the freestanding H:silicene band gap of 1.99 eV. This results showed that hydrogenation may be a viable method for decoupling a silicene layer from a NiSi2(111) substrate to tune its electronic properties.
Relaxation models for single helical reversed field pinch plasmas
Authors: Paccagnella Roberto
Published: September 2016

In this paper, a relaxation theory for plasmas where a single dominant mode is present [Bhattacharjee et al., Phys. Rev. Lett. 45, 347 (1980)], is revisited. The solutions of a related eigenvalue problem are numerically calculated and discussed. Although these solutions can reproduce well, the magnetic fields measured in experiments, there is no way within the theory to determine the dominant mode, whose pitch is a free parameter in the model. To find the preferred helical perturbation, a procedure is proposed that minimizes the “distance” of the relaxed state from a state which is constructed as a two region generalization of the Taylor's relaxation model [Taylor, Phys. Rev. Lett. 33, 1139 (1974); Rev. Mod. Phys. 58, 751 (1986)] and that allows current discontinuities. It is found that this comparison is able to predict the observed scaling with the aspect ratio and reversal parameter for the dominant mode in the Single Helical states. The aspect ratio scaling alone is discussed in a previous paper [Paccagnella, Nucl. Fusion 56, 046010 (2016)] in terms of the efficient response of a toroidal shell to specific modes (leaving a sign undetermined), showing that the ideal wall boundary condition, a key ingredient in relaxation theories, is particularly well matched for them. Therefore, the present paper altogether [Paccagnella, Nucl. Fusion 56, 046010 (2016)] can give a new and satisfactory explanation of some robust and reproducible experimental facts observed in the Single Helical Reversed Field Pinch plasmas and never explained before.
Collective water dynamics in the first solvation shell drive the NMR relaxation of aqueous quadrupolar cations
Authors: Carof Antoine , Salanne Mathieu , Charpentier Thibault , Rotenberg Benjamin
Published: September 2016

Using molecular simulations, we analyze the microscopic processes driving the Nuclear Magnetic Resonance (NMR) relaxation of quadrupolar cations in water. The fluctuations of the Electric Field Gradient (EFG) experienced by alkaline and magnesium cations, which determine the NMR relaxation time, are mainly due to the dynamics of water molecules in their solvation shell. The dynamics of the ion plays a less important role, with the exception of the short-time dynamics in the lighter Li+ case, for which rattling in the solvent cage results in oscillations of the EFG autocorrelation function (ACF). Several microscopic mechanisms that may a priori contribute to the decay of the EFG-ACF occur in fact over too long time scales: entrance/exit of individual water molecules into/from the solvation shell, rotation of a molecule around the ion, or reorientation of the molecule. In contrast, the fluctuations of the ion-water distance are clearly correlated to that of the EFG. Nevertheless, it is not sufficient to consider a single molecule due to the cancellations arising from the symmetry of the solvation shell. The decay of the EFG-ACF, hence NMR relaxation, is in fact governed by the collective symmetry-breaking fluctuations of water in the first solvation shell.
Structural deformation of 0.74Pb(Mg1/3Nb2/3)O3-0.26PbTiO3 single crystal in 1–3 composites due to interface stresses and poling procedure optimization
Authors: Wang Chunying , Sun Enwei , Liu Yingchun , Zhang Rui , Yang Bin , Cao Wenwu
Published: September 2016

Interface stresses strongly influence the functional property of 1–3 piezoelectric composites. Using the translucent nature of (1 − x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 single crystals, we have studied stress distributions and domain configuration changes during poling inside the crystal rods by polarizing light microscopy and piezoresponse force microscopy. It was found that the interface stresses due to interaction with polymeric filler led a deformed rhombohedral phase and caused incomplete poling near rod-edges. Compared with “hard” epoxy (Epotek301) filler, “soft” epoxy (Stycast) filler showed weaker impact on the crystals rods and less influence on domain configurations. We also show that high temperature poling (70 °C) can substantially improve the piezoelectric coefficient of composites filled with hard epoxy due to creeping above the glass transition Tg. Analytic stress distribution equations based on cylinder rods were modified to explain the physical principle and to predict the stress distribution for square rods case, which was verified by finite element simulation to be accurate within 5%.
A percolative approach to investigate electromigration failure in printed Ag structures
Authors: Zhao Zhao , Mamidanna Avinash , Lefky Christopher , Hildreth Owen , Alford T. L.
Published: September 2016

