bluuebunny/crossref_metadata_2025 huggingface dataset:
Coordination of o-benzosemiquinonate, o-iminobenzosemiquinonate and aldimine anion radicals to oxidovanadium(iv)
Authors: Shit Madhusudan , Bera Sachinath , Maity Suvendu , Weyhermüller Thomas , Ghosh Prasanta
Published: April 2017

o-Benzosemiquinonate,o-iminobenzosemiquinonate and hitherto unknown aldimine anion radical complexes of oxidovanadium(iv) are reported.
High phosphate induces a pro-inflammatory response by vascular smooth muscle cells and modulation by vitamin D derivatives
Authors: Martínez-Moreno Julio M. , Herencia Carmen , de Oca Addy Montes , Díaz-Tocados Juan M. , Vergara Noemi , Gómez-Luna  M. José , López-Argüello Silvia D. , Camargo Antonio , Peralbo-Santaella Esther , Rodríguez-Ortiz Maria E. , Canalejo Antonio , Rodríguez Mariano , Muñoz-Castañeda Juan R. , Almadén Yolanda
Published: April 2017

In chronic kidney disease patients, high phosphate (HP) levels are associated with cardiovascular disease, the major cause of morbidity and mortality. Since serum phosphate has been independently correlated with inflammation, the present study aimed to investigate an independent direct effect of HP as a pro-inflammatory factor in VSMCs. A possible modulatory effect of vitamin D (VitD) was also investigated. The study was performed in an in vitro model of human aortic smooth muscle cells (HASMCs). Incubation of cells in an HP (3.3 mM) medium caused an increased expression of the pro-inflammatory mediators intercellular adhesion molecule 1 (ICAM-1), interleukins (ILs) IL-1β, IL-6, IL-8 and tumour necrosis factor α (TNF-α) (not corroborated at the protein levels for ICAM-1), as well as an increase in reactive oxygen/nitrogen species (ROS/RNS) production. This was accompanied by the activation of nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) signalling as demonstrated by the increase in the nuclear translocation of nuclear factor κ-light-chain-enhancer of activated B cells protein 65 (p65-NF-κΒ) assessed by Western blotting and confocal microscopy. Since all these events were attenuated by an antioxidant pre-incubation with the radical scavenger Mn(III)tetrakis (4-benzoic acid) porphyrin (MnTBAP), it is suggested that the inflammatory response is upstream mediated by the ROS/RNS-induced activation of NF-κΒ. Addition of paricalcitol (PC) 3·10−8 M to cells in HP prevented the phosphate induced ROS/RNS increase, the activation of NF-κΒ and the cytokine up-regulation. A bimodal effect was observed, however, for different calcitriol (CTR) concentrations, 10−10 and 10−12 M attenuated but 10−8 M stimulated this phosphate induced pro-oxidative and pro-inflammatory response. Therefore, these findings provide novel mechanisms whereby HP may directly favour vascular dysfunctions and new insights into the protective effects exerted by VitD derivatives.
Loop‐type ground radiation antenna for a discontinuous square ring‐shaped ground plane
Authors: Zahid Zeeshan , Kim Hyeongdong
Published: April 2017

A loop‐type ground radiation antenna is proposed for a discontinuous square ring‐shaped ground plane. The antenna shows strong coupling with the ground mode if it is located at the maximum current density location. The location of the antenna has been evaluated using characteristic mode analysis of the currents on the ground plane. The size of the loop‐type ground radiation antenna is 10 × 4.5 mm and it is fabricated on a square ring‐shaped ground plane of size 50 × 50 mm having a gap of 2 mm. The design is intended for mobile device applications operating at 2.45 GHz.
Analytical technique for synchronous generator loss‐of‐excitation protection
Authors: Noroozi Naser , Yaghobi Hamid , Alinejad‐Beromi Yoosef
Published: April 2017

This study introduces a new analytical approach for the detection of loss of excitation (LOE) in a synchronous generator that uses only one local variable. The proposed method applies the mathematical analysis based on the generator armature current variation. In this method, after the generator loses its excitation, the second order derivative of generator armature current becomes and remains positive until a loss of synchronism event occurs. Simulations are performed for different levels of generator conditions and loads, and the results confirm the mathematical analysis. To demonstrate the suitability of the proposed method, comparisons are made with other protection methods. Studies show that the proposed strategy offers a better security and faster detection of LOE compared with the previous methods.
Variational mode decomposition‐based power system disturbance assessment to enhance WA situational awareness and post‐mortem analysis
Authors: Jena Manas Kumar , Samantaray Subhransu Ranjan , Panigrahi Bijaya Ketan
Published: April 2017

