bluuebunny/crossref_metadata_2025 huggingface dataset:
Enfants de la loi 101 et parcours scolaires linguistiques : le récit des jeunes issus de l’immigration à Montréal
Authors: Magnan Marie-Odile , Darchinian Fahimeh
Published: May 2015

Cet article aborde l’expérience scolaire et les logiques d’orientation des jeunes issus de l’immigration qui ont dû fréquenter l’école québécoise francophone et qui ont poursuivi des études postsecondaires à Montréal en anglais. Inspirée d’une sociologie de l’acteur scolaire, l’analyse de récits de vie révèle que le rapport développé par ces jeunes face à l’école francophone et la culture d’orientation véhiculée par leurs pairs et leurs parents ont un impact sur leur choix d’étudier en anglais au postsecondaire. L’analyse des discours permet de constater des frontières intergroupes au secondaire entre les « jeunes issus de l’immigration » et les « francophones québécois ». En conclusion, une réflexion sur le curriculum formel et informel est proposée afin d’améliorer le vivre ensemble.
Developing a Global Perspective in / FOR Science Teacher Education: The Case of Pollination
Authors: Reis Giuliano
Published: May 2015

Science educators at all levels continuously struggle to keep pace with the rapidly developing understanding of the causes and potential solutions to current environmental issues while also trying to enthuse a new generation of passionate and knowledgeable scientists. However, how can future science teachers make science education more attractive ad meaningful to their students? The present paper describes (in a narrative style) an instructional practice that has been performed within a secondary science methods course in a teacher preparation program in Canada. More specifically, it draws on ideas presented in Agenda 21 and the United Nation’s Millennium Development Goals to study the (often neglected) socio-environmental aspects of pollination. Ultimately, the proposed activity aims at promoting the ability of pre-service high school biology teachers to adopt a global education perspective on the science curriculum by (a) recognizing the unintended negative ecological impact caused by humanity’s pursuit of sustainable development and sustainability and (b) reexamining traditional conceptions of scientific and ecological literacies.
Dynamic BMP signaling polarized by Toll patterns the dorsoventral axis in a hemimetabolous insect
Authors: Sachs Lena , Chen Yen-Ta , Drechsler Axel , Lynch Jeremy A , Panfilio Kristen A , Lässig Michael , Berg Johannes , Roth Siegfried
Published: May 2015

Toll-dependent patterning of the dorsoventral axis in Drosophila represents one of the best understood gene regulatory networks. However, its evolutionary origin has remained elusive. Outside the insects Toll is not known for a patterning function, but rather for a role in pathogen defense. Here, we show that in the milkweed bug Oncopeltus fasciatus, whose lineage split from Drosophila's more than 350 million years ago, Toll is only required to polarize a dynamic BMP signaling network. A theoretical model reveals that this network has self-regulatory properties and that shallow Toll signaling gradients are sufficient to initiate axis formation. Such gradients can account for the experimentally observed twinning of insect embryos upon egg fragmentation and might have evolved from a state of uniform Toll activity associated with protecting insect eggs against pathogens.
Asynchronous variation in the East Asian winter monsoon during the Holocene
Authors: Zhang Xiaojian , Jin Liya , Li Na
Published: May 2015

The East Asian winter monsoon (EAWM) is one of the most active components of the global climate system. Climate anomalies associated with the EAWM differ between extratropical and tropical regions due to the EAWM's meridional extent. Spatial differences in the EAWM variability on centennial and millennial time scales during the Holocene have not been well understood. This study describes Holocene spatiotemporal features of the EAWM based on comparisons of proxy records and climate simulations. The analysis specifically compared four proxy records located throughout China to assess the EAWM's spatial variability during the Holocene. These records indicate a stronger EAWM during the early Holocene than that during the late Holocene. The EAWM also shows a rapid, asynchronous decline from northwestern to southeastern China. The EAWM declined in northwestern China from 10 to 7.5 ka B.P., whereas the decline did not occur in southern China and the eastern Tibetan Plateau until 6–4.5 ka B.P. Coupled equilibrium and transient simulations of climate evolution during the Holocene indicate that the decline of the EAWM from 10 to 7.5 ka B.P. was probably caused by melting of Northern Hemisphere (NH) ice sheets and enhanced Atlantic meridional overturning circulation (AMOC). The decline of the EAWM from 6 to 4.5 ka B.P. over the eastern Tibetan Plateau and southern China is related to an abrupt increase in sea surface temperatures (SSTs) of the tropical western Indian Ocean. We therefore argue that the regional shift in EAWM intensity was probably related to a distinguishing response to high‐latitude (NH ice sheets and AMOC) and low‐latitude (tropical SSTs) forcings.
Comparing dust flux records from the Subarctic North Pacific and Greenland: Implications for atmospheric transport to Greenland and for the application of dust as a chronostratigraphic tool
Authors: Serno Sascha , Winckler Gisela , Anderson Robert F. , Maier Edith , Ren Haojia , Gersonde Rainer , Haug Gerald H.
Published: May 2015

