bluuebunny/crossref_metadata_2025 huggingface dataset:
Minimum‐copper‐loss control of hybrid excited axial field flux‐switching machine
Authors: Zhao Jilong , Lin Mingyao , Xu Da
Published: November 2015

Hybrid excited axial field flux‐switching machine (HEAFFSM) with permanent magnets (PMs) and excitation windings in its stator is a novel hybrid excited flux‐switching PM machine. The HEAFFSM combines the advantages of the hybrid excited synchronous machine and flux‐switching PM machine. In this study, the topology and operating principles of the HEAFFSM are analysed, and the electromagnetic characteristics (including the winding inductances, flux, and cogging torque) are obtained by the three‐dimensional finite‐element method. On the basis of the vector control method, the mathematical model of the HEAFFSM is deduced, and the operating performance of the HEAFFSM across its entire operating range is investigated. A new minimum‐copper‐loss (MCL) control strategy for the HEAFFSM drive system, which can operate in both flux‐enhancing and flux‐weakening conditions, is proposed and compared with the traditional control. The experimental results demonstrate that the MCL strategy maximises the range of speed regulation while minimises the copper loss of the HEAFFSM drive system. Moreover, the flux‐regulation capability and high power/torque density of the HEAFFSM are validated.
Control design and experimental verification of the brushless doubly‐fed machine for stand‐alone power generation applications
Authors: Liu Yi , Ai Wu , Chen Bing , Chen Ke , Luo Guang
Published: November 2015

In this study, a control scheme for the stand‐alone generation system based on brushless doubly‐fed machine (BDFM) is presented. The output voltage amplitude and frequency are kept constant under variable rotor speed and load by regulating the amplitude and frequency of the control winding (CW) current of BDFM appropriately. The control scheme utilises a CW current vector controller as the inner loop, and a power winding voltage amplitude controller and a frequency controller as the outer loop. The proposed control scheme has been implemented on a prototype BDFM designed for the variable‐speed stand‐alone ship shaft generation application. Moreover, the satisfactory dynamic performance and low total harmonic distortion of the output voltage in the proposed stand‐alone generation system is verified by experiments with two kinds of typical loads: three‐phase induction motor load and three‐phase RL inductive load.
Finite element modelling of turbine generator stator end windings for vibration analysis
Authors: Iga Yoshihiko , Takahashi Kazuhiko , Yamamoto Yukihiro
Published: November 2015

In this study, the authors present methods for accurately modelling the bindings and the stator bars of turbine generator stator end windings for vibration analyses. The bindings are modelled with beam elements and multipoint constraint equations to take account of the bending, twisting, and shearing rigidities of the bindings. To reproduce the spatial distribution of rigidity in a cross‐section of the stator bar, the bar is modelled as a composite material comprising a conductor bar with equivalent elastic moduli and ground insulation. The accuracies of the developed binding and stator bar models are verified by comparing measured natural frequencies of binding test pieces and stator bar specimens with calculated values. The developed models and conventional models are applied to the natural frequency analyses of stator end windings, and then the effects of the modelling methods on the calculation accuracy are investigated. While the maximum calculation errors of the conventional models are more than 12%, the calculation results of the developed models agree with the measured values within an error of 7%. Accordingly, for accurately calculating the end winding natural frequencies, end winding finite element models need to take the binding rigidities into account and reproduce the rigidity distribution of the stator bar.
Analysis and simplified modelling of brushless doubly‐fed induction machine in synchronous mode of operation
Authors: Tohidi Sajjad
Published: November 2015

Similar to conventional doubly‐fed induction machines (DFIMs), brushless DFIM (BDFIM) obtains variable speed operation by means of a fractionally rated converter. Due to its brushless structure, BDFIM confers higher reliability and requires lower maintenance than the conventional DFIMs. Hence, it has potential future use in offshore wind turbines. This study elaborates the most attractive mode of BDFIM operation, i.e. the synchronous mode. The BDFIM air‐gap flux is complex due to the presence of spatial harmonic components with different pole numbers. To facilitate analysis of the BDFIM performance, this study aims to simplify its steady state and dynamic models. To achieve this goal, the BDFIM electromagnetic torque is analysed to induction and synchronous components. Then, considering the share of each torque components, simplifications are proposed in the steady state and dynamic models of BDFIM. Thus, the BDFIM model becomes similar to conventional DFIMs. The equivalent parameters of the proposed simplified model of BDFIM and the model of conventional DFIMs are introduced. Supplementary experiments and simulations are carried out for a prototype D180 4/8 pole BDFIM.
Primary Aldosteronism: New Answers, New Questions
Authors: Funder J. W.
Published: November 2015