This study presents a variational mode decomposition (VMD)‐based approach to analyse wide‐area (WA) measurements based signals. The commonly used empirical mode decomposition (EMD) has limitations such as sensitivity to noise and sampling rate. However, VMD is an entirely non‐recursive algorithm, where the modes are extracted concurrently. These modes help in extracting dynamic patterns of different power system disturbances. The performance of the proposed scheme is extensively validated on the IEEE‐39 bus New England test system. The modes generated and the frequency deviation contours of the disturbances including generation loss, fault and line outage are assessed using VMD and the results provide improved performance in terms of decomposition quality compared with the existing EMD technique. Furthermore, a data‐mining model known as decision tree is used to classify different power system disturbances based on intrinsic mode functions generated through VMD. The suggested method shows improved decomposition quality and classification accuracy. Thus, the proposed scheme is a potential candidate for improving WA situational awareness along with a post‐mortem analysis of real events occurring in a power system.
Performance analysis of DSTATCOM employing various control algorithms
Authors: Mangaraj Mrutyunjaya , Panda Anup Kumar
Published: April 2017

This research work introduces a new hybrid technique called quasi‐Newton back‐propagation based i cosϕ control algorithm. Its structure is constructed on the concept of biological features like input neuron, target neuron, weight correction and more attractive due to its parallel computing, learning capability behaviour. Systematic step‐by‐step procedures are represented by mathematical equations in the MATLAB/Simulink platform. The fundamental weighted values of active and reactive power components of load currents are extracted using the proposed control technique to generate the reference source currents. Further, the reference source currents are used to generate switching pulses for voltage source converter (VSC) of the distributed static compensator (DSTATCOM). It is capable enough to perform several functions such as harmonic mitigation, power factor correction, load balancing and voltage regulation which further reduce the DC link voltage across the self‐supported capacitor of the VSC. Simulation and experimental validation demonstrates better performance of the suggested algorithm for operation of the DSTATCOM at different loading conditions.
Energy management in DC microgrid with energy storage and model predictive controlled AC–DC converter
Authors: Rana Md Juel , Abido Mohammad Ali
Published: April 2017

Renewable energy‐based direct current microgrids are becoming popular due to their higher energy efficiency than AC microgrids. Energy storage system (ESS) helps to stabilise the system against the instability caused by stochastic nature of the renewable sources as well as demand variation within a microgrid. This work proposes effective energy management and control techniques for a photovoltaic‐based DC microgrid. In order to regulate power exchange with the main grid, model predictive controller (MPC) is proposed to control bidirectional voltage source converter. The performance of MPC is compared with classical PI controller. Frequency approach control of hybrid ESS comprising of battery and supercapacitor is used to suppress both low‐ and high‐frequency power variation in the microgrid by exchanging power with DC bus. To confirm the efficacy of proposed control strategy, real‐time simulations of the system are carried out considering both grid‐connected and islanded modes of the microgrid operation. The results show the effectiveness of the proposed control strategy for energy management in the microgrid. Further, real‐time controller hardware‐in‐the‐loop experiment validates the simulation results.
Polynomial regression models to explain the relationship between network and service key performance indicators
Authors: Costantini Luca , Mammi Elena , Teodori Marco , Attanasio Vincenzo
Published: April 2017

In the future networks, the level of quality of services (QoS) will be improved, new services will be introduced and the end users will enjoy everywhere and any time old and new services via fixed and mobile devices. Then the quality will be a key aspect for the next generation network. In this context, the relationship between the network performances and the QoS become an important issue. In this study, the quality of network and QoS in future system are studied, an agent to measure the key performance indicators values has been created and a polynomial regression models to explain the relationship between network and service KPIs is employed.
Effect of measurement temperature on power transformer insulation diagnosis using frequency‐domain spectroscopy
Authors: Dutta Saurabh , Baral Arijit , Pradhan Arpan Kumar , Chakravorti Sivaji
Published: April 2017

Frequency‐domain spectroscopy (FDS) is a widely accepted method for the estimation of moisture content in oil–paper insulation of power transformer. Researchers have shown that measurement temperature is an important factor that not only shifts the tan δ curve both horizontally and vertically with respect to frequency axis but also affects the value of paper‐moisture content of transformer insulation. This implies FDS data measured at different temperatures yields different results even if the insulation under consideration remains more or less unaffected. Availability and construction of master curve for in‐service real‐life units might not always be available. This study proposes a method that is capable of predicting the profile of tan δ curve at different measurement temperatures. Existing expressions available for predicting paper‐moisture does not consider the effect of change in measurement temperature. This study also proposes modification of existing expression to predict the moisture content of insulation paper at any measurement temperature. In addition, this study outlines a method to evaluate the value of activation energy (Ea) from the insulation response. The discussed technique is first tested successfully on data recorded from a laboratory sample. Thereafter, the method is applied on data collected from a real‐life power transformer.
Measuring surface magnetic fields of red supergiant stars
Authors: Tessore B. , Lèbre A. , Morin J. , Mathias P. , Josselin E. , Aurière M.
Published: April 2017

Context.Red supergiant (RSG) stars are very massive cool evolved stars. Recently, a weak magnetic field was measured at the surface ofαOri and this is so far the only M-type supergiant for which a direct detection of a surface magnetic field has been reported.

Aims.By extending the search for surface magnetic field in a sample of late-type supergiants, we want to determine whether the surface magnetic field detected onαOri is a common feature among the M-type supergiants.

Methods.With the spectropolarimeter Narval at TélescopeBernard-Lyotwe undertook a search for surface magnetic fields in a sample of cool supergiant stars, and we analysed circular polarisation spectra using the least-squares deconvolution technique.