The ease of fabrication and wide application of printed microelectronics are driving advances in reactive inks. The long-term performance of structures printed using reactive ink is important for their application in microelectronics. In this study, silver lines are printed with low-temperature, self-reducing, silver-diamine based ink. The electromigration failure of the printed silver is first studied using Black's equation. However, due to the porous nature of the printed Ag line, Black's equation is not the best fit for predicting the lifetime, this is because Black's equation does not take into account morphology-induced current crowding. We find that the resistivity of the printed Ag lines can be described (as a function of void fraction) by percolation theory. In addition, we also demonstrate that the failure lifetimes of the printed Ag can be predicted quite well by a percolative model of failure.
Photovoltaic effect in YBa2Cu3O7−δ/Nb-doped SrTiO3 heterojunctions
Authors: Hao F. X. , Zhang C. , Liu X. , Yin Y. W. , Sun Y. Z. , Li X. G.
Published: September 2016

The photovoltaic properties of YBa2Cu3O7−δ/Nb-doped SrTiO3 (SNTO) heterostructures were investigated systematically under laser irradiation of different wavelengths from 365 nm to 640 nm. A clear photovoltaic effect was observed, and the photovoltage Voc ranged from 0.1 V to 0.9 V depending on the wavelength. The Voc appeared under laser illumination with a photon energy of 2.4 eV, far below the band gap (3.2 eV) of Nb-doped SrTiO3. The temperature dependencies of the Voc and short-current density showed kinks near the structural phase transition of the Nb-doped SrTiO3. Our findings are helpful for understanding the photovoltaic effect in transition-metal oxide based heterojunctions and designing such photovoltaic devices.
Band gap reduction in InNxSb1-x alloys: Optical absorption, k · P modeling, and density functional theory
Authors: Linhart W. M. , Rajpalke M. K. , Buckeridge J. , Murgatroyd P. A. E. , Bomphrey J. J. , Alaria J. , Catlow C. R. A. , Scanlon D. O. , Ashwin M. J. , Veal T. D.
Published: September 2016

Using infrared absorption, the room temperature band gap of InSb is found to reduce from 174 (7.1 μm) to 85 meV (14.6 μm) upon incorporation of up to 1.13% N, a reduction of ∼79 meV/%N. The experimentally observed band gap reduction in molecular-beam epitaxial InNSb thin films is reproduced by a five band k · P band anticrossing model incorporating a nitrogen level, EN, 0.75 eV above the valence band maximum of the host InSb and an interaction coupling matrix element between the host conduction band and the N level of β = 1.80 eV. This observation is consistent with the presented results from hybrid density functional theory.
Photosensitivity of InZnO thin-film transistors using a solution process
Authors: Choi Jongwon , Park Junghak , Lim Keon-Hee , Cho Nam-kwang , Lee Jinwon , Jeon Sanghun , Kim Youn Sang
Published: September 2016

Oxide semiconductor devices play a role in both switches and photo-sensors in interactive displays. During the fabrication of oxide semiconductor devices, the sol-gel solution process that is used to form an oxide semiconductor has various merits, including its simplicity and low cost as well as its good composition controllability. Here, we present the photosensitivity characteristics of an oxide photo thin-film transistor (TFT) created using the InZnO (IZO) sol-gel process. Upon exposure to light, photocurrent (Iphoto) in the negative gate bias regime is significantly increased with a negligible threshold voltage shift. The photosensitivity is modulated by geometrical factors and by the IZO material composition. We observed a significant effect of the channel thickness and IZO composition on the photosensitivity, which was attributed to the screening effect of optically ionized oxygen vacancies (Vo++). In particular, the optimized bi-layered oxide photo-TFT presents a good Iphoto/Idark photosensitivity value of 3 × 104 and a subthreshold slope of 0.96 V/decade. In addition, the persistent photoconductivity of the oxide photo-TFT was removed by applying positive gate voltage, resulting in good high-speed operation. These results taken together demonstrate that the IZO photo-TFT produced by the sol-gel process can be workable when applied to interactive displays.
A micromechanical switchable hot spot for SERS applications
Authors: Naumenko Denys , Toffoli Valeria , Greco Silvio , Dal Zilio Simone , Bek Alpan , Lazzarino Marco
Published: September 2016

