bluuebunny/crossref_metadata_2025 huggingface dataset:
Locally non‐uniform oxidation in self‐terminating thermal oxidation assisted wet etching technique for AlGaN/GaN heterostructure
Authors: Liu Jingqian , Wang Jinyan , Xu Zhe , Jiang Haisang , Yang Zhenchuan , Wang Maojun , Yu Min , Xie Bing , Wu Wengang , Ma Xiaohua , Zhang Jincheng , Hao Yue
Published: October 2015

The oxidation mechanism in self‐terminating wet etching technique with thermal oxidation of AlGaN layer followed by etching in KOH solution is investigated. Spike‐shape remnants of oxidised AlGaN are observed at the initial stage of wet etching in KOH solution, which could be completely etched away after enough etching time. Transmission electron microscope/energy dispersive spectroscopy analysis indicates the existence of crystalline AlGaN inside the remnants. Finally, a possible explanation is given that the oxide channels from AlGaN surface towards AlGaN/GaN interface generated during thermal oxidation are firstly etched away at the initial stage of KOH wet etching, then after enough time these remnants with non‐c axis crystal orientation surfaces exposed to KOH solution could be completely etched away leaving GaN layer beneath unaffected, which realises self‐terminating etching.
Built‐in parasitic‐diode‐based charge injection technique enhancing data retention of gain cell DRAM
Authors: Chung Yeonbae , Cheng Weijie , Das Hritom
Published: October 2015

A gain cell embedded dynamic random access memory (eDRAM) with a noble charge injection technique is presented. The gain memory cell is composed of dual‐threshold two logic N‐type MOSs implemented in a generic triple‐well CMOS process. A negative‐voltage toggle on the parasitic junction diode formed between the pocket p‐well and the cell data node couples up the cell storage voltages. It results in a much enhanced retention time in a compact bit area. Moreover, the technique exhibits much strong immunity from the write disturbance. Measured results at 85°C from a 110 nm 64 kbit prototype eDRAM incorporating the proposed technique demonstrate 69% enhanced retention time and 86% smaller write disturbance loss compared with the conventional one.
Enhanced locking range technique for frequency divider using dual‐resonance RLC resonator
Authors: Jang S.‐L. , Chen Y.‐J. , Fang C.‐H. , Lai W.C.
Published: October 2015

An enhanced locking range technique for a CMOS injection‐locked frequency divider (ILFD) is presented, which uses a cross‐coupled oscillator with a dual‐resonance RLC resonator. This ILFD has dual locking ranges at a fixed bias, and the resistor in the resonator is used to have overlapping dual locking ranges so that a single‐band wide‐locking range is obtained. At the incident power of 0 dBm, the locking range of the divide‐by‐2 ILFD is 6.7 GHz, from 3 to 9.7 GHz, and the locking range percentage is 105.51%.
RC‐loaded planar half‐ellipse antenna for impulse radar application
Authors: Wang Youcheng , Fang Guangyou , Zhang Feng , Ji Yicai , Zhang Xiaojuan
Published: October 2015

Combined with the resistor loading and capacitive loading technique, a planar printed ellipse antenna is designed to achieve ultra‐bandwidth and upper radiation efficiency. To accomplish loading, four resistor lumps bridge the metallic strip against the antenna arm on the top layer and rectangular conducting cavity. Simulations are performed for various characteristics of the antenna such as current distribution, near‐field radiation pattern and time waveform. Comparison of antenna characteristics between the antenna with resistor loading (type‐I) and the antenna with resistor and capacitive loading (type‐II) is made using simulations and measurements. The proposed antenna is constructed and measured. It is shown that the antenna achieves an ultra‐bandwidth over 8:1 (1–8 GHz) with a return loss less than −10 dB. In addition, experimental verification has been carried out to confirm the improved properties of the antenna. The capacitive loading produced at the end of the antenna arm has improved the peak of the radiation waveform at least 0.62 dB without the cost of increased size.
Review of AC power theories under stationary and non‐stationary, clean and distorted conditions
Authors: Kukačka Leoš , Kraus Jan , Kolář Milan , Dupuis Pascal , Zissis Georges
Published: October 2015

This study is a review of traditional and non‐traditional electric power theories. Along with the standard IEEE 1459‐2010, other definitions like the currents’ physical components theory, p–q, p–q–r theories are briefly described with the accent on analysis of a priori unknown electric systems. The mathematical definitions were implemented and tested on real measured data, which facilitates the uncovering of some advantages and disadvantages. In the conclusion some of the pros and cons of the undermentioned theories are discussed.
Transition control of Mach to regular reflection induced interaction using an array of micro ramp vane-type vortex generators
Authors: Verma Shashi B. , Chidambaranathan Manisankar
Published: October 2015