Results.We detect weak Zeeman signatures of stellar origin in the targets CE Tau,α1Her andμCep. For the latter star, we also show that cross-talk from the strong linear polarisation signals detected on this star must be taken into account. For CE Tau andμCep, the longitudinal component of the detected surface fields is at the Gauss-level, such as inαOri. We measured a longitudinal field almost an order of magnitude stronger forα1Her. We also report variability of the longitudinal magnetic field of CE Tau andα1Her, with changes in good agreement with the typical atmospheric dynamics time-scales. We also report a non-detection of magnetic field at the surface of the yellow supergiant starρCas.

Conclusions.The two RSG stars of our sample, CE Tau andμCep, display magnetic fields very similar to that ofαOri. The non-detection of a magnetic field on the post-RSG starρCas suggests that the magnetic field disappears, or at least becomes undetectable with present methods, at later evolutionary stages. Our analysis ofα1Her supports the proposed reclassification of the star as an M-type asymptotic giant branch star.
Synthesis of Allylbenzene Derivatives through sp3 C–H Bond Functionalization of Toluene Derivatives
Authors: Abbasi Alireza , Ghazanfarpour-Darjani Majid , Shahsavari Fatemeh , Ghafelebashi Seyed , Daftari-Besheli Majid
Published: April 2017

An sp3 C–H bond-transformation reaction of toluene substrates to afford the corresponding allylbenzene derivatives is described. Optimum conditions were identified as involving the use of tetrabutylammonium iodide and tert-butyl hydroperoxide at 80 °C.
Prenatal Diagnosis of Galen Vein Aneurysm Using Ultrasonography and Magnetic Resonance Imaging and Perinatal and Long-Term Neurological Outcomes: A Case Series
Authors: Pires Pedro , Martins Larisse de Brito Aurélio , Pires Norma Maria Tenório Brito , Werner Heron , Ferreira Adilson Cunha , Araujo Júnior Edward
Published: April 2017

Objective To describe the prenatal diagnosis of Galen vein aneurysm (GVA) based on ultrasonography and magnetic resonance imaging (MRI) in a series of cases, as well as its postnatal outcomes and follow-up until 4 years of age.

Methods A retrospective longitudinal study was performed, analyzing a database comprising seven cases of prenatal diagnosis of GVA at two Brazilian institutions from February of 2000 to May of 2012. The following data were evaluated: gestational age at diagnosis, GVA dimensions on ultrasonography, associated fetal changes, findings on fetal echocardiography, gestational age at delivery, type of delivery, birth weight, Apgar score at the 1st and 5th minutes, neonatal outcomes, and survival with follow-up until 4 years of age.

Results The mean gestational age ± standard deviation on the prenatal diagnosis of GVA based on ultrasonography was 25 ± 4.9 weeks. The mean length of GVA was 3.2 ± 0.4 cm. The mean gestational age at birth was 37.5 ± 0.7 weeks, and a cesarean section was performed in 85.7% of the cases (6/7). The mean birth weight was 3,070 ± 240.4 g. The total survival rate was 42.8% (4/7), with three neonatal deaths. Of the four survivors, three presented with normal neuropsychomotor development until 4 years of age and only one showed serious neurological sequelae. Ultrasonography and MRI showed similar findings for all seven cases.

Conclusions Galen Vein Aneurysm is associated with a high neonatal death rate. Therefore, its prenatal diagnosis is essential for parent counseling and follow-up at tertiary care institutions.
Die bipolare Stimulation kann die Erfolgsrate des Peripheren Nervenevaluationstests der sakralen Neuromodulation verbessern
Authors: Reitz André , Hüsch Tanja , Doggweiler Regula , Buse Stephan , Haferkamp Axel
Published: April 2017

Fragestellung Die vorliegende Studie vergleicht die unipolare und die bipolare Stimulationstechnik während des Peripheren Nervenevaluationstestes der Sakralen Neuromodulation in einer Kohorte von 100 Patienten mit nicht-neurogenen und neurogenen Harntraktfunktionsstörungen und überprüft die Hypothese, dass die bipolare Technik der unipolaren bezogen auf die Testeffektivität überlegen ist.

Material und Methoden In diese Fall-Kontroll-Studie wurden 43 Patienten mit biopolarer und 57 Patienten mit unipolarer Stimulation eingeschlossen. Für die bipolare Stimulation wurden vier Elektroden an S3 und S4 beidseits platziert und die Elektroden von S3 und S4 jeder Seite elektrisch verbunden. In einem Testprotokoll über acht Tage wurde die Wirksamkeit der Stimulation überprüft. Nach Ende der Testphase wurden die Elektroden entfernt und das Ergebnis mit Hilfe der Miktionstagebücher ermittelt. Als Vergleichsgruppe diente eine Kohorte mit 57 Patienten und unipolarer Stimulation (aktive Elektrode an der Sakralwurzel und passive Elektrode auf der Haut).