There have been 2, and possibly 3, major questions for primary aldosteronism (PA)
answered at least in principle over the past 5 years. The first is that of
somatic mutations underlying the majority of aldosterone producing adenomas. The
second is the extension of our knowledge of the genetics of familial
hypertension, and the third the role of renal intercalated cells in sodium
homeostasis. New questions for the next 5 years include a single accepted
confirmatory/exclusion test; standardisation of assays and cut-offs;
alternatives to universal adrenal venous sampling; reclassification of ‘low
renin hypertension’; recognition of the extent of ‘occult’ PA; inclusion of
low-dose mineralocorticoid receptor antagonist in first-line therapy for
hypertension; and finally, possible resolution of the aldosterone/inappropriate
sodium status enigma at the heart of the cardiovascular damage in PA.
The role of non-specific interactions in a patchy model of protein crystallization
Authors: Staneva Iskra , Frenkel Daan
Published: November 2015

We use a coarse-grained model for generic proteins to investigate the formation of structures with P212121 symmetry, the most prevalent space group of protein crystals. To account for the string directionality of protein-protein interactions that has been suggested by previous studies, we represent proteins as spherical particles that are covered by a large number of small, attractive “patches” that are randomly distributed on the protein surface. Attractive interactions between two proteins can then involve several pairs of patches interacting simultaneously. Our results suggest that the unit cell with the lowest energy is not necessarily the one that grows fastest. Rather, growth is favoured if 1) new particles can attach with enough bonds to the growth front and 2) particles that attach in crystallographically inequivalent positions bind to the surface with similar strength. We subsequently study the impact of interactions that are not part of crystalline contacts and find that when these non-specific interactions are few and weaker than the crystal contacts, both nucleation and growth are successful. If the proportion of non-specific interactions is increased, crystal growth is still possible in a small range of model temperature.
Calculation of correlated initial state in the hierarchical equations of motion method using an imaginary time path integral approach
Authors: Song Linze , Shi Qiang
Published: November 2015

Based on recent findings in the hierarchical equations of motion (HEOM) for correlated initial state [Y. Tanimura, J. Chem. Phys. 141, 044114 (2014)], we propose a new stochastic method to obtain the initial conditions for the real time HEOM propagation, which can be used further to calculate the equilibrium correlation functions and symmetrized correlation functions. The new method is derived through stochastic unraveling of the imaginary time influence functional, where a set of stochastic imaginary time HEOM are obtained. The validity of the new method is demonstrated using numerical examples including the spin-Boson model, and the Holstein model with undamped harmonic oscillator modes.
Conditions for forming composite carbon nanotube-diamond like carbon material that retain the good properties of both materials
Authors: Ren Wei , Iyer Ajai , Koskinen Jari , Kaskela Antti , Kauppinen Esko I. , Avchaciov Konstantin , Nordlund Kai
Published: November 2015

Carbon nanotubes are of wide interest due to their excellent properties such as tensile strength and electrical and thermal conductivity, but are not, when placed alone on a substrate, well resistant to mechanical wear. Diamond-like carbon (DLC), on the other hand, is widely used in applications due to its very good wear resistance. Combining the two materials could provide a very durable pure carbon nanomaterial enabling to benefit from the best properties of both carbon allotropes. However, the synthesis of high-quality diamond-like carbon uses energetic plasmas, which can damage the nanotubes. From previous works it is neither clear whether the quality of the tubes remains good after DLC deposition, nor whether the DLC above the tubes retains the high sp3 bonding fraction. In this work, we use experiments and classical molecular dynamics simulations to study the mechanisms of DLC formation on various carbon nanotube compositions. The results show that high-sp3-content DLC can be formed provided the deposition conditions allow for sidewards pressure to form from a substrate close beneath the tubes. Under optimal DLC formation energies of around 40–70 eV, the top two nanotube atom layers are fully destroyed by the plasma deposition, but layers below this can retain their structural integrity.
Peristaltic pump-based low range pressure sensor calibration system
Authors: Vinayakumar K. B. , Naveen Kumar G. , Nayak M. M. , Dinesh N. S. , Rajanna K.
Published: November 2015

Peristaltic pumps were normally used to pump liquids in several chemical and biological applications. In the present study, a peristaltic pump was used to pressurize the chamber (positive as well negative pressures) using atmospheric air. In the present paper, we discuss the development and performance study of an automatic pressurization system to calibrate low range (millibar) pressure sensors. The system includes a peristaltic pump, calibrated pressure sensor (master sensor), pressure chamber, and the control electronics. An in-house developed peristaltic pump was used to pressurize the chamber. A closed loop control system has been developed to detect and adjust the pressure leaks in the chamber. The complete system has been integrated into a portable product. The system performance has been studied for a step response and steady state errors. The system is portable, free from oil contaminants, and consumes less power compared to existing pressure calibration systems. The veracity of the system was verified by calibrating an unknown diaphragm based pressure sensor and the results obtained were satisfactory.
Evaporation, viscous flow, and electrostatic interaction of charged interfaces in the apparent contact line region
Authors: Ketelaar Christiaan , Ajaev Vladimir S.
Published: November 2015