An experimental investigation has been conducted to favorably control/modify a Mach reflection induced interaction in a Mach 2.05 flow on a flat plate using an array of single row mechanical micro vane-type vortex generators (VGs). The objective was to study the variation in (i) control device configuration (trapezoidal and the split-trapezoidal or ramp vane-type), (ii) control device height (h/δ = 0.3, 0.5), and (iii) control location (X/δ = 9, 15 upstream of the interaction) in controlling the overall interaction. The primary aim was to investigate a control location and VG configuration which is able to effectively initiate a transition from Mach reflection to regular reflection with minimum changes to the separation characteristics for no control. While the trapezoidal configuration is seen to move the separation location upstream only slightly, the split-trapezoidal configurations result in a considerable upstream movement that is associated with significant reduction in separation shock strength. The latter flow modification causes the Mach stem to completely disappear resulting in a transition from Mach to regular reflection. The control location of X/δ = 15 seems to be most effective for all control device configurations tested. It is further observed that whilst the effectiveness of the split-trapezoidal configuration of h/δ = 0.3 in controlling the transition improves with increasing X/δ, increasing its height to h/δ = 0.5 not only controls the transition process but is also able to control the extent of separation. All the control devices, however, are seen to increase the flow unsteadiness in the intermittent region of separation for both control locations. From this perspective, increasing the height of the control device seems favorable for the closer control location as it not only completely modifies the Mach reflection but also keeps the peak rms value similar to the baseline case.
Exchangeable, stationary, and entangled chains of Gaussian states
Authors: Parthasarathy K. R. , Sengupta Ritabrata
Published: October 2015

We explore conditions on the covariance matrices of a consistent chain of mean zero finite mode Gaussian states in order that the chain may be exchangeable or stationary. For an exchangeable chain, our conditions are necessary and sufficient. Every stationary Gaussian chain admits an asymptotic entropy rate. Whereas an exchangeable chain admits a simple expression for its entropy rate, in our examples of stationary chains, the same admits an integral formula based on the asymptotic eigenvalue distribution for Toeplitz matrices. An example of a stationary entangled Gaussian chain is given.
Synchronized vortex shedding and sound radiation from two side-by-side rectangular cylinders of different cross-sectional aspect ratios
Authors: Octavianty Ressa , Asai Masahito
Published: October 2015

Synchronized vortex shedding from two side-by-side cylinders and the associated sound radiation were examined experimentally at Reynolds numbers of the order of 104 in low-Mach-number flows. In addition to a pair of square cylinders, a pair of rectangular cylinders, one with a square cross section (d × d) and the other with a rectangular cross section (d × c) having a cross-sectional aspect ratio (c/d) of 1.2–1.5, was considered. The center-to-center distance between the two cylinders L/d was 3.6, 4.5, and 6.0; these settings were within the non-biased flow regime for side-by-side square cylinders. In case of a square cylinder pair, anti-phase synchronized vortex shedding occurring for L/d = 3.6 and 4.5 generated a quadrupole-like sound source which radiated in-phase, planar-symmetric sound in the far field. Synchronized vortex shedding from the two rectangular cylinders with different c/d also occurred with almost the same frequency as the characteristic frequency of the square-cylinder wake in the case of the small center-to-center distance, L/d = 3.6, for all the cylinder pairs examined. The synchronized sound field was anti-phase and asymmetric in amplitude, unlike the case of a square cylinder pair. For larger spacing L/d = 4.5, synchronized vortex shedding and anti-phase sound still occurred, but only for close cross-sectional aspect ratios (c/d = 1.0 and 1.2), and highly modulated sound was radiated with two different frequencies due to non-synchronized vortex shedding from the two cylinders for larger differences in c/d. It was also found that when synchronized vortex shedding occurred, near-wake velocity fluctuations exhibited high spanwise-coherency, with a very sharp spectral peak compared with the single-cylinder case.
An integrated microfluidic system for screening of phage-displayed peptides specific to colon cancer cells and colon cancer stem cells
Authors: Che Yu-Jui , Wu Huei-Wen , Hung Lien-Yu , Liu Ching-Ann , Chang Hwan-You , Wang Kuan , Lee Gwo-Bin
Published: October 2015

Affinity reagents recognizing biomarkers specifically are essential components of clinical diagnostics and target therapeutics. However, conventional methods for screening of these reagents often have drawbacks such as large reagent consumption, the labor-intensive or time-consuming procedures, and the involvement of bulky or expensive equipment. Alternatively, microfluidic platforms could potentially automate the screening process within a shorter period of time and reduce reagent and sample consumption dramatically. It has been demonstrated recently that a subpopulation of tumor cells known as cancer stem cells possess high drug resistance and proliferation potential and are regarded as the main cause of metastasis. Therefore, a peptide that recognizes cancer stem cells and differentiates them from other cancer cells will be extremely useful in early diagnosis and target therapy. This study utilized M13 phage display technology to identify peptides that bind, respectively, to colon cancer cells and colon cancer stem cells using an integrated microfluidic system. In addition to positive selection, a negative selection process was integrated on the chip to achieve the selection of peptides of high affinity and specificity. We successfully screened three peptides specific to colon cancer cells and colon cancer stem cells, namely, HOLC-1, HOLC-2, and COLC-1, respectively, and their specificity was measured by the capture rate between target, control, and other cell lines. The capture rates are 43.40 ± 7.23%, 45.16 ± 7.12%, and 49.79 ± 5.34% for colon cancer cells and colon cancer stem cells, respectively, showing a higher specificity on target cells than on control and other cell lines. The developed technique may be promising for early diagnosis of cancer cells and target therapeutics.
An advanced negative hydrogen ion source
Authors: Goncharov Alexey A. , Dobrovolsky Andrey N. , Goretskii Victor P.
Published: October 2015