Results Das unipolare Testverfahren war erfolgreich in 47 % (27 /57), das bipolare in 58 % (25 /43). In der bipolaren Gruppe profitierten 63 % (12/19) mit neurogener Harntraktfunktionsstörung vs. 57 % (13/23) in der unipolaren Gruppe. Ohne neurologisches Leiden wiesen bei bipolarer 58 % (14/24) einen erfolgreichen Test auf vs. 41 % (14/24) bei unipolarer Stimulation. Eine Multivarianzanalyse zeigte jedoch keinen statistisch signifikanten Unterschied zwischen den Gesamt- und Untergruppen.

Schlussfolgerung Auch wenn nicht statistisch signifikant, so zeigte sich bei bipolarer Stimulation eine höhere Erfolgsrate als bei der unipolaren Stimulation. Auch bei der Analyse der Subgruppen mit neurogener und nicht neurogener Harntraktfunktionsstörung zeigten sich ähnliche Ergebnisse. Eine größere Serie bei nicht neurogen bedingter Drang/Dranginkontinenz oder Retention kann möglicherweise in Zukunft klären, ob mit der bipolaren Stimulation eine Erfolgsrate auf dem Niveau der zweistufigen Implantation erzielt werden kann.
Transient Severe Motion Artifact Related to Gadoxetate Disodium-Enhanced Liver MRI: Frequency and Risk Evaluation at a German Institution
Authors: Well Lennart , Rausch Vanessa , Adam Gerhard , Henes Frank , Bannas Peter
Published: April 2017

Purpose Varying frequencies (5 – 18 %) of contrast-related transient severe motion (TSM) imaging artifacts during gadoxetate disodium-enhanced arterial phase liver MRI have been reported. Since previous reports originated from the United States and Japan, we aimed to determine the frequency of TSM at a German institution and to correlate it with potential risk factors and previously published results.

Materials and Methods Two age- and sex-matched groups were retrospectively selected (gadoxetate disodium n = 89; gadobenate dimeglumine n = 89) from dynamic contrast-enhanced MRI examinations in a single center. Respiratory motion-related artifacts in non-enhanced and dynamic phases were assessed independently by two readers blinded to contrast agents on a 4-point scale. Scores of ≥ 3 were considered as severe motion artifacts. Severe motion artifacts in arterial phases were considered as TSM if scores in all other phases were < 3. Potential risk factors for TSM were evaluated via logistic regression analysis.

Results For gadoxetate disodium, the mean score for respiratory motion artifacts was significantly higher in the arterial phase (2.2 ± 0.9) compared to all other phases (1.6 ± 0.7) (p < 0.05). The frequency of TSM was significantly higher with gadoxetate disodium (n = 19; 21.1 %) than with gadobenate dimeglumine (n = 1; 1.1 %) (p < 0.001). The frequency of TSM at our institution is similar to some, but not all previously published findings. Logistic regression analysis did not show any significant correlation between TSM and risk factors (all p > 0.05).

Conclusion We revealed a high frequency of TSM after injection of gadoxetate disodium at a German institution, substantiating the importance of a diagnosis-limiting phenomenon that so far has only been reported from the United States and Japan. In accordance with previous studies, we did not identify associated risk factors for TSM.

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Citation Format
Patient-reported adverse events after colonoscopy in Norway
Authors: Hoff Geir , de Lange Thomas , Bretthauer Michael , Buset Magne , Dahler Stein , Halvorsen Fred-Arne , Halwe Jörg , Heibert Mathis , Høie Ole , Kjellevold Øystein , Moritz Volker , Sandvei Per , Seip Birgitte , Aabakken Lars , Holme Øyvind
Published: April 2017

Background and aims Patient-reported outcome measures are increasingly important in healthcare. European guidelines have recommended inclusion of patient feedback to capture adverse events due to colonoscopy, but this is rarely implemented.

Methods The Norwegian Quality Assurance network for endoscopy (Gastronet) collects patient-reported outcome for colonoscopies. Free-text comments on patient reports from January to December 2015 were characterized as positive or negative. All negative free-text comments were scrutinized for information that might suggest colonoscopy-related adverse events. We identified severe adverse events with and without admission to hospital.

Results We included 16 552 outpatient colonoscopies performed at 21 hospitals. A total of 11 248 procedures (68 %) were accompanied by a patient feedback report, of which 2628 (23 %) had free-text comments (2196 [20 %] characterized as positive and 432 [3.8 %] as negative). These negative free texts on patient reports revealed 15 post-colonoscopy hospital admissions due to adverse events that had not been registered in the colonoscopy report. This increased the number of hospital admissions caused by adverse events from 3 (0.03 %) to 18 (0.16 %). In addition, there were 14 patient reports of severe events without hospital admission. Therefore, a total of 29 severe adverse events reported by patients were missed by conventional documentation in the colonoscopy form.