We present a new record of eolian dust flux to the western Subarctic North Pacific (SNP) covering the past 27,000 years based on a core from the Detroit Seamount. Comparing the SNP dust record to the North Greenland Ice Core Project (NGRIP) ice core record shows significant differences in the amplitude of dust changes to the two regions during the last deglaciation, while the timing of abrupt changes is synchronous. If dust deposition in the SNP faithfully records its mobilization in East Asian source regions, then the difference in the relative amplitude must reflect climate‐related changes in atmospheric dust transport to Greenland. Based on the synchronicity in the timing of dust changes in the SNP and Greenland, we tie abrupt deglacial transitions in the 230Th‐normalized 4He flux record to corresponding transitions in the well‐dated NGRIP dust flux record to provide a new chronostratigraphic technique for marine sediments from the SNP. Results from this technique are complemented by radiocarbon dating, which allows us to independently constrain radiocarbon paleoreservoir ages. We find paleoreservoir ages of 745 ± 140 years at 11,653 year B.P., 680 ± 228 years at 14,630 year B.P., and 790 ± 498 years at 23,290 year B.P. Our reconstructed paleoreservoir ages are consistent with modern surface water reservoir ages in the western SNP. Good temporal synchronicity between eolian dust records from the Subantarctic Atlantic and equatorial Pacific and the ice core record from Antarctica supports the reliability of the proposed dust tuning method to be used more widely in other global ocean regions.
Estimation of the bed shear stress in vegetated and bare channels with smooth beds
Authors: Yang Judy Q. , Kerger Francois , Nepf Heidi M.
Published: May 2015

The shear stress at the bed of a channel influences important benthic processes such as sediment transport. Several methods exist to estimate the bed shear stress in bare channels without vegetation, but most of these are not appropriate for vegetated channels due to the impact of vegetation on the velocity profile and turbulence production. This study proposes a new model to estimate the bed shear stress in both vegetated and bare channels with smooth beds. The model, which is supported by measurements, indicates that for both bare and vegetated channels with smooth beds, within a viscous sublayer at the bed, the viscous stress decreases linearly with increasing distance from the bed, resulting in a parabolic velocity profile at the bed. For bare channels, the model describes the velocity profile in the overlap region of the Law of the Wall. For emergent canopies of sufficient density (frontal area per unit canopy volume
), the thickness of the linear‐stress layer is set by the stem diameter, leading to a simple estimate for bed shear stress.
Investigating the final seismic swarm before the Iquique‐Pisagua 2014 Mw 8.1 by comparison of continuous GPS and seismic foreshock data
Authors: Bedford Jonathan , Moreno Marcos , Schurr Bernd , Bartsch Mitja , Oncken Onno
Published: May 2015

Preexisting networks of seismometers and continuous GPS in Northern Chile successfully captured surface motions and seismicity leading up to the 1 April Mw 8.1. Here we compare continuous GPS (cGPS) with predictions of seismic dislocations for the final foreshock swarm, beginning with the 16 March Mw 6.7. Results show that the cumulative cGPS motion can be largely explained by seismic slip because evolutions of cGPS positions for most stations stay within the ranges of seismic predictions (given sensible ranges of assumed source errors). However, cGPS motions between 18–21 and 25–31 March outpace seismic predictions, supporting the existence of aseismic transients that were most probably the afterslip from preceding bursts of seismicity. A parameter search reveals that the 16 March Mw 6.7 cGPS displacements can be recreated with a fault plane significantly rotated anticlockwise from the strike of the plate interface, suggesting that failure was on a structure other than the plate interface.
Emergence of short crestedness in originally unidirectional nonlinear waves
Authors: de Pinho Uggo F. , Babanin Alexander V.
Published: May 2015