The results of investigation of emission productivity of negative particles source with cesiated combined discharge are presented. A cylindrical beam of negative hydrogen ions with density about 2 A/cm2 in low noise mode on source emission aperture is obtained. The total beam current values are up to 200 mA for negative hydrogen ions and up to 1.5 A for all negative particles with high divergence after source. The source has simple design and can produce stable discharge with low level of oscillation.
Transition metal contacts to graphene
Authors: Politou Maria , Asselberghs Inge , Radu Iuliana , Conard Thierry , Richard Olivier , Lee Chang Seung , Martens Koen , Sayan Safak , Huyghebaert Cedric , Tokei Zsolt , De Gendt Stefan , Heyns Marc
Published: October 2015

Achieving low resistance contacts to graphene is a common concern for graphene device performance and hybrid graphene/metal interconnects. In this work, we have used the circular Transfer Length Method (cTLM) to electrically characterize Ag, Au, Ni, Ti, and Pd as contact metals to graphene. The consistency of the obtained results was verified with the characterization of up to 72 cTLM structures per metal. Within our study, the noble metals Au, Ag and Pd, which form a weaker bond with graphene, are shown to result in lower contact resistance (Rc) values compared to the more reactive Ni and Ti. X-ray Photo Electron Spectroscopy and Transmission Electron Microscopy characterization for the latter have shown the formation of Ti and Ni carbides. Graphene/Pd contacts show a distinct intermediate behavior. The weak carbide formation signature and the low Rc values measured agree with theoretical predictions of an intermediate state of weak chemisorption of Pd on graphene.
On the nature of the molecular ordering of water in aqueous DMSO mixtures
Authors: Perera Aurélien , Mazighi Redha
Published: October 2015

Computer simulation studies of aqueous dimethyl sulfoxyde (DMSO) mixtures show micro-heterogeneous structures, just like aqueous alcohol mixtures. However, there is a marked difference in the aggregate structure of water between the two types of systems. While water molecules form multiconnected globular clusters in alcohols, we report herein that the typical water aggregates in aqueous DMSO mixtures are linear, favouring a 2 hydrogen bond structure per water molecule, and for all DMSO mole fractions ranging from 0.1 to 0.9. This linear-aggregate structure produces a particular signature in the water site-site structure factors, in the form of a pre-peak at k ≈ 0.2–0.8 Å−1, depending on DMSO concentration. This pre-peak is either absent in other aqueous mixtures, such as aqueous methanol mixtures, or very difficult to see through computer simulations, such as in aqueous-t-butanol mixtures. This difference in the topology of the aggregates explains why the Kirkwood-Buff integrals of aqueous-DMSO mixture look nearly ideal, in contrast with those of aqueous alcohol mixtures, suggesting a connection between the shape of the water aggregates, its fluctuations, and the concentration fluctuations. In order to further study this discrepancy between aqueous DMSO and aqueous alcohol mixture, two models of pseudo-DMSO are introduced, where the size of the sulfur atom is increased by a factor 1.6 and 1.7, respectively, hence increasing the hydrophobicity of the molecule. The study shows that these mixtures become closer to the emulsion type seen in aqueous alcohol mixtures, with more globular clustering of the water molecules, long range domain oscillations in the water-water correlations and increased water-water Kirkwood-Buff integrals. It demonstrates that the local ordering of the water molecules is influenced by the nature of the solute molecules, with very different consequences for structural properties and related thermodynamic quantities. This study illustrates the unique plasticity of water in presence of different types of solutes.
A synthetic approach for enhanced thermoelectric properties of PEDOT:PSS bulk composites
Authors: Wei Kaya , Stedman Troy , Ge Zhen-Hua , Woods Lilia M. , Nolas George S.
Published: October 2015

The thermoelectric properties of PEDOT:PSS/Bi0.5Sb1.5Te3 polymer/inorganic bulk composites with different Bi0.5Sb1.5Te3 content were investigated. The composites were prepared at various concentrations of Bi0.5Sb1.5Te3 by a solution-phase process before grinding to fine powders in liquid N2 for hot pressing into bulk polymer composite materials. The measured transport properties are well described within a theoretical model for effective media involving a tunneling mechanism induced by thermal voltage fluctuations. Our results present a strategy for the preparation of bulk polymer composites and demonstrate an avenue for optimization of the thermoelectric properties of PEDOT:PSS/Bi0.5Sb1.5Te3 bulk composites.
Enhanced optical nonlinearities in the near-infrared using III-nitride heterostructures coupled to metamaterials
Authors: Wolf Omri , Allerman Andrew A. , Ma Xuedan , Wendt Joel R. , Song Alex Y. , Shaner Eric A. , Brener Igal
Published: October 2015

We use planar metamaterial resonators to enhance by more than two orders of magnitude the near infrared second harmonic generation obtained from intersubband transitions in III-Nitride heterostructures. The improvement arises from two factors: employing an asymmetric double quantum well design and aligning the resonators' cross-polarized resonances with the intersubband transition energies. The resulting nonlinear metamaterial operates at wavelengths where single photon detection is available, and represents a different class of sources for quantum photonics related phenomena.
All-optical photoacoustic microscopy based on plasmonic detection of broadband ultrasound
Authors: Wang Tianxiong , Cao Rui , Ning Bo , Dixon Adam J. , Hossack John A. , Klibanov Alexander L. , Zhou Qifa , Wang Anbo , Hu Song
Published: October 2015