Conclusion It is feasible to implement patient feedback as routine reporting to capture the full picture of colonoscopy-related adverse events. Some patients experience significant complications that are not recorded through any registries. Patient feedback forms should be tailored to capture adverse events after colonoscopy that are otherwise not easily disclosed.
Algorithmic characterization results for the Kerr-NUT-(A)dS space-time. I. A space-time approach
Authors: Paetz Tim-Torben
Published: April 2017

We provide an algorithm to check whether a given vacuum space-time (M,g) admits a Killing vector field with respect to which the Mars-Simon tensor vanishes. In particular, we obtain an algorithmic procedure to check whether (M,g) is locally isometric to a member of the Kerr-NUT-(A)dS family. A particular emphasis will be devoted to the Kerr-(A)dS case.
Expansion of Titan atmosphere
Authors: Salem S. , Moslem W. M. , Radi A.
Published: April 2017

Self-similar plasma expansion approach is used to solve a plasma model based on the losing phenomenon of Titan atmospheric composition. To this purpose, a set of hydrodynamic fluid equations describing a plasma consisting of two positive ions with different masses and isothermal electrons is used. With the aid of self-similar transformation, numerical solution of the fluid equations has been performed to examine the density, velocity, and potential profiles. The effects of different plasma parameters, i.e., density and temperature ratios, are studied on the expanding plasma profiles. The present investigation could be useful to recognize the ionized particles escaping from Titan atmosphere.
Optimized radiation-hardened erbium doped fiber amplifiers for long space missions
Authors: Ladaci A. , Girard S. , Mescia L. , Robin T. , Laurent A. , Cadier B. , Boutillier M. , Ouerdane Y. , Boukenter A.
Published: April 2017

In this work, we developed and exploited simulation tools to optimize the performances of rare earth doped fiber amplifiers (REDFAs) for space missions. To describe these systems, a state-of-the-art model based on the rate equations and the particle swarm optimization technique is developed in which we also consider the main radiation effect on REDFA: the radiation induced attenuation (RIA). After the validation of this tool set by confrontation between theoretical and experimental results, we investigate how the deleterious radiation effects on the amplifier performance can be mitigated following adequate strategies to conceive the REDFA architecture. The tool set was validated by comparing the calculated Erbium-doped fiber amplifier (EDFA) gain degradation under X-rays at ∼300 krad(SiO2) with the corresponding experimental results. Two versions of the same fibers were used in this work, a standard optical fiber and a radiation hardened fiber, obtained by loading the previous fiber with hydrogen gas. Based on these fibers, standard and radiation hardened EDFAs were manufactured and tested in different operating configurations, and the obtained data were compared with simulation data done considering the same EDFA structure and fiber properties. This comparison reveals a good agreement between simulated gain and experimental data (<10% as the maximum error for the highest doses). Compared to our previous results obtained on Er/Yb-amplifiers, these results reveal the importance of the photo-bleaching mechanism competing with the RIA that cannot be neglected for the modeling of the radiation-induced gain degradation of EDFAs. This implies to measure in representative conditions the RIA at the pump and signal wavelengths that are used as input parameters for the simulation. The validated numerical codes have then been used to evaluate the potential of some EDFA architecture evolutions in the amplifier performance during the space mission. Optimization of both the fiber length and the EDFA pumping scheme allows us to strongly reduce its radiation vulnerability in terms of gain. The presented approach is a complementary and effective tool for hardening by device techniques and opens new perspectives for the applications of REDFAs and lasers in harsh environments.
Density functional investigation of the adsorption effects of PH3 and SH2 on the structure stability of the Au55 and Pt55 nanoclusters
Authors: Guedes-Sobrinho Diego , Chaves Anderson S. , Piotrowski Maurício J. , Da Silva Juarez L. F.
Published: April 2017

Although several studies have been reported for Pt55 and Au55 nanoclusters, our atomistic understanding of the interplay between the adsorbate-surface interactions and the mechanisms that lead to the formation of the distorted reduced core (DRC) structures, instead of the icosahedron (ICO) structure in gas phase, is still far from satisfactory. Here, we report a density functional theory (DFT) investigation of the role of the adsorption effects of PH3 (one lone pair of electrons) and SH2 (two lone pairs) on the relative stability of the Pt55 and Au55 nanoclusters. In gas phase, we found that the DRC structures with 7 and 9 atoms in the core region are about 5.34 eV (Pt55) and 2.20 eV (Au55) lower in energy than the ICO model with Ih symmetry and 13 atoms in the core region. However, the stability of the ICO structure increases by increasing the number of adsorbed molecules from 1 to 18, in which both DRC and ICO structures are nearly degenerate in energy at the limit of 18 ligands, which can be explained as follows. In gas phase, there is a strong compression of the cationic core region by the anionic surface atoms induced by the attractive Coulomb interactions (core+-surface−), and hence, the strain release is obtained by reducing the number of atoms in the cationic core region, which leads to the 55 atoms distorted reduced core structures. Thus, the Coulomb interactions between the core+ and surface− contribute to break the symmetry in the ICO55 structure. On the other hand, the addition of ligands on the anionic surface reduces the charge transfer between the core and surface, which contributes to decrease the Coulomb interactions and the strain on the core region of the ICO structure, and hence, it stabilizes a compact ICO structure. The same conclusion is obtained by adding van der Waals corrections to the plain DFT calculations. Similar results are obtained by the addition of steric effects, which are considered through the adsorption of triphenylphosphine (PPh3) molecules on Au55, in which the relative stability between ICO and DRC is the same as for PH3 and SH2. However, for Pt55, we found an inversion of stability due to the PPh3 ligand effects, where ICO has higher stability than DRC by 2.40 eV. Our insights are supported by several structural, electronic, and energetic analyses.
Vector semirational rogue waves and modulation instability for the coupled higher-order nonlinear Schrödinger equations in the birefringent optical fibers
Authors: Sun Wen-Rong , Liu De-Yin , Xie Xi-Yang
Published: April 2017