Ocean waves forced by the wind are multidirectional, even if the wind direction is steady. Directionality can occur due to superposition of long‐crested waves propagating at angle to each other. Lateral modulation of the wave crests, however, also takes place for strictly unidirectional waves, due to nonlinear effects. Here short crestedness of unidirectional waves is investigated. A series of experiments on the lateral instability of monochromatic, deep water, unidirectional, initially long‐crested steep waves was performed in a large wave basin. The cross modulation of wave crests is clearly visible; its magnitude depends on the wave steepness in the wave propagation direction. Its spatial scale is comparable with the wavelength. Thus, short crestedness is an inherent feature of nonlinear waves and should be taken into account when estimating directional properties of ocean waves.
Relativistic electron precipitation induced by EMIC‐triggered emissions in a dipole magnetosphere
Authors: Kubota Yuko , Omura Yoshiharu , Summers Danny
Published: May 2015

We perform test particle simulations of relativistic electrons interacting with electromagnetic ion cyclotron (EMIC)‐triggered emissions in the plasmasphere. EMIC‐triggered emissions are generated by energetic protons injected into the inner magnetosphere. EMIC‐triggered emissions are characterized by large wave amplitudes, rising‐tone frequencies, and coherent left‐hand circularly polarized waves. We study trajectories of relativistic radiation belt electrons drifting eastward interacting with longitudinally distributed EMIC‐triggered emissions. Some electrons are trapped by wave potentials and efficiently guided down to lower pitch angles. Repeated interactions occur due to the mirror motion and result in the scattering of particles into the loss cone. We use two EMIC wave models for the test particle simulations. One assumes that the wave amplitude is constant, and the other assumes a time‐dependent wave amplitude that characterizes subpackets. Both model waves are resonant with 0.5–6.0 MeV electrons and precipitate them. Electrons in the energy range 1.1–3.0 MeV are precipitated most efficiently. Approximately 50% of the total injected number of 1.1–3.0 MeV electrons are precipitated in a timescale of 2 min. We obtain the relativistic electron distribution in equatorial pitch angle and in pitch angle at the atmosphere. Further, we determine the timing and longitudinal location of the relativistic electron precipitation with respect to different particle energies.
Size‐Dependent Optical Absorption of Layered MoS2 and DNA Oligonucleotides Induced Dispersion Behavior for Label‐Free Detection of Single‐Nucleotide Polymorphism
Authors: Li Bang Lin , Zou Hao Lin , Lu Lu , Yang Yu , Lei Jing Lei , Luo Hong Qun , Li Nian Bing
Published: May 2015

Size‐dependent optical absorption of semiconductive (2H) layered molybdenum disulfide (MoS2), exhibiting great discrimination abilities to single‐ and double‐stranded DNA (ssDNA) and (dsDNA), is studied. In the presence of high concentration of salt, layered MoS2 trends to aggregate rapidly, leading to the increases of sizes in both vertical and lateral dimensions of the nanosheets, which results from the interplay between van der Waals attraction and electrical double‐layer repulsion. Meanwhile, the aggregation behavior of layered MoS2 is remarkably inhibited by the synergistic effects of DNA oligonucleotides. ssDNA can adsorb on the surface of layered MoS2, resulting in a great dispersion, even in the presence of high concentration of salt, while the dispersion behavior is weakened when ssDNA is replaced by dsDNA. Whereas compared to graphene with zero bandgap energy, layered MoS2, with semiconductive properties, exhibits great characteristic optical absorption in visible wavelength region devoted to exploring the aggregation behavior of layered MoS2. Therefore, DNA oligonucleotides induced size control of layered MoS2, contributing to the regular change of its characteristic absorption in visible region, is considered a label‐free bioassay for the detection of single‐nucleotide polymorphism. Due to its easy operation and high specificity, it is expected that the proposed assay holds great promise for further applications.
Sn‐Based Nanoparticles Encapsulated in a Porous 3D Graphene Network: Advanced Anodes for High‐Rate and Long Life Li‐Ion Batteries
Authors: Wu Chao , Maier Joachim , Yu Yan
Published: May 2015