We report on an implementation of all-optical photoacoustic microscopy (PAM), which capitalizes on the effect of surface plasmon resonance (SPR) for optical detection of ultrasound. The SPR sensor in our all-optical PAM shows, experimentally, a linear response to the acoustic pressure from 5.2 kPa to 2.1 MPa, an ultra-flat frequency response (±0.7 dB) from 680 kHz to 126 MHz, and a noise-equivalent pressure sensitivity of 3.3 kPa. With the broadband ultrasonic detection, our SPR-PAM has achieved high spatial resolution with relatively low anisotropy (i.e., 2.0 μm laterally and 8.4 μm axially). Three-dimensional high-resolution imaging of a single melanoma cell is demonstrated.
1300 nm optically pumped quantum dot spin vertical external-cavity surface-emitting laser
Authors: Alharthi S. S. , Orchard J. , Clarke E. , Henning I. D. , Adams M. J.
Published: October 2015

We report a room temperature optically pumped Quantum Dot-based Spin-Vertical-External-Cavity Surface-Emitting laser (QD Spin-VECSEL) operating at the telecom wavelength of 1.3 μm. The active medium was composed of 5 × 3 QD layers; each threefold group was positioned at an antinode of the standing wave of the optical field. Circularly polarized lasing in the QD-VECSEL under Continuous-Wave optical pumping has been realized with a threshold pump power of 11 mW. We further demonstrate at room temperature control of the QD-VECSEL output polarization ellipticity via the pump polarization.
Scattering attributes of one-dimensional semiconducting oxide nanomaterials individually probed for varying light-matter interaction angles
Authors: Choi Daniel S. , Singh Manpreet , Zhou Hebing , Milchak Marissa , Hahm Jong-in
Published: October 2015

We report the characteristic optical responses of one-dimensional semiconducting oxide nanomaterials by examining the individual nanorods (NRs) of ZnO, SnO2, indium tin oxide, and zinc tin oxide under precisely controlled, light-matter interaction geometry. Scattering signals from a large set of NRs of the different types are evaluated spatially along the NR length while varying the NR tilt angle, incident light polarization, and analyzer rotation. Subsequently, we identify material-indiscriminate, NR tilt angle- and incident polarization-dependent scattering behaviors exhibiting continuous, intermittent, and discrete responses. The insight gained from this study can advance our fundamental understanding of the optical behaviors of the technologically useful nanomaterials and, at the same time, promote the development of highly miniaturized, photonic and bio-optical devices utilizing the spatially controllable, optical responses of the individual semiconducting oxide NRs.
Optimization of conditions for growth of vanadium dioxide thin films on silicon by pulsed-laser deposition
Authors: Shibuya Keisuke , Sawa Akihito
Published: October 2015

We systematically examined the effects of the substrate temperature (TS) and the oxygen pressure (PO2) on the structural and optical properties polycrystalline V O2 films grown directly on Si(100) substrates by pulsed-laser deposition. A rutile-type V O2 phase was formed at a TS ≥ 450 °C at PO2 values ranging from 5 to 20 mTorr, whereas other structures of vanadium oxides were stabilized at lower temperatures or higher oxygen pressures. The surface roughness of the V O2 films significantly increased at growth temperatures of 550 °C or more due to agglomeration of V O2 on the surface of the silicon substrate. An apparent change in the refractive index across the metal–insulator transition (MIT) temperature was observed in V O2 films grown at a TS of 450 °C or more. The difference in the refractive index at a wavelength of 1550 nm above and below the MIT temperature was influenced by both the TS and PO2, and was maximal for a V O2 film grown at 450 °C under 20 mTorr. Based on the results, we derived the PO2 versus 1/TS phase diagram for the films of vanadium oxides, which will provide a guide to optimizing the conditions for growth of V O2 films on silicon platforms.
Linguistic innovation, political centralization and economic integration in the Kongo kingdom
Authors: Bostoen Koen , de Schryver Gilles-Maurice
Published: October 2015

In this article we reconstruct the actuation and transmission of a phonological innovation known as prefix reduction within the Kikongo language cluster situated in the wider Lower Congo region of Central Africa. We argue that this change spread from a focal area coinciding with the heartland of the Kongo kingdom as a classical process of dialectal diffusion. Thanks to a unique Kikongo corpus that starts in the 17th century, we can provide diachronic empirical evidence for different phases of the process, which has been otherwise difficult, if not impossible, in Bantu historical linguistics. What is more, and also quite exceptional in African linguistics, we have fairly good insight into the ‘social ecology’ of this language change and argue that political centralization and economic integration within the realm of the Kongo kingdom facilitated such a contact-induced diffusion between closely-related language varieties.
First dust study in JET with the ITER-like wall: sampling, analysis and classification
Authors: Baron-Wiechec A. , Fortuna-Zaleśna E. , Grzonka J. , Rubel M. , Widdowson A. , Ayres C. , Coad J. P. , Hardie C. , Heinola K. , Matthews G. F.
Published: October 2015