We report the existence and properties of vector breather and semirational rogue-wave solutions for the coupled higher-order nonlinear Schrödinger equations, which describe the propagation of ultrashort optical pulses in birefringent optical fibers. Analytic vector breather and semirational rogue-wave solutions are obtained with Darboux dressing transformation. We observe that the superposition of the dark and bright contributions in each of the two wave components can give rise to complicated breather and semirational rogue-wave dynamics. We show that the bright-dark type vector solitons (or breather-like vector solitons) with nonconstant speed interplay with Akhmediev breathers, Kuznetsov-Ma solitons, and rogue waves. By adjusting parameters, we note that the rogue wave and bright-dark soliton merge, generating the boomeron-type bright-dark solitons. We prove that the rogue wave can be excited in the baseband modulation instability regime. These results may provide evidence of the collision between the mixed ultrashort soliton and rogue wave.
Thermodynamics of mixtures of patchy and spherical colloids of different sizes: A multi-body association theory with complete reference fluid information
Authors: Bansal Artee , Valiya Parambathu Arjun , Asthagiri D. , Cox Kenneth R. , Chapman Walter G.
Published: April 2017

We present a theory to predict the structure and thermodynamics of mixtures of colloids of different diameters, building on our earlier work [A. Bansal et al., J. Chem. Phys. 145, 074904 (2016)] that considered mixtures with all particles constrained to have the same size. The patchy, solvent particles have short-range directional interactions, while the solute particles have short-range isotropic interactions. The hard-sphere mixture without any association site forms the reference fluid. An important ingredient within the multi-body association theory is the description of clustering of the reference solvent around the reference solute. Here we account for the physical, multi-body clusters of the reference solvent around the reference solute in terms of occupancy statistics in a defined observation volume. These occupancy probabilities are obtained from enhanced sampling simulations, but we also present statistical mechanical models to estimate these probabilities with limited simulation data. Relative to an approach that describes only up to three-body correlations in the reference, incorporating the complete reference information better predicts the bonding state and thermodynamics of the physical solute for a wide range of system conditions. Importantly, analysis of the residual chemical potential of the infinitely dilute solute from molecular simulation and theory shows that whereas the chemical potential is somewhat insensitive to the description of the structure of the reference fluid, the energetic and entropic contributions are not, with the results from the complete reference approach being in better agreement with particle simulations.
Magnetization dynamics and damping behavior of Co/Ni multilayers with a graded Ta capping layer
Authors: Jaris M. , Lau D. , Sokalski V. , Schmidt H.
Published: April 2017

Magnetization dynamics of a Co/Ni multilayer film capped by a wedged Ta (0.3–1.3 nm) layer were investigated using time-resolved magneto-optic Kerr microscopy. The ferromagnetic resonance was observed for a wide range of magnetic fields in a variety of geometries. Using a macrospin approximation and the Kittel formula to evaluate the relaxation frequency, a significant increase of the effective anisotropy field was observed as the Ta layer thickness is increased. Furthermore, the damping behavior of the magnetization precession also shows a strong dependence on the Ta layer thickness. Using a model to account for variations of the local anisotropy fields, we reproduce the field evolution of the observed damping using a single Gilbert damping parameter for the Co/Ni system. These findings have direct implications for the rational design of novel spintronic devices.
Influence of the inter-electrode gap on the cathode sheath characteristics (voltage drop across it and its thickness)
Authors: Lisovskiy V. A. , Artushenko K. P. , Yegorenkov V. D.
Published: April 2017

This paper is devoted to studying how the inter-electrode distance affects the voltage drop across electrodes, the cathode sheath thickness, and the axial distribution of plasma parameters. The experiment demonstrates the simultaneous growth of both the voltage drop across the electrodes and the cathode sheath thickness when on increasing the gap the anode is moved away from the cathode while remaining in the negative glow. This effect is most clearly pronounced under low gas pressure and high current values when the negative glow length is large. The discharge axial structure dynamics is studied with the Langmuir probe technique and with the OOPIC Pro code. The inter-electrode gap growth with the current fixed is found to be accompanied by the plasma concentration increase in the negative glow. The positive plasma potential is shown to cause the current to the grounded anode to be transported by fast electrons accelerated in the cathode sheath. Moving the anode away from the cathode through the negative glow weakens the flow of fast electrons coming to the anode, thus decreasing the discharge current. In order to restore the discharge current, one has to increase the voltage across the electrodes, leading to the cathode sheath thickness increase and the plasma concentration growth in the negative glow.
Two-dimensional numerical simulation of a continuous needle-like argon electron-beam plasma
Authors: Bai Xiaoyan , Chen Chen , Li Hong , Liu Wandong
Published: April 2017