We consider evaporation of an aqueous solution near an apparent contact line separating a macroscopically dry area of a heated solid substrate and a constant-curvature meniscus far away from the substrate. Viscous flow, described by a lubrication-type model, is coupled to the interaction of electrical double layers formed near the solid-liquid and liquid-vapor interfaces. The electrostatic interaction is described using the nonlinear Poisson-Boltzmann equation and is shown to affect both normal and shear stress balances at the deformable interface. For steady configurations, we find that the apparent contact line region becomes wider and the total evaporation rate there increases as the substrate potential is increased. Motion of the apparent contact line in response to changes in the substrate temperature is also investigated. The contact line speed is found to increase when the electrostatic effects are incorporated into the model.
A singly charged ion source for radioactive 11C ion acceleration
Authors: Katagiri K. , Noda A. , Nagatsu K. , Nakao M. , Hojo S. , Muramatsu M. , Suzuki K. , Wakui T. , Noda K.
Published: November 2015

A new singly charged ion source using electron impact ionization has been developed to realize an isotope separation on-line system for simultaneous positron emission tomography imaging and heavy-ion cancer therapy using radioactive 11C ion beams. Low-energy electron beams are used in the electron impact ion source to produce singly charged ions. Ionization efficiency was calculated in order to decide the geometric parameters of the ion source and to determine the required electron emission current for obtaining high ionization efficiency. Based on these considerations, the singly charged ion source was designed and fabricated. In testing, the fabricated ion source was found to have favorable performance as a singly charged ion source.
Two-dimensional simulation of discharge channels in atmospheric-pressure single dielectric barrier discharges
Authors: Zhang Jiao , Wang Yanhui , Wang Dezhen
Published: November 2015

A two-dimensional fluid model is developed to study the filaments (or discharge channels) in atmospheric-pressure discharge with one plate electrode covered by a dielectric layer. Under certain discharge parameters, one or more stable filaments with wide radii could be regularly arranged in the discharge space. Different from the short-lived randomly distributed microdischarges, this stable and thick filament can carry more current and have longer lifetime. Because only one electrode is covered by a dielectric layer in the simulation, the formed discharge channel extends outwards near the dielectric layer and shrinks inwards near the naked electrode, agreeing with the experimental results. In this paper, the evolution of channel is studied, and its behavior is like a streamer or an ionization wave, but the propagation distance is short. The discharge parameters such as voltage amplitude, electrode width, and N2 impurities content could significantly influence the number of discharge channel, which is discussed in the paper.
Mechanisms of amplification of ultrashort electromagnetic pulses in gyrotron traveling wave tube with helically corrugated waveguide
Authors: Ginzburg N. S. , Zotova I. V. , Sergeev A. S. , Zaslavsky V. Yu. , Zheleznov I. V. , Samsonov S. V. , Mishakin S. V.
Published: November 2015

A time-domain self consistent theory of a gyrotron traveling wave tube with a helically corrugated operating waveguide has been developed. Based on this model, the process of short pulse amplification was studied in regimes of grazing and intersection of the dispersion curves of the electromagnetic wave and the electron beam. In the first case, the possibility of amplification without pulse form distortion was demonstrated for the pulse spectrum width of the order of the gain bandwidth. In the second case, when the electrons' axial velocity was smaller than the wave's group velocity, it was shown that the slippage of the incident signal with respect to the electron beam provides feeding of the signal by “fresh” electrons without initial modulation. As a result, the amplitude of the output pulse can exceed the amplitude of its saturated value for the case of the grazing regime, and, for optimal parameters, the peak output power can be even larger than the kinetic power of the electron beam.
Plasma viscosity with mass transport in spherical inertial confinement fusion implosion simulations
Authors: Vold E. L. , Joglekar A. S. , Ortega M. I. , Moll R. , Fenn D. , Molvig K.
Published: November 2015

The effects of viscosity and small-scale atomic-level mixing on plasmas in inertial confinement fusion (ICF) currently represent challenges in ICF research. Many current ICF hydrodynamic codes ignore the effects of viscosity though recent research indicates viscosity and mixing by classical transport processes may have a substantial impact on implosion dynamics. We have implemented a Lagrangian hydrodynamic code in one-dimensional spherical geometry with plasma viscosity and mass transport and including a three temperature model for ions, electrons, and radiation treated in a gray radiation diffusion approximation. The code is used to study ICF implosion differences with and without plasma viscosity and to determine the impacts of viscosity on temperature histories and neutron yield. It was found that plasma viscosity has substantial impacts on ICF shock dynamics characterized by shock burn timing, maximum burn temperatures, convergence ratio, and time history of neutron production rates. Plasma viscosity reduces the need for artificial viscosity to maintain numerical stability in the Lagrangian formulation and also modifies the flux-limiting needed for electron thermal conduction.
The development of coated and non-coated wire explosions observed by X-ray backlighting
Authors: Zhu Xinlei , Zhao Shen , Zou Xiaobing , Shi Huantong , Luo Haiyun , Wang Xinxin
Published: November 2015