Hot spots are defined as nanostructures of noble metal able to locally enhance the electromagnetic field of several orders of magnitude and to confine this effect to a region for several orders of magnitude smaller than the light wavelength. Hot spots are particularly important for the surface enhanced Raman spectroscopy applications, in which the field enhancement is used to amplify the usually weak Raman scattering signal. The hot spots are mostly generated between two or more plasmonic nanostructures separated by nanometric gaps. Several strategies are used to design and realize the hot spots, both in solution, using the noble metal nanoparticles, and on surfaces, using nanolithography and evaporation. In this paper, we demonstrated the fabrication of a nanomechanical plasmonic device for Raman spectroscopy, in which the hot spots are switched on when biased at the resonant frequency and switched off when the actuation signal is removed.
Nanocrystalline diamond micro-anvil grown on single crystal diamond as a generator of ultra-high pressures
Authors: Samudrala Gopi K. , Moore Samuel L. , Velisavljevic Nenad , Tsoi Georgiy M. , Baker Paul A. , Vohra Yogesh K.
Published: September 2016

By combining mask-less lithography and chemical vapor deposition (CVD) techniques, a novel two-stage diamond anvil has been fabricated. A nanocrystalline diamond (NCD) micro-anvil 30 μm in diameter was grown at the center of a [100]-oriented, diamond anvil by utilizing microwave plasma CVD method. The NCD micro-anvil has a diamond grain size of 115 nm and micro-focused Raman and X-ray Photoelectron spectroscopy analysis indicate sp3-bonded diamond content of 72%. These CVD grown NCD micro-anvils were tested in an opposed anvil configuration and the transition metals osmium and tungsten were compressed to high pressures of 264 GPa in a diamond anvil cell.
BN/BNSiO2 sputtering yield shape profiles under stationary plasma thruster operating conditions
Authors: Ranjan M. , Sharma A. , Vaid A. , Bhatt T. , Nandalan V. , James M. G. , Revathi H. , Mukherjee S.
Published: September 2016

Quartz Crystal Microbalance (QCM) is used to measure the volumetric and total sputtering yield of Boron Nitride (BN) and Boron Nitride Silicon Dioxide (BNSiO2) bombarded by Xenon ions in the energy range of 100 eV to 550 eV. Sputtering yield shape profiles are reported at various angles of incidence 0-85° with surface normal and compared with modified Zhang model. The yield shape profile is found to be symmetric at normal incidence and asymmetric at oblique incidence. Both the materials show a sudden jump in the sputtering yield above 500 eV and at an angle of incidence in the range of 45-65°. Erosion of BN at as low as 74 eV ion energy is predicted using generalized Bohdansky model. BNSiO2 show a marginally higher sputtering yield compare to BN.
Structural and photoluminescence properties of tin oxide and tin oxide: C core–shell and alloy nanoparticles synthesised using gas phase technique
Authors: Bhatnagar Mehar , Kaushik Vishakha , Kaushal Akshey , Singh Mandeep , Mehta Bodh Raj
Published: September 2016

In the present study, we report a controlled growth of tin oxide and tin oxide: carbon nanoparticles by an integrated method comprising of the gas phase agglomeration, electrical mobility based size selection, and in–flight sintering steps. The effect of in-flight sintering temperature and variation in growth environment (N2, H2 and O2) during nanoparticle formation, morphology and composition has been investigated by carrying out High Resolution Transmission Electron microscopy and X-Ray diffraction studies. The results highlight the novelty of the present technique to grow alloy and core-shell nanoparticles in which the stoichiometery (x) of SnOx and the mode of incorporation of carbon into the tin oxide lattice (alloy or core-shell structure), along with well-defined size can be controlled independently. Detailed Photoluminescence (PL) studies of well sintered monocrystalline SnO, SnOx and SnO2 nanoparticles along with SnOx:C and SnO2:C alloy and C@SnO core-shell nanoparticle has been carried out. The shift in the position and nature of PL peaks due to band edge, Sn interstitials and oxygen vacancy defect level energy states has been understood as a function of stoichiometery and nanoparticle structure (alloy and core-shell). These results suggest the possibility of tailoring the position of these levels by controlling the size, composition and alloying which is potentially important for gas sensing, photoconductivity and photo-electrochemical applications.
Pregnancy, the placenta and Zika virus (ZIKV) infection
Authors: Rawlinson William
Published: September 2016