The fluid-Poisson equations coupled with the Monte Carlo method were used to simulate the spatio-temporal behavior of a needle-like argon electron-beam plasma. Based on the Monte Carlo simulation, three coupled parameters characterizing the electron beam propagation for initial energies above several keV were expressed using a universal dimensionless shape function given in terms of the beam range multiplied by a normalized coefficient. Therefore, a single run of the Monte Carlo code was sufficient for the simulations over a wide range of conditions. The spatial potential as a function of space and time was studied from the fluid-Poisson equations. The results indicate that the time evolution of the spatial potential was influenced by the presence of the slowed-down electrons and the flying beam electrons, whereas the potential in quasi-equilibrium was mainly determined from the spatial distribution of the secondary electron. The potential in quasi-equilibrium was positive near the beam entrance and most negative along the tip of the beam range, which was a result of ambipolar diffusion. When the enclosing boundary surfaces were moved within the beam range, the potential was nearly positive everywhere. The calculation on the diffusion-drift flux indicated that the net current of the secondary electrons flowing back to the incident plane in quasi-equilibrium balanced the incident beam current, which was the so-called return current in the three-dimensional space.
Spall fracture and twinning in laser shock-loaded single-crystal magnesium
Authors: de Rességuier T. , Hemery S. , Lescoute E. , Villechaise P. , Kanel G. I. , Razorenov S. V.
Published: April 2017

As a major failure process in materials subjected to dynamic loading, spall fracture is one of the most widely studied issues in shock physics. To investigate its dependence on the microstructure, including both initial and shock-induced features, laser shock experiments were performed on single crystal magnesium. Shock loading was applied in directions parallel and perpendicular to the c-axis of the crystals. Both the spall strength and the fracture surface morphology are found to depend on the direction of the shock application with respect to crystal orientations. The results complement data obtained previously over ranges of lower strain rates. A detailed analysis of the residual microstructure and crack patterns in the recovered samples shows strong correlations between damage localization and twins, both pre-existing and shock-induced. Thus, cracks match specific twinning directions, which is discussed on the basis of deformation mechanisms reported under quasi-static loading conditions, either prismatic slip or twinning depending on local orientations.
Algal biotechnology for pursuing omega-3 fatty acid (bioactive) production
Authors: Puri Munish
Published: April 2017

Algae are spread in diversified ecosystems that include marine, freshwater, desert and hot springs and even snow and ice environments. Algae are classified as multicellular large sea weeds (macroalgae) or unicellular microalgae. Macroalgae are targeted for mining of natural biologically active components, which include proteins, linear peptides, cyclic peptides, and amino acids1. Recently, microalgae have been exploited for the production of high-value compounds such as lipids (omega-3 fatty acids), enzymes, polymers, toxins, antioxidants, and pigments (carotenoids)2. Thus, algal biotechnology is defined as ‘the technology developed using algae (macro or micro) to make or modify bioactive compounds, or products (nutritional supplements, fine chemicals) and renewable fuels for specific use’.
Protective effects of polydatin on experimental testicular torsion and detorsion injury in rats
Authors: Qiao Huilian , Ma He , Cao Wanjun , Chen Hao , Wei Jinhua , Li Zhen
Published: April 2017

Oxidative stress plays a critical role in the process of testicular torsion and detorsion (T/D). The purpose of the present study was to investigate the protective effect of polydatin (PD) on testicular T/D injury. Rats were randomly divided into three groups, a sham group, a group subjected to 2 h torsion followed by 24 h detorsion and a group subjected to T/D and injected i.p. with 20 mg kg−1 PD 30 min before detorsion. Unilateral orchiectomy was performed after 24 h of reperfusion. Half the testes were prepared for histological examination by haematoxylin–eosin staining and the terminal deoxyribonucleotidyl transferase-mediated dUTP–digoxigenin nick end-labelling (TUNEL) technique. In the remaining tissues, levels of malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) were determined, as was the expression of several apoptosis-related proteins. Compared with the T/D group, PD pretreatment significantly ameliorated the morphological damage, lowered the Cosentino histological score and increased the mean number of germ cell layers and Johnsen’s testicular biopsy score. In addition, PD treatment markedly decreased MDA levels and upregulated CAT, GPx and SOD activity. Furthermore, PD decreased T/D-induced germ cell-specific apoptosis, attenuated the activation of caspase-3, caspase-8, caspase-9 and poly(ADP-ribose) polymerase and increased the Bcl-2/Bax ratio. The findings indicate that PD has a protective effect against testicular T/D injuries, especially at the histological, antioxidative stress and antiapoptotic levels.
Disturbance-dependent invasion of the woody weed, Calotropis procera, in Australian rangelands
Authors: Menge Enock O. , Bellairs Sean M. , Lawes Michael J.
Published: April 2017