Based on an X-pinch X-ray point source, the electrical explosion of coated and non-coated wires with 25 μm diameter was backlit. The experiments were performed on the pulsed power device PPG-1 (500 kV/400 kA/100 ns) which was designed and constructed by the Department of Electrical Engineering of Tsinghua University. The source X-pinch was installed between the main output electrodes, while the object coated and non-coated wires were placed at the positions of the left and right current return rods, respectively. The backlighting images were recorded by X-ray films with high resolution and sensitivity. By a large number of backlighting experiments, the exploding physical images and expansion ratio curves of the coated and non-coated wires were obtained, and the results showed that coating can make the wire expand to be larger and more uniform.
Lagrangian and Hamiltonian constraints for guiding-center Hamiltonian theories
Authors: Tronko Natalia , Brizard Alain J.
Published: November 2015

A consistent guiding-center Hamiltonian theory is derived by Lie-transform perturbation method, with terms up to second order in magnetic-field nonuniformity. Consistency is demonstrated by showing that the guiding-center transformation presented here satisfies separate Jacobian and Lagrangian constraints that have not been explored before. A new first-order term appearing in the guiding-center phase-space Lagrangian is identified through a calculation of the guiding-center polarization. It is shown that this new polarization term also yields a simpler expression of the guiding-center toroidal canonical momentum, which satisfies an exact conservation law in axisymmetric magnetic geometries. Finally, an application of the guiding-center Lagrangian constraint on the guiding-center Hamiltonian yields a natural interpretation for its higher-order corrections.
Hydrolysis of ammonia borane and metal amidoboranes: A comparative study
Authors: Banu Tahamida , Debnath Tanay , Ash Tamalika , Das Abhijit K.
Published: November 2015

A gas phase mechanistic investigation has been carried out theoretically to explore the hydrolysis pathway of ammonia borane (NH3BH3) and metal amidoboranes (MNH2BH3, M = Li,Na). The Solvation Model based on Density (SMD) has been employed to show the effect of bulk water on the reaction mechanism. Gibbs free energy of solvation has also been computed to evaluate the stabilization of the participating systems in water medium which directly affects the barrier heights in the potential energy surface of hydrolysis reaction. To validate the experimentally observed kinetics studies, we have carried out transition state theory calculations on these hydrolysis reactions. Our result shows that the hydrolysis of both the metal amidoboranes exhibits greatly improved kinetics over the neat NH3BH3 hydrolysis which corroborates well with the experimental observation. Between the two amidoboranes, hydrolysis of LiNH2BH3 is found to be kinetically favored over that of NaNH2BH3, making it a better candidate for releasing molecular hydrogen.
Activation of coherent lattice phonon following ultrafast molecular spin-state photo-switching: A molecule-to-lattice energy transfer
Authors: Marino A. , Cammarata M. , Matar S. F. , Létard J.-F. , Chastanet G. , Chollet M. , Glownia J. M. , Lemke H. T. , Collet E.
Published: November 2015

We combine ultrafast optical spectroscopy with femtosecond X-ray absorption to study the photo-switching dynamics of the [Fe(PM-AzA)2(NCS)2] spin-crossover molecular solid. The light-induced excited spin-state trapping process switches the molecules from low spin to high spin (HS) states on the sub-picosecond timescale. The change of the electronic state (<50 fs) induces a structural reorganization of the molecule within 160 fs. This transformation is accompanied by coherent molecular vibrations in the HS potential and especially a rapidly damped Fe-ligand breathing mode. The time-resolved studies evidence a delayed activation of coherent optical phonons of the lattice surrounding the photoexcited molecules.
Multi-objective optimization and fuzzy evaluation of a horizontal axis wind turbine composite blade
Authors: Gao Qiang , Cai Xin , Zhu Jie , Guo Xingwen
Published: November 2015

The aerodynamic and structural coupling optimization of a 1.5 MW wind turbine blade is conducted based on the multi-objective genetic algorithm NSGA-II. Through the optimization of the chord lengths, the twist angles, and the number of laminating, an optimal solution set is obtained, in which the blade is lighter and the generating capacity is higher. Particularly, the fuzzy evaluation is performed after the multi-objective optimization to select the best design adapting to the specific working environment. A new method to determine the membership is proposed instead of experts vote when the fuzzy evaluation is carried out, which contributes to decreasing subjectivity, and saving much time, human and material resources. Hopefully, the method combining the multi-objective optimization and the fuzzy evaluation can be applied to the other similar projects in engineering.
Insensitive high-energy energetic structural material of tungsten-polytetrafluoroethylene-aluminum composites
Authors: Wang Liu , Liu Jinxu , Li Shukui , Zhang Xinbo
Published: November 2015