Results of the first dust survey in JET with the ITER-Like Wall (JET-ILW) are presented. The sampling was performed using adhesive stickers from the divertor tiles where the greatest material deposition was detected after the first JET-ILW campaign in 2011–2012. The emphasis was especially on sampling and analysis of metal particles (Be and W) with the aim to determine the composition, size, surface topography and internal dust structure using a large set of methods: high-resolution scanning and transmission electron microscopy, focused ion beam, electron diffraction and also wavelength and energy dispersive x-ray spectroscopy. The most important was the identification of beryllium dust both in the form of flakes and droplets with dimensions in the micrometer range. Tungsten, molybdenum, inconel constituents were identified along with many impurity species. The particles are categorised and the origin of the various constituents discussed.
An open-structure electrowetting-based reflective display with a feedback system
Authors: Choi Seungyul , Lee Junghoon
Published: October 2015

Electrowetting-based reflective displays have long been considered a promising display choice for electronic paper applications due to their fast operating speeds and high color contrasts. However, they still require several improvements in terms of their packaging process, color contrast, and reliability. This study investigates such enhancements via an open-structure design and a capacitive feedback system. It has a femto-farad level resolution and demonstrates a high operating speed (approximately 10 ms), effective ink dosing, and large color area change (approximately 92%). The feedback system for the precise control of the color area is verified by testing under a wide range of interfacial tension. The system reduces the deviation of color contrast by 85%. Working with high fidelity with large disturbances, which are represented by interfacial variations, the system shows robust performance against other disturbances, such as temperature variation and contact angle hysteresis.
𝐿^{𝑝} estimates for a singular entangled quadrilinear form
Authors: Durcik Polona
Published: October 2015

We prove

L

p

\mathrm {L}^p

estimates for a continuous version of a dyadic quadrilinear form introduced by V. Kovač (2012). This improves the range of exponents from the prequel of the present paper.
Inhibition of the mitochondrial fission protein dynamin-related protein 1 (Drp1) impairs mitochondrial fission and mitotic catastrophe after x-irradiation
Authors: Yamamori Tohru , Ike Satoshi , Bo Tomoki , Sasagawa Tomoya , Sakai Yuri , Suzuki Motofumi , Yamamoto Kumiko , Nagane Masaki , Yasui Hironobu , Inanami Osamu
Published: October 2015

Accumulating evidence suggests that mitochondrial dynamics is crucial for the maintenance of cellular quality control and function in response to various stresses. However, the role of mitochondrial dynamics in cellular responses to ionizing radiation (IR) is still largely unknown. In this study, we provide evidence that IR triggers mitochondrial fission mediated by the mitochondrial fission protein dynamin-related protein 1 (Drp1). We also show IR-induced mitotic catastrophe (MC), which is a type of cell death associated with defective mitosis, and aberrant centrosome amplification in mouse embryonic fibroblasts (MEFs). These are attenuated by genetic or pharmacological inhibition of Drp1. Whereas radiation-induced aberrant centrosome amplification and MC are suppressed by the inhibition of Plk1 and CDK2 in wild-type MEFs, the inhibition of these kinases is ineffective in Drp1-deficient MEFs. Furthermore, the cyclin B1 level after irradiation is significantly higher throughout the time course in Drp1-deficient MEFs than in wild-type MEFs, implying that Drp1 is involved in the regulation of cyclin B1 level. These findings strongly suggest that Drp1 plays an important role in determining the fate of cells after irradiation via the regulation of mitochondrial dynamics.
CompartmentalizedToxoplasmaEB1 bundles spindle microtubules to secure accurate chromosome segregation
Authors: Chen Chun-Ti , Kelly Megan , Leon Jessica de , Nwagbara Belinda , Ebbert Patrick , Ferguson David J. P. , Lowery Laura Anne , Morrissette Naomi , Gubbels Marc-Jan
Published: October 2015

Toxoplasma gondii replicates asexually by a unique internal budding process characterized by interwoven closed mitosis and cytokinesis. Although it is known that the centrosome coordinates these processes, the spatiotemporal organization of mitosis remains poorly defined. Here we demonstrate that centrosome positioning around the nucleus may signal spindle assembly: spindle microtubules (MTs) are first assembled when the centrosome moves to the basal side and become extensively acetylated after the duplicated centrosomes reposition to the apical side. We also tracked the spindle MTs using the MT plus end–binding protein TgEB1. Endowed by a C-terminal NLS, TgEB1 resides in the nucleoplasm in interphase and associates with the spindle MTs during mitosis. TgEB1 also associates with the subpellicular MTs at the growing end of daughter buds toward the completion of karyokinesis. Depletion of TgEB1 results in escalated disintegration of kinetochore clustering. Furthermore, we show that TgEB1’s MT association in Toxoplasma and in a heterologous system ( Xenopus) is based on the same principles. Finally, overexpression of a high-MT-affinity TgEB1 mutant promotes the formation of overstabilized MT bundles, resulting in avulsion of otherwise tightly clustered kinetochores. Overall we conclude that centrosome position controls spindle activity and that TgEB1 is critical for mitotic integrity.
Phosphatidylserine translocation at the yeasttrans-Golgi network regulates protein sorting into exocytic vesicles
Authors: Hankins Hannah M. , Sere Yves Y. , Diab Nicholas S. , Menon Anant K. , Graham Todd R.
Published: October 2015