Plant invasions are threats to biodiversity and ecosystem processes that have far reaching ecological and economic impacts. Understanding the mechanisms of invasion essentially helps in developing effective management strategies. Rubber bush (Calotropis procera) is an introduced milkweed that invades Australian beef production rangelands. Its establishment is often associated with disturbances caused by pastoral management practices. We examined whether or not rubber bush (1) outcompetes native grasses, (2) can invade intact rangeland, and (3) if disturbance facilitates rubber bush establishment and spread in grassy rangelands. We measured the competitive response of different densities of Mitchell grass (Astrebla pectinata) individuals and the competitive effects of associate rubber bush seedlings in an additive common garden experiment. Replicated field exclosure experiments, under grass-dominated and tropical savanna woodland conditions examined the effect of increasing levels of disturbance on rubber bush seedling emergence. The dominant native Mitchell grass was a stronger competitor than rubber bush when grown together under greenhouse conditions, whereby root and shoot biomass yields were more restricted in rubber bush compared with Mitchell grass. This finding was corroborated in the field exclosure experiments at both sites, where seedling emergence increased 5-fold in seeded and highly disturbed plots where superficial soils were turned over by treatments simulating heavy grazing and trampling by cattle or machinery. Emergence of rubber bush seedlings in seeded plots that were undisturbed, clipped and grazed was minimal and rubber bush seedlings did not survive the seedling stage in these plots. These results demonstrate that disturbance to the superficial soil stratum affects the ability of rubber bush seeds to successfully establish in a microsite, and high levels of soil disturbance substantially increase establishment. Thus, rubber bush is a poor competitor of Mitchell grass and does not invade intact grassland. Consequently, rubber bush invasion is disturbance-dependent in the vast Australian rangelands. The spread of this weed may be arrested by management practices that minimise disturbances to grass cover.
Early development of eel-tailed catfish, Tandanus tandanus (Mitchell) (Teleostei : Plotosidae), with validation of daily otolith increment formation
Authors: Burndred K. R. , Cockayne B. J. , Lou D. C.
Published: April 2017

Eel-tailed catfish, Tandanus tandanus, have recently experienced widespread population declines in eastern Australia; with some southern populations facing the risk of extinction, the management and conservation of Queensland populations should be considered a priority. There is a lack of sound, scientific knowledge surrounding the species’ reproductive patterns and early life-history requirements. To assist in clarifying the influence of changes to the natural environment on the reproductive ecology of T. tandanus, we investigated their early life history using naturally fertilised eggs and larvae from a wild population. Nest depth ranged from 0.20 m to 1.35 m, with in situ temperatures between 15.1°C and 29.9°C, and in situ velocities from 0.00 to 0.52 ms–1. Eggs ranged in diameter from 2.6 to 4.0 mm throughout development, and preservation of eggs in ethanol caused significant shrinkage (mean 18.9%). Hatching took 4–7 days (mean 5.29 days; 15.7–28.0°C). Larvae collected from nests ranged in length from 5.1 mm to 15.3 mm SL, and in age from one day old to 16 days old. Larvae are likely to actively disperse from their nest at ~16 days old, as they approach juvenile metamorphosis. Daily otolith increment formation was validated up to 28 days after hatching; and sagittal otoliths were used to develop an age–length relationship for larvae. These results can assist researchers in estimating the timing of critical recruitment events, and investigating how the species’ early life history is influenced by environmental conditions.
Procrastination, Health, and Health Risk Communication
Authors: Sirois Fuschia M.
Published: April 2017

Whether viewed as a domain-specific behavior or as an enduring tendency, procrastination is a common form of self-regulation failure that is increasingly recognized as having implications for health-related outcomes. Central to procrastination is the prioritization of reducing immediate negative mood at the cost of decisions and actions that provide long-term rewards, such as engaging in health behaviors. Because people tend to procrastinate on tasks they find difficult, unpleasant, or challenging, many health-promoting behaviors are possible candidates for procrastination. As modifiable risk factors for the prevention of disease and disability, health behaviors are often the target of health risk communications aimed at health behavior change and reducing health procrastination. Research has consistently demonstrated the deleterious effects of chronic procrastination on health outcomes, including poor physical health, fewer health promoting behaviors, and higher stress in healthy adults and those already living with a chronic health condition.

Examining the factors and psychological characteristics associated with chronic procrastination can provide insights into the processes involved in procrastination more generally, as well as the qualities of the health messages that can promote or prevent procrastination of the targeted behaviors. Low future orientation, avoidant coping, low tolerance for negative emotions, and low self-efficacy need to be considered when designing effective health risk communications to reduce procrastination of health behaviors. Yet, health risk communications aimed at reducing procrastination of important health behaviors such as healthy eating, regular physical activity, screening behaviors, and cessation of risky health behaviors often use fear appeals to motivate taking protective actions to reduce health risks. Such approaches may not be effective because they amplify the negative feelings towards the health behaviors, which can engender maladaptive coping responses and motivate procrastination rather than adaptive responding. This is especially likely among individuals prone to procrastination more generally, or specifically with respect to health. Health risk communication approaches that minimize the negative emotions associated with risk messages and instead highlight short-term benefits of engaging in health behaviors may be necessary to reduce further health behavior procrastination among individuals prone to this form of self-regulation failure.