Energetic structural material is a kind of materials that are inert under normal conditions but could produce exothermic chemical reaction when subjected to impact. This report shows a kind of energetic structural material of tungsten (W)-polytetrafluoroethylene (PTFE)-aluminum (Al) with density of 4.12 g/cm3, excellent ductility and dynamic compressive strength of 96 MPa. Moreover, 50W-35PTFE-15Al (wt%) can exhibit a high reaction energy value of more than 2 times of TNT per unit mass and 5 times of TNT per unit volume, respectively, but with excellent insensitivity compared with traditional explosives. Under thermal conditions, the W-PTFE-Al composite can keep stable at 773 K. Under impact loading, when the strain rate up to ∼4820 s−1 coupled with the absorbed energy per unit volume of 120 J/cm3, deflagration occurs and combustion lasts for 500 μs. During impact compressive deformation, the PTFE matrix is elongated into nano-fibers, thus significantly increases the reaction activity of W-PTFE-Al composites. The nano-fiber structure is necessary for the reaction of W-PTFE-Al composites. The formation of PTFE nano-fibers must undergo severe plastic deformation, and therefore the W-PTFE-Al composites exhibit excellent insensitivity and safety. Furthermore, the reaction mechanisms of W-PTFE-Al composites in argon and in air are revealed.
Mechanical behavior of carbon nanotube and graphene junction as a building block for 3D carbon nanostructures
Authors: Moradi Mina , Aghazadeh Mohandesi Jamshid
Published: November 2015

The incorporation of defects in junction area of 1D and 2D carbon nanostructures has a major impact on properties of their 3D structures. In the present study, molecular dynamics simulation is utilized to examine the mechanical behavior of graphene sheet (GS) in carbon nanotube (CNT)-GS junctions. The tensile load was applied along the GS in connection with CNTs of different chiralities. The adaptive intermolecular reactive empirical bond order potential was chosen to model C-C interactions. It provided a reliable model for CNT, GS and their junctions. The results revealed that the connection of CNT to the GS with a hole could improve the mechanical properties of defective GS, which appeared to be independent of CNT type. It was found that the high strength C-C bonds postpone the crack propagation and motivates new crack nucleation. When a hole or CNT placed on the GS, it caused stress concentration, exactly along a line on its side. The lower mechanical properties were consequently associated with crack nucleation and propagation on both sides in a way that cracks encountered each other during the failure; while, the cracks in pristine GS propagate parallel to each other and could not encounter each other.
Shoot–root carbon allocation, sugar signalling and their coupling with nitrogen uptake and assimilation
Authors: Wang Lu , Ruan Yong-Ling
Published: November 2015

Roots and shoots are distantly located but functionally interdependent. The growth and development of these two organ systems compete for energy and nutrient resource, and yet, they keep a dynamic balance with each other for growth and development. The success of such a relationship depends on efficient root-shoot communication. Aside from the well-known signalling processes mediated by hormones such as auxin and cytokinin, sugars have recently been shown to act as a rapid signal to co-ordinate root and shoot development in response to endogenous and exogenous clues, in parallel to their function as carbon and energy resources for biomass production. New findings from studies on vascular fluids have provided molecular insights into the role of sugars in long-distance communications between shoot and root. In this review, we discussed phloem- and xylem- translocation of sugars and the impacts of sugar allocation and signalling on balancing root–shoot development. Also, we have taken the shoot–root carbon–nitrogen allocation as an example to illustrate the communication between the two organs through multi-layer root–shoot–root signalling circuits, comprising sugar, nitrogen, cytokinin, auxin and vascular small peptide signals.
The eyes are the window to the uncanny valley
Authors: Schein Chelsea , Gray Kurt
Published: November 2015

Horror movies have discovered an easy recipe for making people creepy: alter their eyes. Instead of normal eyes, zombies’ eyes are vacantly white, vampires’ eyes glow with the color of blood, and those possessed by demons are cavernously black. In the Academy Award winning Pan’s Labyrinth, director Guillermo del Toro created the creepiest of all creatures by entirely removing its eyes from its face, placing them instead in the palms of its hands. The unease induced by altering eyes may help to explain the uncanny valley, which is the eeriness of robots that are almost—but not quite—human (Mori, 1970). Much research has explored the uncanny valley, including the research reported by MacDorman & Entezari (in press), which focuses on individual differences that might predict the eeriness of humanlike robots. In their paper, they suggest that a full understanding of this phenomenon needs to synthesize individual differences with features of the robot. One theory that links these two concepts is mind perception, which past research highlights as essential to the uncanny valley (Gray & Wegner, 2012). Mind perception is linked to both individual differences—autism—and to features of the robot—the eyes—and can provide a deeper understanding of this arresting phenomenon. In this paper, we present original data that links uncanniness to the eyes through aberrant perceptions of mind.
Experimental Infections of Bluegill with the Trematode Ribeiroia ondatrae (Digenea: Cathaemasiidae): Histopathology and Hematological Response
Authors: Calhoun Dana M. , Schaffer Paula A. , Gregory Jacklyn R. , Hardy Katherine M. , Johnson Pieter T. J.
Published: November 2015

Infections by the digenetic trematode, Ribeiroia ondatrae, cause severe limb malformations in many North American amphibians. Ribeiroia ondatrae also infects fishes as second intermediate hosts, but less is known about the pathology and immune responses initiated in infected fish, even though reports of infected fish date back to early 1900s. To this end, we experimentally exposed juvenile Bluegills Lepomis macrochirus to three doses of R. ondatrae cercariae and monitored the pathology, parasite infection success, and humoral responses over 648 h. All exposed fish became infected with metacercariae, and the average infection load increased with exposure dose. Histologically, infection was associated with acute hemorrhages in the lateral line and local dermis at 36 h, followed by progressive granulomatous inflammation that led to the destruction of encysted metacercariae. Correspondingly, over the course of 648 h we observed an 85% decline in average infection load among hosts, reflecting the host's clearance of the parasite. Infection was not associated with changes in fish growth or survival, but did correlate with leukocytosis and neutrophilia in circulating host blood. Understanding the physiological responses of R. ondatrae in Bluegill will help to clarify the ecological effects of this parasite and provide a foundation for subsequent comparisons into its effects on behavior, individual health, and population dynamics of Bluegill.