Sn‐based materials have triggered significant research efforts as anodes for lithium‐storage because of their high theoretical capacity. However, the practical applications of Sn‐based materials are hindered by low capacity release and poor cycle life, which are mainly caused by structural pulverization and large volume changes on cycling. Herein, a surfactant‐assisted assembly method is developed to fabricate 3D nanoarchitectures in which Sn‐based nanoparticles are encapsulated by a porous graphene network. More precisely, the graphene forms a 3D cellular network, the interstices of which only partially filled by the electroactive masses, thus establishing a high concentration of interconnected nanosized pores. While the graphene‐network itself guarantees fast electron transfer, it is the characteristic presence of nanosized pores in our network that leads to the favorable rate capability and cycling stability by i) accommodating the large volume expansion of Sn‐based nanoparticles to ensure integrity of the 3D framework upon cycling and ii) enabling rapid access of Li‐ions into Sn‐based nanoparticles, which are in addition prevented from agglomerating. As a result, the 3D Sn‐based nanoarchitectures deliver excellent electrochemical properties including high rate capability and stable cycle performance. Importantly, this strategy provides a new pathway for the rational engineering of anode materials with large volume changes to achieve improved electrochemical performances.
Light Weight and Flexible High‐Performance Diagnostic Platform
Authors: Karnaushenko Daniil , Ibarlucea Bergoi , Lee Sanghun , Lin Gungun , Baraban Larysa , Pregl Sebastian , Melzer Michael , Makarov Denys , Weber Walter M. , Mikolajick Thomas , Schmidt Oliver G. , Cuniberti Gianaurelio
Published: May 2015

A flexible diagnostic platform is realized and its performance is demonstrated for early detection of avian influenza virus (AIV) subtype H1N1 DNA sequences. The key component of the platform is high‐performance biosensors based on high output currents and low power dissipation Si nanowire field effect transistors (SiNW‐FETs) fabricated on flexible 100 μm thick polyimide foils. The devices on a polymeric support are about ten times lighter compared to their rigid counterparts on Si wafers and can be prepared on large areas. While the latter potentially allows reducing the fabrication costs per device, the former makes them cost efficient for high‐volume delivery to medical institutions in, e.g., developing countries. The flexible devices withstand bending down to a 7.5 mm radius and do not degrade in performance even after 1000 consecutive bending cycles. In addition to these remarkable mechanical properties, on the analytic side, the diagnostic platform allows fast detection of specific DNA sequences of AIV subtype H1N1 with a limit of detection of 40 × 10−12 m within 30 min suggesting its suitability for early stage disease diagnosis.
Role of Cytoskeletal Tension in the Induction of Cardiomyogenic Differentiation in Micropatterned Human Mesenchymal Stem Cell
Authors: Tijore Ajay , Cai Pingqiang , Nai Mui Hoon , Zhuyun Li , Yu Wang , Tay Chor Yong , Lim Chwee Teck , Chen Xiaodong , Tan Lay Poh
Published: May 2015

The role of biophysical induction methods such as cell micropatterning in stem cell differentiation has been well documented previously. However, the underlying mechanistic linkage of the engineered cell shape to directed lineage commitment remains poorly understood. Here, it is reported that micropatterning plays an important role in regulating the optimal cytoskeletal tension development in human mesenchymal stem cell (hMSC) via cell mechanotransduction pathways to induce cardiomyogenic differentiation. Cells are grown on fibronectin strip patterns to control cell polarization and morphology. These patterned cells eventually show directed commitment toward the myocardial lineage. The cell's mechanical properties (cell stiffness and cell traction forces) are observed to be very different for cells that have committed to the myocardial lineage when compared with that of control. These committed cells have mechanical properties that are significantly lower indicating a correlation between the micropatterning‐induced differentiation and actomyosin‐generated cytoskeletal tension within patterned cells. To study this correlation, patterned cells are treated with RhoA pathway inhibitor. Severely down‐regulated cardiomyogenic marker expression is observed in those treated patterned cells, thus emphasizing the direct dependence of hMSCs differentiation fate on the cytoskeletal tension.
Atomic Defects in Two Dimensional Materials
Authors: Rasool Haider I. , Ophus Colin , Zettl Alex
Published: May 2015