Sorting of plasma membrane proteins into exocytic vesicles at the yeast trans-Golgi network (TGN) is believed to be mediated by their coalescence with specific lipids, but how these membrane-remodeling events are regulated is poorly understood. Here we show that the ATP-dependent phospholipid flippase Drs2 is required for efficient segregation of cargo into exocytic vesicles. The plasma membrane proteins Pma1 and Can1 are missorted from the TGN to the vacuole in drs2∆ cells. We also used a combination of flippase mutants that either gain or lose the ability to flip phosphatidylserine (PS) to determine that PS flip by Drs2 is its critical function in this sorting event. The primary role of PS flip at the TGN appears to be to control the oxysterol-binding protein homologue Kes1/Osh4 and regulate ergosterol subcellular distribution. Deletion of KES1 suppresses plasma membrane–missorting defects and the accumulation of intracellular ergosterol in drs2 mutants. We propose that PS flip is part of a homeostatic mechanism that controls sterol loading and lateral segregation of protein and lipid domains at the TGN.
CARMIL2 is a novel molecular connection between vimentin and actin essential for cell migration and invadopodia formation
Authors: Lanier M. Hunter , Kim Taekyung , Cooper John A.
Published: October 2015

Cancer cell migration requires the regulation of actin networks at protrusions associated with invadopodia and other leading edges. Carcinomas become invasive after undergoing an epithelial–mesenchymal transition characterized by the appearance of vimentin filaments. While vimentin expression correlates with cell migration, the molecular connections between vimentin- and actin-based membrane protrusions are not understood. We report here that CARMIL2 (capping protein, Arp2/3, myosin-I linker 2) provides such a molecular link. CARMIL2 localizes to vimentin, regulates actin capping protein (CP), and binds to membranes. CARMIL2 is necessary for invadopodia formation, as well as cell polarity, lamellipodial assembly, membrane ruffling, macropinocytosis, and collective cell migration. Using point mutants and chimeras with defined biochemical and cellular properties, we discovered that localization to vimentin and CP binding are both essential for the function of CARMIL2 in cells. On the basis of these results, we propose a model in which dynamic vimentin filaments target CARMIL2 to critical membrane-associated locations, where CARMIL2 regulates CP, and thus actin assembly, to create cell protrusions.
Are American black bears in an agricultural landscape being sustained by crops?
Authors: Ditmer Mark A. , Garshelis David L. , Noyce Karen V. , Haveles Andrew W. , Fieberg John R.
Published: October 2015

Human-altered landscapes are thought to reduce habitat quality for many forest-dependent species, but some omnivorous, opportunist species take advantage of human-related food sources, such as garbage and crops. It is unknown, however, whether anthropogenic foods can sustain populations in areas with relatively little natural habitat. We studied (2007–2012) a population of American black bears ( Ursus americanus ) at the western periphery of their range in Minnesota, in a landscape that was heavily impacted by agriculture (~50%). We estimated the dietary contributions of corn and sunflowers (2–4% of the landscape) versus seasonally available natural foods (spring vegetation, ants, deer, fruit, and nuts) with stable isotope analyses (δ 13 C and δ 15 N) of 110 hair samples from 51 bears. We identified associations between diet and sex, age, body size and condition, reproductive status, space use, habitat connectivity, and natural food abundance. At the population level, adult males and adult females without cubs consumed considerable crops in fall (95% credible intervals: males = 19–46% of diet, females = 10–40%), but females with cubs and juvenile bears rarely consumed crops. Individual estimates of crop consumption were positively correlated with the proportion of GPS-collar locations in crop fields. Females, but not males, decreased crop consumption in years with high availability of natural fall foods. Further, the degree of crop consumption was more closely tied to local crop availability and landscape composition in females than in males. Weight and fat were positively correlated with crop use for both sexes, and males’ use of crops also increased with their physical stature, suggesting that crops provided substantial caloric benefits to bears and that social dominance may have influenced foraging decisions. However, a large segment of this bear population (44% of sampled bear–years) made little use of crops, and crops accounted for more than half the fall diet for only 14% of the population. Whereas some bears clearly benefited from consumption of crops, we conclude that a population of bears could be sustained in this largely agricultural region even without crops as a food source.
MHD simulation for investigating the evolutionary path of a solar magnetic field that emerges, structures itself, erupts, and produces a flare
Authors: Magara Tetsuya
Published: October 2015

We performed a long-term magnetohydrodynamic simulation to reproduce the self-consistent evolution of a solar magnetic field, which comprises the initial phase when a magnetic flux tube emerges below the solar surface, the formation of a magnetic structure giving rise to a flux rope and sigmoid in the solar corona, and the final phase during which a flux rope erupts, followed by a flare with plasmoid ejection. By seamlessly reproducing dynamic processes involved in emergence, formation, eruption, and magnetic reconnection, we demonstrate the entire evolutionary path of an emerging flux tube leading to the onset of a flare.
Plant Growth Regulator Effects on Bacterial Etiolation of Creeping Bentgrass Putting Green Turf Caused by Acidovorax avenae
Authors: Roberts Joseph A. , Ritchie David F. , Kerns James P.
Published: October 2015