Received March 4, 2015; accepted August 9, 2015
Pharmacological modulation of neuropathic pain-related depression of behavior: effects of morphine, ketoprofen, bupropion and ∆9-tetrahydrocannabinol on formalin-induced depression of intracranial self-stimulation in rats
Authors: Leitl Michael D. , Negus S. Stevens
Published: November 2015

Neuropathic pain is often associated with behavioral depression. Intraplantar formalin produces sustained, neuropathy-associated depression of intracranial self-stimulation (ICSS) in rats. This study evaluated pharmacological modulation of formalin-induced ICSS depression. Rats with intracranial electrodes targeting the medial forebrain bundle responded for electrical brain stimulation in an ICSS procedure. Bilateral intraplantar formalin administration depressed ICSS for 14 days. Morphine (0.32–3.2 mg/kg), ketoprofen (0.1–10 mg/kg), bupropion (3.2–32 mg/kg), and ∆9-tetrahydrocannabinol (THC; 0.32–3.2 mg/kg) were evaluated for their effectiveness to reverse formalin-induced depression of ICSS. Drug effects on formalin-induced mechanical allodynia were evaluated for comparison. Morphine and bupropion reversed both formalin-induced ICSS depression and mechanical allodynia, and effects on ICSS were sustained during repeated treatment. Ketoprofen failed to reverse either formalin effect. THC blocked mechanical allodynia, but decreased ICSS in control rats and exacerbated formalin-induced depression of ICSS. The failure of ketoprofen to alter formalin effects suggests that formalin effects result from neuropathy rather than inflammation. The effectiveness of morphine and bupropion to reverse formalin effects agrees with other evidence that these drugs block pain-depressed behavior in rats and relieve neuropathic pain in humans. The effects of THC suggest general behavioral suppression and do not support the use of THC to treat neuropathic pain.
The relationship between the external environment and physician e-mail communication
Authors: Mazurenko Olena , Hearld Larry R. , Menachemi Nir
Published: November 2015

Background:

Physician e-mail communication, with patients and other providers, is one of the cornerstones of effective care coordination but varies significantly across physicians. A physician’s external environment may contribute to such variations by enabling or constraining a physician’s ability to adopt innovations such as health information technology (HIT) that can be used to support e-mail communication.

Purpose:

The aim of the study was to examine whether the relationship of the external environment and physician e-mail communication with patients and other providers is mediated by the practice’s HIT availability.

Methodology:

The data were obtained from the Health Tracking Physician Survey (2008) and the Area Resource File (2008). Cross-sectional multivariable subgroup path analysis was used to investigate the mediating role of HIT availability across 2,850 U.S. physicians.

Findings:

Solo physicians’ perceptions about malpractice were associated with 0.97 lower odds (p < .05) of e-mail communication with patients and other providers, as compared to group and hospital practices, even when mediated by HIT availability. Subgroup analyses indicated that different types of practices are responsive to the different dimensions of the external environment. Specifically, solo practitioners were more responsive to the availability of resources in their environment, with per capita income associated with lower likelihood of physician e-mail communication (OR = 0.99, p < .01). In contrast, physicians working in the group practices were more responsive to the complexity of their environment, with a physician’s perception of practicing in environments with higher malpractice risks associated with greater information technology availability, which in turn was associated with a greater likelihood of communicating via e-mail with patients (OR = 1.02, p < .05) and other physicians (OR = 1.03, p < .001).

Practical Applications:

The association between physician e-mail communication and the external environment is mediated by the practice’s HIT availability. Efforts to improve physician e-mail communication and HIT adoption may need to reflect the varied perceptions of different types of practices.
Organizational capacity for change in health care
Authors: Spaulding Aaron , Kash Bita A. , Johnson Christopher E. , Gamm Larry
Published: November 2015

Background:

We do not have a strong understanding of a health care organization’s capacity for attempting and completing multiple and sometimes competing change initiatives. Capacity for change implementation is a critical success factor as the health care industry is faced with ongoing demands for change and transformation because of technological advances, market forces, and regulatory environment.

Purpose:

The aim of this study was to develop and validate a tool to measure health care organizations’ capacity to change by building upon previous conceptualizations of absorptive capacity and organizational readiness for change.

Methodology/Approach:

A multistep process was used to develop the organizational capacity for change survey. The survey was sent to two populations requesting answers to questions about the organization’s leadership, culture, and technologies in use throughout the organization. Exploratory and confirmatory factor analyses were conducted to validate the survey as a measurement tool for organizational capacity for change in the health care setting.