Zika virus (ZIKV) infections have been recognised in Africa and Asia since 1940. The virus is in the family Flaviviridae and genus Flavivirus, along with Dengue, Japanese encephalitis virus, Tick borne encephalitis, West Nile virus, and Yellow fever virus. These viruses share biological characteristics of an envelope, icosahedral nucleocapsid, and a non-segmented, positive sense, single-strand RNA genome of ~10kb encoding three structural proteins (capsid C pre-membrane/membrane PrM/M, envelope E), and seven non-structural proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B and NS5). ZIKV has three known genotypes; the West African (Nigerian cluster), East African (MR766 prototype cluster), and Asian strains. Virus sequencing from the most recent South American outbreak suggests this virus is related to the 2013 French Polynesian isolates of Asian lineage.
Bursts of activity in collective cell migration
Authors: Chepizhko Oleksandr , Giampietro Costanza , Mastrapasqua Eleonora , Nourazar Mehdi , Ascagni Miriam , Sugni Michela , Fascio Umberto , Leggio Livio , Malinverno Chiara , Scita Giorgio , Santucci Stéphane , Alava Mikko J. , Zapperi Stefano , La Porta Caterina A. M.
Published: September 2016

Significance

During wound healing and in cancer invasion, cells migrate collectively driven by active internal forces and invade the available space. Here we show that this motion occurs by intermittent bursts of activity described by universal scaling laws similar to the ones observed in other driven systems where a front propagates in response to an external force, such as in fracture and fluid imbibition. Our results demonstrate that living systems display universal nonequilibrium critical fluctuations, induced by cell mutual interactions, that are usually associated with externally driven inanimate media.
Two subdivisions of macaque LIP process visual-oculomotor information differently
Authors: Chen Mo , Li Bing , Guang Jing , Wei Linyu , Wu Si , Liu Yu , Zhang Mingsha
Published: September 2016

Significance

The lateral intraparietal cortex (LIP) in primates links circuits for vision and saccadic eye movements. Neurons in LIP discharge during visually evoked saccades, but it is not certain whether LIP activity is primarily related to vision or to eye movement. From neuroanatomical evidence, we propose that LIP has two distinct subdivisions, dorsal and ventral LIP, with the dorsal division more concerned with visual processing and the ventral division more concerned with saccades. We provide evidence from both electrophysiological recordings and local inactivation to support our hypothesis. We therefore demonstrate that the two subdivisions of LIP play distinct roles in linking vision with visually guided action.
Atomic lattice disorder in charge-density-wave phases of exfoliated dichalcogenides (1T-TaS
2
)
Authors: Hovden Robert , Tsen Adam W. , Liu Pengzi , Savitzky Benjamin H. , El Baggari Ismail , Liu Yu , Lu Wenjian , Sun Yuping , Kim Philip , Pasupathy Abhay N. , Kourkoutis Lena F.
Published: September 2016

Significance

Low-dimensional materials, such as 1T-TaS
2
, permit unique phases that arise through electronic and structural reshaping known, respectively, as charge-density waves and periodic lattice distortions (PLDs). Determining the atomic structure of PLDs is critical toward understanding the origin of these charge-ordered phases and their effect on electronic properties. Here we reveal the microscopic nature of PLDs at cryogenic and room temperature in thin flakes of 1T-TaS
2
using atomic resolution scanning transmission electron microscopy. Real-space characterization of the local PLD structure across the phase diagram will enable harnessing of emergent properties of thin transition-metal dichalcogenides.
A ring-shaped conduit connects the mother cell and forespore during sporulation in
Bacillus subtilis
Authors: Rodrigues Christopher D. A. , Henry Xavier , Neumann Emmanuelle , Kurauskas Vilius , Bellard Laure , Fichou Yann , Schanda Paul , Schoehn Guy , Rudner David Z. , Morlot Cecile
Published: September 2016

Significance

Specialized secretion systems transport proteins across the double-membrane cell envelope of Gram-negative bacteria. Gram-positive bacteria possess a single membrane and lack many of these secretion systems. During endospore formation in Gram-positive bacteria such as
Bacillus subtilis
, a double-membrane envelope surrounds the developing spore. A transenvelope complex with similarities to Gram-negative specialized secretion systems spans the two membranes separating mother cell and endospore. This complex is essential for development and has been hypothesized to serve as a channel for molecular transport between the two cells. Here we show that it contains an oligomeric ring with architecture and dimensions similar to those found in type III secretion systems, providing direct evidence for a conduit connecting mother cell and developing spore.
A penicillin-binding protein inhibits selection of colistin-resistant, lipooligosaccharide-deficient
Acinetobacter baumannii
Authors: Boll Joseph M. , Crofts Alexander A. , Peters Katharina , Cattoir Vincent , Vollmer Waldemar , Davies Bryan W. , Trent M. Stephen
Published: September 2016