Bacterial etiolation, caused by Acidovorax avenae, is a widespread problem in creeping bentgrass putting green turf. The symptoms normally appear as abnormally elongated turfgrass stems and leaves. Observations at multiple field sites suggest the involvement of plant growth regulators (i.e., GA-biosynthesis inhibitors) commonly applied to turf, alluding to a phytohormone imbalance caused by the bacterium. A 2-year field study examined the effects of trinexapac-ethyl, flurprimidol, and paclobutrazol on bacterial etiolation severity caused by A. avenae. Trinexapac-ethyl applied at 0.05 kg a.i. ha−1 every 7 days and 0.10 kg ha−1 every 14 days increased etiolation compared with all other treatments in both years. Flurprimidol and paclobutrazol were not different from the control but high-rate applications caused phytotoxicity that lowered turf quality early in 2014. When the etiolated turfgrass was removed with mowing, turfgrass treated with trinexapac-ethyl exhibited the highest turfgrass quality on most rating dates. Results from this work illustrate that using plant growth regulator materials with different modes of action is a solution to managing creeping bentgrass growth while limiting the potential for bacterial etiolation outbreaks.
Impact of Alternative Fungicides on Grape Downy Mildew Control and Vine Growth and Development
Authors: Romanazzi Gianfranco , Mancini Valeria , Feliziani Erica , Servili Andrea , Endeshaw Solomon , Neri Davide
Published: October 2015

Grapevine downy mildew (GDM) is one of the most serious diseases of grapevines. With limitations in the use of copper-based products imposed for organic agriculture by the European Union, research for alternatives is encouraged. The aim of this research was to follow a 2-year trial to evaluate the control of GDM using some alternative compounds, and to determine their effects on shoot growth, plant photosynthesis, and grape quality and quantity. Under low disease pressure, Bordeaux mixture, copper hydroxide, laminarin combined with low copper, and 0.5 and 0.8% chitosan had the lowest GDM incidence, reduced on leaves by 96, 95, 75, 56, and 81%, respectively, compared with the untreated control in the last survey. With high disease pressure, Bordeaux mixture, laminarin combined with Saccharomyces extracts, and 0.5 and 0.8% chitosan had the lowest GDM incidence, reduced on grape by 86, 37, 66, and 75%, respectively, compared with the untreated control in the survey of mid-July. Chitosan at 0.8% lowered net photosynthesis, due to reduced stomatal conductance, leaf area, and dry weight, with no negative effects observed on the quantity of the grape berries and the quality parameters of their juice. Among the alternatives to copper, chitosan provided the best GDM protection and reduced the vigor of the vegetation, inducing physiological changes without negative effects on grape production.
Low Prevalence of Anterior and Posterior Cruciate Ligament Injuries in Patients With Achondroplasia
Authors: Brooks Jaysson T. , Ramji Alim F. , Lyapustina Tatyana A. , Yost Mary T. , Ain Michael C.
Published: October 2015

Background:

Anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) injuries and their subsequent reconstructions are common in the general population, but there has been no research regarding ACL or PCL injuries in patients with achondroplasia, the most common skeletal dysplasia. Our goals were to (1) evaluate the prevalence of ACL and PCL injuries in adolescents and adults with achondroplasia, (2) compare this prevalence with that reported for the general population, (3) determine how many patients with ACL or PCL injuries underwent ligament reconstruction as treatment, and (4) determine patient activity levels as they relate to the rate of ACL/PCL injuries and reconstructions.

Methods:

We reviewed medical records of 430 patients with achondroplasia seen in the senior author’s clinic from 2002 through 2014. Demographic data were reviewed, as well as any documentation of ACL or PCL injury or reconstruction. We called all 430 patients by telephone, and 148 agreed to participate in our survey, whereas 1 declined. We asked these patients about their history of ACL or PCL injury or reconstruction, as well as current and past physical activity levels.

Results:

No ACL or PCL injuries were found on chart review. One patient reached by telephone reported an ACL injury that did not require reconstruction. This yielded a theoretical prevalence of 3/430 (0.7%). Of the 148 patients surveyed, 43 (29%) reported low physical activity, 75 (51%) reported moderate physical activity, and 26 (17%) reported high physical activity. There was no significant difference in the rate of ACL injury when stratified by physical activity level (P=0.102).

Conclusions:

ACL and PCL injuries and reconstructions are extremely rare in patients with achondroplasia, which cannot be completely ascribed to a low level of physical activity. One possible explanation is that patients with achondroplasia, on an average, have a more anterior tibial slope compared with those without achondroplasia, which decreases the force generated within the ACL and may protect against ACL injury. Further research is needed to explore possible causes.

Level of Evidence:

Level IV—retrospective review.
Preliminary Results of the Induced Membrane Technique for the Reconstruction of Large Bone Defects
Authors: Mansour Toni M. , Ghanem Ismat B.
Published: October 2015

Background:

During past decades, gradual bone transplant using external fixators and vascularized fibular or rib transplants widely contributed to solve difficult problems related to the reconstruction of large bone defects in children. However, these surgeries are time consuming and require specialized surgical skills, not always available in a general hospital setting, mainly in rural areas.