Findings:

The resulting organizational capacity for change measurement tool proves to be a valid and reliable method of evaluating a hospital’s capacity for change through the measurement of the population’s perceptions related to leadership, culture, and organizational technologies.

Practical Implications:

The organizational capacity for change measurement tool can help health care managers and leaders evaluate the capacity of employees, departments, and teams for change before large-scale implementation.
Microbiology and Biofilm Trends of Silicone Lacrimal Implants: Comparing Infected Versus Routinely Removed Stents
Authors: Samimi David B. , Ediriwickrema Lilangi S. , Bielory Brett P. , Miller Darlene , Lee Wendy , Johnson Thomas E.
Published: November 2015

Purpose:

To investigate the pathogens and biofilms responsible for clinically significant infection of silicone stents implanted within the lacrimal system.

Methods:

Retrospective review of culture results and patient demographics for all silicone lacrimal stents removed early for clinically significant infection and sent to the Bascom Palmer Microbiology Laboratory through the end of year 2010. As a control, routinely removed, clinically noninfected stents from the same institution were prospectively sent for culture over a 6-month period. Four clinically infected and 6 clinically noninfected stents showing mucus within the lumen at removal were sent for scanning electron microscopy. Images were randomized and graded by a microbiologist for the presence of organisms, matrix deposits, organisms within matrix, and overall impression of significant biofilm formation.

Results:

Nineteen stents were included in the study; 100% of clinically infected (n = 10) and noninfected (n = 9) stents were culture positive. Culture positivity for nontuberculous mycobacterium was found in 90% of infected stents and none of the noninfected stents (p < 0.001). Of infected stents, 50% grew Gram-positive organisms compared with 89% of noninfected stents (p = 0.07). Fifty percent of infected versus 67% of noninfected stents were culture positive for Gram-negative organisms (p = 0.46). Electron microscopy of stents revealed organisms consistent with culture results (size, shape) in planktonic and biofilm form. Masked observer image grading revealed a statistically significant higher amount of organism and biofilm on infected versus noninfected specimen.

Conclusion:

Nontuberculous mycobacteria comprise the primary pathogens responsible for clinically significant infection of silicone stents in the lacrimal system in South Florida. Robust biofilm production by this organism likely plays a role in pathogenesis. Further research into biofilm-related lacrimal implant infection may aid in the development of useful prevention and treatment strategies.
Simultaneous Versus Staged Balanced Decompression for Thyroid-Related Compressive Optic Neuropathy
Authors: Wu Chris Y. , Stacey Andrew W. , Kahana Alon
Published: November 2015

Purpose:

To compare the visual and exophthalmometry outcomes of simultaneous versus staged balanced decompression in patients with thyroid-related compressive optic neuropathy (CON).

Methods:

All consecutive patients who underwent simultaneous or staged balanced decompressions for clinically diagnosed thyroid-related CON performed by 4 surgeons at the Kellogg Eye Center of the University of Michigan between 1999 and 2014 were included in the study. Demographic, medical, and surgical covariates were collected. Orbits were stratified by decompression technique. Primary outcomes were improvement in CON score (which quantifies visual dysfunction using logarithm of the minimum angle of resolution, color vision, and Humphrey visual field mean deviation), and improvement in proptosis. The authors performed univariate and descriptive statistics to identify baseline differences and covariates associated with the outcomes of interest; multivariate mixed linear regression models (to adjust for interorbit correlation) were then constructed with inclusion of potential confounders with p value ≤0.1.

Results:

In total, 80 orbits of 53 patients were included in the study. Of the 80 orbits, 61% underwent simultaneous balanced decompression, and 39% underwent staged balanced decompression. Mean CON score reduction was 6.12 ± 9.7 and mean proptosis reduction was 5.63 ± 2.6 mm. Staged balanced decompression was significantly associated with greater CON score reduction (p = 0.038). However, staged (vs. simultaneous) decompression technique did not remain an independent predictor (p = 0.950) after multivariate analysis adjusted for confounders. For proptosis reduction, there were no statistically significant differences between simultaneous and staged balanced decompression on univariate (p = 0.122) or multivariate mixed linear regression models (p = 0.812).

Conclusion:

Simultaneous and staged balanced decompression are equally efficacious in treating visual dysfunction and exophthalmos due to thyroid eye disease in patients with clinically diagnosed CON. Patient choice should be the primary consideration and care should be individualized. Further studies validating the CON score used in the study and comparative studies individualizing surgical treatment of thyroid eye disease are warranted.
Adverse Events Following Gastrointestinal Endoscopy in Children
Authors: Kramer Robert E. , Narkewicz Michael R.
Published: November 2015

Objective:

To conduct a comprehensive study of postendoscopic adverse events (AEs) in children, categorizing them by the level of intervention required.

Background:

Previous studies of endoscopic AE in children have focused on intraprocedural and short‐term outcomes, such as bleeding, perforation, and infection, and may underestimate the incidence of AEs.

Design:

Prospective observational study tracking AEs in pediatric patients within 72 hours of an endoscopic procedure.