Significance

Antimicrobial drug resistance is a major threat to public health. Gram-negative bacteria are exceptionally resistant to antibiotics because of their outer-membrane barrier. Glycolipids called lipopolysaccharide (LPS) or lipooligosaccharide (LOS) fortify the outer membrane from many antimicrobials and biocides and were thought to be essential for Gram-negative bacterial survival. The last-resort treatment for multidrug-resistant Gram-negative infections is colistin, which targets the lipid A domain of LPS/LOS to disrupt the membrane, but the emerging pathogen
Acinetobacter baumannii
can develop colistin resistance by inactivating lipid A biosynthesis. This analysis advances our understanding of lipid A/LOS essentiality in
A. baumannii
and identifies antimicrobial targets.
C-terminal domain of the RNA chaperone Hfq drives sRNA competition and release of target RNA
Authors: Santiago-Frangos Andrew , Kavita Kumari , Schu Daniel J. , Gottesman Susan , Woodson Sarah A.
Published: September 2016

Significance

The RNA chaperone Hfq binds hundreds of small noncoding RNAs (sRNAs) and facilitates their interactions with mRNAs, regulating bacterial stress responses and virulence. Hfq is limiting in the cell and must release RNAs after they base pair. Most bacterial Hfqs contain an intrinsically disordered C-terminal domain (CTD), with unknown function. Time-resolved assays now show that CTDs are needed to displace base-paired RNA, recycling Hfq. The CTDs also enable kinetic competition between different sRNAs in
Escherichia coli
, allowing some sRNAs to bind Hfq and accumulate, whereas other sRNAs are degraded. We propose that the CTDs sweep sRNAs from the surface of Hfq. This displacement allows Hfq to search among potential RNA partners and establishes a hierarchy of sRNA regulation.
Substrate temperature and thickness dependence of properties of boron and gallium co-doped ZnO films
Authors: Yang J. , Huang J. , Lu Y. X. , Ji H. H. , Zhang L. , Tang K. , Cao M. , Hu Y. , Wang L. J.
Published: September 2016

Transparent conducting oxide films of boron and gallium co-doped ZnO (BGZO) were prepared on glass substrates by radio frequency magnetron sputtering at room temperature and 200°C, respectively. The dependence of structural, electrical and optical properties on the thickness and substrate temperature were investigated. All films demonstrated c-axis preferred orientation and showed highly transparent in the visible wavelength region. With the increase thickness and substrate temperature, the grain size of BGZO films increased and the full width at half maximum decreased, the carrier mobility increased and resistivity decreased, which indicated that the crystallinity and conductivity of films were improved. The research also found that the optical band gap ( Eg) of BGZO thin films decreased with increased substrate temperature and thickness.
Women’s protests: gender, imprisonment and resistance in South Africa (Pollsmoor Prison, 1970s–90s)
Authors: Filippi Natacha
Published: September 2016

This article presents a historical investigation of the modalities of protest adopted by women prisoners in South Africa from the 1970s to 1994. It explores how the introduction of a gender perspective provides new insights on the strategies of adaptation and resistance within closed institutions and the way these were intertwined with broader social dynamics. The article focuses on the criminalisation processes to which black women were subjected under apartheid, on how the beginning of the democratic transition coincided with the emergence of new actors inside prisons and on the participation of women in the 1994 large-scale prison revolts.
Perturbation of neddylation-dependent NF-κB responses in the intestinal epithelium drives apoptosis and inhibits resolution of mucosal inflammation
Authors: Ehrentraut Stefan F. , Curtis Valerie F. , Wang Ruth X. , Saeedi Bejan J. , Ehrentraut Heidi , Onyiah Joseph C. , Kelly Caleb J. , Campbell Eric L. , Glover Louise E. , Kominsky Douglas J. , Colgan Sean P.
Published: September 2016