Purpose:

To report the preliminary results of the more recently described induced membrane technique in a consecutive series of 8 children and to identify some factors related to the procedure’s success.

Methods:

Nine consecutive children with bone defects ranging from 5 to 14 cm were included in the study. The age at surgery ranged from 3 to 16 years. There were 3 congenital pseudarthrosis (CP) of the fibula, 1 CP of the tibia, 1 Ewing sarcoma of the tibia, 1 Ewing sarcoma of the ulna, 1 tibial osteosarcoma, 1 fibular osteosarcoma, and 1 chronic diffuse tibial osteomyelitis. The procedure was performed according to the original Masquelet’s description in 2 stages. Follow-up ranged from 1 to 7 years.

Results:

The child with tibial osteosarcoma died 3 months after the surgery from complications related to chemotherapy. Among the 8 remaining children, 6 healed uneventfully, and 2 required revision with additional grafting and/or better internal fixation, one with Ewing sarcoma of the tibia and a 13-cm bone defect and the second with CP of the fibula. Both of them had suboptimal internal stabilization.

Conclusions:

The induced membrane technique is a useful, efficient, and simple alternative to highly specialized surgical procedures used for the reconstruction of large bone defects in children. Risk factors for failure include chemotherapy, suboptimal bone fixation, and persistent axial malalignment.

Level of Evidence:

Level IV.
Integrated versus fragmented implementation of complex innovations in acute health care
Authors: Woiceshyn Jaana , Blades Kenneth , Pendharkar Sachin R.
Published: October 2015

Background:

Increased demand and escalating costs necessitate innovation in health care. The challenge is to implement complex innovations—those that require coordinated use across the adopting organization to have the intended benefits.

Purpose:

We wanted to understand why and how two of five similar hospitals associated with the same health care authority made more progress with implementing a complex inpatient discharge innovation whereas the other three experienced more difficulties in doing so.

Methodology:

We conducted a qualitative comparative case study of the implementation process at five comparable urban hospitals adopting the same inpatient discharge innovation mandated by their health care authority. We analyzed documents and conducted 39 interviews of the health care authority and hospital executives and frontline managers across the five sites over a 1-year period while the implementation was ongoing.

Findings:

In two and a half years, two of the participating hospitals had made significant progress with implementing the innovation and had begun to realize benefits; they exemplified an integrated implementation mode. Three sites had made minimal progress, following a fragmented implementation mode. In the former mode, a semiautonomous health care organization developed a clear overall purpose and chose one umbrella initiative to implement it. The integrative initiative subsumed the rest and guided resource allocation and the practices of hospital executives, frontline managers, and staff who had bought into it. In contrast, in the fragmented implementation mode, the health care authority had several overlapping, competing innovations that overwhelmed the sites and impeded their implementation.

Practice Implications:

Implementing a complex innovation across hospital sites required (a) early prioritization of one initiative as integrative, (b) the commitment of additional (traded off or new) human resources, (c) deliberate upfront planning and continual support for and evaluation of implementation, and (d) allowance for local customization within the general principles of standardization.
The Expression of Cyclin D1, VEGF, EZH2, and H3K27me3 in Atypical Teratoid/Rhabdoid Tumors of the CNS: A Possible Role in Targeted Therapy
Authors: Kakkar Aanchal , Biswas Ahitagni , Goyal Nishant , Suri Vaishali , Sharma Mehar C. , Gupta Deepak , Julka Pramod K. , Sarkar Chitra
Published: October 2015

Atypical teratoid/rhabdoid tumor (AT/RT) is an uncommon malignancy with a dismal outcome, which responds poorly to multimodality therapies. Animal studies have revealed Cyclin D1 as a possible therapeutic target. The addition of vascular endothelial growth factor (VEGF) inhibitors to chemotherapeutic regimens has shown promising results in pediatric central nervous system tumors. Enhancer of Zeste homolog 2 (EZH2) overexpression has been implicated in various cancers, including medulloblastomas. H3K27me3 is a new marker for pediatric high-grade gliomas. However, their role in AT/RT has not been evaluated sufficiently. We retrieved cases of AT/RT, and reviewed their clinical data and histopathologic features. Immunohistochemistry for Cyclin D1, VEGF, EZH2, and H3K27me3 was performed. Follow-up was noted when available. Fourteen cases of AT/RT were identified (mean age, 3.4 y; range, 10 mo to 8 y). Cyclin D1 immunopositivity was noted in all cases [labeling index (LI): 5% to 98%; mean, 41.3%]. VEGF positivity was seen in 83.3% of the cases. All cases showed EZH2 overexpression (mean LI, 74.3%; range, 32% to 96%). Reduction of H3K27me3 expression was noted in 63% of the cases, with no correlation with EZH2 LI. Two patients died of postoperative complications. Of the rest, follow-up was available for 7 (range, 7 to 120 wk): 1 achieved clinical remission, whereas 6 developed progressive disease, including 3 deaths. Varying degrees of immunoreactivity to Cyclin D1, VEGF, and EZH2 were noted in the majority of the AT/RTs, and detection of these markers may be of value in the development of novel therapeutic agents and in determining which patients can benefit from them. AT/RTs show reduction in H3K27me3 expression, independent of EZH2 expression, indicating that their interaction requires further evaluation.