Setting:

Single‐center study performed at an academic, tertiary care, free‐standing children's hospital over a 48‐month period, from July 2010 through June 2014.

Patients and Interventions:

Of 9577 pediatric endoscopic procedures, cases identified as having an AE during or following endoscopy were subject to additional chart review for abstraction of relevant data.

Main Outcome Measurements:

Type, severity, and subsequent interventions of AEs were the primary outcome measures. Events were categorized by severity grade, with grade 1, no intervention; grade 2, outpatient evaluation; grade 3, hospitalization or repeat endoscopy; grade 4, surgery or intensive care unit admission; and grade 5, death.

Results:

In total, 249 endoscopic AEs were recognized of 9577 procedures performed, yielding a rate of 2.6%. Of these, 160 were identified to result in medical evaluation and costs (≥grade 2) for a rate of 1.7%. Rates of endoscopic AE after advanced or interventional endoscopic procedures were higher, with 65 of 1167 events, resulting in a total AE rate of 5.6% and a rate of 4.4% for AE ≥ grade 2. There were 10 cases of significant bleeding (0.1%), 9 cases of infection (0.09%), and 12 cases of perforation (0.13%), primarily occurring with advanced/interventional procedures.

Limitations:

Single‐center study, lack of standardized criteria for ED referral.

Conclusions:

AEs presenting within 72 hours of endoscopy and resulting in medical intervention, occur more commonly than previously recognized in children. Standardized postendoscopy surveillance systems and definitions of AEs are needed.
ACR Appropriateness Criteria® Acute Pelvic Pain in the Reproductive Age Group
Authors: Bhosale Priyadarshani R. , Javitt Marcia C. , Atri Mostafa , Harris Robert D. , Kang Stella K. , Meyer Benjamin J. , Pandharipande Pari V. , Reinhold Caroline , Salazar Gloria M. , Shipp Thomas D. , Simpson Lynn , Sussman Betsy L. , Uyeda Jennifer , Wall Darci J. , Zelop Carolyn M. , Glanc Phyllis
Published: November 2015

Acute pelvic pain in premenopausal women frequently poses a diagnostic dilemma. These patients may exhibit nonspecific signs and symptoms such as nausea, vomiting and leukocytosis. The cause of pelvic pain includes a myriad of diagnostic possibilities such as obstetric, gynecologic, urologic, gastrointestinal, and vascular etiologies. The choice of the imaging modality is usually determined by a suspected clinical differential diagnosis. Thus the patient should undergo careful evaluation and the suspected differential diagnosis should be narrowed before an optimal imaging modality is chosen. Transvaginal and transabdominal pelvic sonography is the modality of choice, to assess for pelvic pain, when an obstetric or gynecologic etiology is suspected and computed tomography is often more useful when gastrointestinal or genitourinary pathology is thought to be more likely. Magnetic resonance imaging, when available in the acute setting, is favored over computed tomography for assessing pregnant patients for nongynecologic etiologies owing to its lack of ionizing radiation.

The American College of Radiology Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions that are reviewed every three years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.
From raw reads to trees: Whole genome SNP phylogenetics across the tree of life
Authors: Ahmed Sanaa A. , Lo Chien-Chi , Li Po-E , Davenport Karen W. , Chain Patrick S. G.
Published: November 2015

Next-generation sequencing is increasingly being used to examine closely related organisms. However, while genome-wide single nucleotide polymorphisms (SNPs) provide an excellent resource for phylogenetic reconstruction, to date evolutionary analyses have been performed using different ad hoc methods that are not often widely applicable across different projects. To facilitate the construction of robust phylogenies, we have developed a method for genome-wide identification/characterization of SNPs from sequencing reads and genome assemblies. Our phylogenetic and molecular evolutionary (PhaME) analysis software is unique in its ability to take reads and draft/complete genome(s) as input, derive core genome alignments, identify SNPs, construct phylogenies and perform evolutionary analyses. Several examples using genomes and read datasets for bacterial, eukaryotic and viral linages demonstrate the broad and robust functionality of PhaME. Furthermore, the ability to incorporate raw metagenomic reads from clinical samples with suspected infectious agents shows promise for the rapid phylogenetic characterization of pathogens within complex samples.
Down-regulation of LATS kinases alters p53 to promote cell migration
Authors: Furth Noa , Bossel Ben-Moshe Noa , Pozniak Yair , Porat Ziv , Geiger Tamar , Domany Eytan , Aylon Yael , Oren Moshe
Published: November 2015

p53 is a pivotal tumor suppressor and a major barrier against cancer. We now report that silencing of the Hippo pathway tumor suppressors LATS1 and LATS2 in nontransformed mammary epithelial cells reduces p53 phosphorylation and increases its association with the p52 NF-κB subunit. Moreover, it partly shifts p53's conformation and transcriptional output toward a state resembling cancer-associated p53 mutants and endows p53 with the ability to promote cell migration. Notably, LATS1 and LATS2 are frequently down-regulated in breast cancer; we propose that such down-regulation might benefit cancer by converting p53 from a tumor suppressor into a tumor facilitator.