Recent work has revealed a central role for neddylation (the conjugation of a Nedd8 moiety to Cullin proteins) in the fine-tuning of the NF-κB response (via Cullin-1). In the present study, we investigated the contribution of Cullin-1 neddylation and NF-κB signaling to mucosal inflammatory responses in vitro and in vivo. Initial in vitro studies using cultured intestinal epithelial cells revealed that the neddylation inhibitor MLN4924 prominently induces the deneddylation of Cullin-1. Parallel Western blot, luciferase reporter, and gene target assays identified MLN4924 as a potent inhibitor of intestinal epithelial NF-κB. Subsequent studies revealed that MLN4924 potently induces epithelial apoptosis but only in the presence of additional inflammatory stimuli. In vivo administration of MLN4924 (3 mg/kg per day) in a TNBS-induced colitis model significantly accentuated disease severity. Indeed, MLN4924 resulted in worsened clinical scores and increased mortality early in the inflammatory response. Histologic analysis of the colon revealed that neddylation inhibition results in increased tissue damage and significantly increased mucosal apoptosis as determined by TUNEL and cleaved caspase-3 staining, which was particularly prominent within the epithelium. Extensions of these studies revealed that ongoing inflammation is associated with significant loss of deneddylase-1 (SENP8) expression. These studies reveal that intact Cullin-1 neddylation is central to resolution of acute inflammation.
Blood: A Very Short Introduction
Authors: Cooper Chris
Published: September 2016

Blood is vital to most animals. In mammals it transports oxygen and food, carries away waste, and contains the white cells that attack invading microbes. Playing a central role in life, blood has profound cultural and historical significance and plays an important role in religious ritual. Blood was one of the four humours in early Western medicine and is still a major diagnostic tool in the doctor’s armoury. Blood: A Very Short Introduction analyses the components of blood, explains blood groups, and looks at transfusions, blood tests, and blood-borne diseases. It considers the future, including the possibility of making artificial blood, and producing blood from stem cells in the laboratory.
Comparing co-evolution methods and their application to template-free protein structure prediction
Authors: de Oliveira Saulo Henrique Pires , Shi Jiye , Deane Charlotte M
Published: September 2016

Motivation

Co-evolution methods have been used as contact predictors to identify pairs of residues that share spatial proximity. Such contact predictors have been compared in terms of the precision of their predictions, but there is no study that compares their usefulness to model generation.

Results

We compared eight different co-evolution methods for a set of ∼3500 proteins and found that metaPSICOV stage 2 produces, on average, the most precise predictions. Precision of all the methods is dependent on SCOP class, with most methods predicting contacts in all α and membrane proteins poorly. The contact predictions were then used to assist in de novo model generation. We found that it was not the method with the highest average precision, but rather metaPSICOV stage 1 predictions that consistently led to the best models being produced. Our modelling results show a correlation between the proportion of predicted long range contacts that are satisfied on a model and its quality. We used this proportion to effectively classify models as correct/incorrect; discarding decoys classified as incorrect led to an enrichment in the proportion of good decoys in our final ensemble by a factor of seven. For 17 out of the 18 cases where correct answers were generated, the best models were not discarded by this approach. We were also able to identify eight cases where no correct decoy had been generated.

Availability and Implementation

Data is available for download from: http://opig.stats.ox.ac.uk/resources.

Supplementary information

Supplementary data are available at Bioinformatics online.
Granular clustering of de novo protein models
Authors: Guzenko Dmytro , Strelkov Sergei V
Published: September 2016

Motivation

Modern algorithms for de novo prediction of protein structures typically output multiple full-length models (decoys) rather than a single solution. Subsequent clustering of such decoys is used both to gauge the success of the modelling and to decide on the most native-like conformation. At the same time, partial protein models are sufficient for some applications such as crystallographic phasing by molecular replacement (MR) in particular, provided these models represent a certain part of the target structure with reasonable accuracy.

Results

Here we propose a novel clustering algorithm that natively operates in the space of partial models through an approach known as granular clustering (GC). The algorithm is based on growing local similarities found in a pool of initial decoys. We demonstrate that the resulting clusters of partial models provide a substantially more accurate structural detail on the target protein than those obtained upon a global alignment of decoys. As the result, the partial models output by our GC algorithm are also much more effective towards the MR procedure, compared to the models produced by existing software.

Availability and Implementation

The source code is freely available at https://github.com/biocryst/gc

Supplementary information

Supplementary data are available at Bioinformatics online.
A simple technique for suppressor detection inEscherichia coli
Authors: Vinué Laura , Hooper David C.
Published: September 2016

To study the viability of agyrA S83 stop mutation found in anEscherichia coli J53 ciprofloxacin-resistant strain (J53 CipR27), a pBR322 derivative was constructed with a TAG mutation in thebla gene knocking out ampicillin resistance. Ampicillin resistance was restored, suggesting that the strain contains tRNA suppressor activity able to suppress the UAG codongyrA and allow viability. The method was applied to 22 unique clinicalE. coli isolates, and all were found to have low-level suppressor activity.
Using a domestic and sexual violence prevention advocate to implement a dating violence prevention program with athletes
Authors: Jaime M. C. D. , Stocking M. , Freire K. , Perkinson L. , Ciaravino S. , Miller E.
Published: September 2016

‘Coaching Boys into Men’ is an evidence-based dating violence prevention program for coaches to implement with male athletes. A common adaptation of this program is delivery by domestic violence and sexual violence prevention advocates instead of coaches. We explored how this implementer adaptation may influence athlete uptake of program messages and outcomes. Randomly, one school received the program delivered by an advocate while another school received the program delivered by coaches. Athletes completed baseline and follow-up surveys (n = 148), and a subset who received the advocate-led program participated in focus groups (four groups; n = 26). We compared changes in athlete attitudes and behaviors and conducted thematic analyses with qualitative data. We found no significant differences between athletes who received the program from the advocate versus their coaches. Athletes highlighted the advocate’s delivery and role as a non-judgmental adult ally as qualities that influenced their uptake of program messages. The acceptability of the advocate-led program may be related to the implementer type along with specific implementer characteristics and delivery methods. Using advocates together with coaches as implementers could increase the reach of this program. Further study of best practices for Coaching Boys into Men adaptation is needed to guide program dissemination and sustainability.
Moving from ecosystem-based policy objectives to operational implementation of ecosystem-based management measures
Authors: Cormier Roland , Kelble Christopher R. , Anderson M. Robin , Allen J. Icarus , Grehan Anthony , Gregersen Ólavur
Published: September 2016

The aim of ecosystem-based management (EBM) is to maintain an ecosystem in a healthy, productive and resilient condition through the implementation of policies and management measures. Although cross-sectoral planning may be led by a planning competent authority, it is up to the sector competent authority to implement the necessary management measures within their operations to achieve EBM goals and objectives. We suggest that scientific impediments to EBM are no longer significant to implement EBM operationally. Instead, we consider that approaching EBM within current policy cycle approaches would provide the necessary policymaking process step to operationalize EBM. In addition to enabling and facilitating collaboration, exchange, understanding as promoted by EBM, policymaking processes also require that policy is to be implemented through programs, measures, procedures and controls that have expected outcomes to “carry into effect” the policy objective. We are of the view that moving EBM from planning and objective setting to operational implementation is a management problem solving issues instead of a scientific one.
How social network role, geographical context and territorial mobility mediate the adoption of transgressive styles in the jazz field
Authors: Kirschbaum Charles , Ribeiro Priscila Fernandes
Published: September 2016

We explore the relationship between network role, territorial location and the adoption of transgressive styles on jazz music between 1950 and 1969. Our study contributes to the literature on the role of networks in the adoption of innovations, employing the following analytic strategies: (1) we use regular equivalence to identify clusters hierarchically related to each other; (2) classify these clusters into role types; (3) we determine the extent to which territory moderates the relationship between role and the adoption of innovation and (4) we show that territorial location and mobility emerge as an alternative mechanism to network role.
Building Collaboration: Examining the Relationship between Collaborative Processes and Activities
Authors: Sedgwick Donna
Published: September 2016

This study investigates if the collaborative process differs among a group of public programs involved in varying levels of interorganizational activities. Thomson and Perry (2006) suggest five process dimensions underlie collaboration: governance, administration, norms of trust, mutuality, and organizational autonomy. While these dimensions are clearly unique, it is unclear if any of these dimensions are necessary or sufficient for varying degrees of interorganizational involvement. Inventorying the interorganizational activities of pairs of government-funded preschools as ranging along a continuum of no relationship, cooperation, coordination, and collaboration, I conduct a qualitative comparative analysis (QCA) to assess the relationship between collaborative processes and activities. The findings suggest that the collaborative processes dimensions differ depending on the level of involvement. The QCA results also reveal substitutable combinations of process dimensions that underlie respective degrees of interorganizational involvement, offering insight to public managers about different skill sets they can focus on when managing interorganizational activities.