Atomic defects in crystalline structures have pronounced affects on their bulk properties. Aberration‐corrected transmission electron microscopy has proved to be a powerful characterization tool for understanding the bonding structure of defects in materials. In this article, recent results on the characterization of defect structures in two dimensional materials are discussed. The dynamic behavior of defects in graphene shows the stability of zigzag edges of the material and gives insights into the dislocation motion. Polycrystalline graphene is characterized using advanced electron microscopy techniques, revealing the global crystal structure of the material, as well as atomic‐resolution observation of the carbon atom positions between neighboring crystal grains. Studies of hexagonal boron nitride (hBN) are also visited, highlighting the interlayer bonding, which occurs upon defect formation, and characterization of grain boundary structures. Lastly, defect structures in monolayer polycrystalline transition metal dichalcogenides grown by CVD are discussed.
Rotatable Diffraction Gratings Based on Cholesteric Liquid Crystals with Phototunable Helix Pitch
Authors: Ryabchun Alexander , Bobrovsky Alexey , Stumpe Joachim , Shibaev Valery
Published: May 2015

A novel type of rotatable diffraction volume gratings based on cholesteric liquid crystals with phototunable helix pitch is elaborated. For this purpose the cholesteric liquid crystalline mixture with high helix pitch tunability and reversible photoinduced helix handedness inversion containing azobenzene‐derivative of the chiral‐photochromic dopant is developed. It was shown that the prepared cholesteric mixture under the hybrid (homeotropic – planar) boundary conditions spontaneously forms a well‐oriented striped domain texture which acts as a phase grating. Under the effect of light the changes of helix pitch take place due to the molecular photoreaction of chiral‐photochromic dopant causing the variation of the period of striped domain structure and its rotation. The clockwise and counterclockwise rotation of the obtained gratings can be achieved by switching between UV and visible light, correspondingly. The maximum angle of the continuous rotation is ≈690°, while the total rotation caused by UV light illumination reaches ≈1220°. The creation of a variety of complex‐organized structures by local light exposure of the cholesteric domain texture is demonstrated. The observed advanced photooptical effects have potentially wide and important applications from scientific and applied points of view.
Nonlinear Thf‐Fxlms Algorithm For Active Noise Control With Loudspeaker Nonlinearity
Authors: Ghasemi Sepehr , Kamil Raja , Marhaban Mohammad Hamiruce
Published: May 2015

Adaptive algorithms are prevalently applied in the design of nonlinear active noise control (ANC) systems. The most important nonlinearity in ANC is the saturation effect produced by the electro‐acoustical sensors and transducers. The dominant saturation nonlinearity is in the transducers, which can be represented by a Wiener model. An effective solution to mitigate such nonlinear distortion is to employ the Nonlinear Filtered‐X Least Mean Square (NLFXLMS) algorithm. The controller compensates the nonlinearity using a model of the saturation effect represented by the scaled error function (SEF). However, the NLFXLMS is limited by two practical issues such that the degree of nonlinearity has to be known in advance and the SEF cannot be evaluated in real time. In this work, the NLFXLMS algorithm is modified by incorporating the tangential hyperbolic function (THF) to model the saturation effect of the loudspeaker. The proposed THF‐NLFXLMS algorithm, models the nonlinear secondary path and applies the estimated degree of nonlinearity in the control algorithm design. The results show that the Wiener secondary path, with saturation nonlinearity represented by SEF, can be modelled by THF with a certain degree of accuracy and can yield a reasonable estimate of the degree of nonlinearity. The performance of the proposed algorithm is comparable with the benchmark NLFXLMS and is superior to the conventional FXLMS as well as the second order Volterra algorithm of similar computational complexity with the proposed algorithm.
Adaptive Control for Simultaneous Stabilization and Tracking of Unicycle Mobile Robots
Authors: Miao Zhiqiang , Wang Yaonan
Published: May 2015

A novel time‐varying adaptive controller at the torque level is proposed to simultaneously solve the stabilization and the tracking problem of unicycle mobile robots with unknown dynamic parameters. The idea underlying the controller is intuitively simple: rather than switching between two different types of controllers according to the a priori knowledge of the reference velocities being persistently exciting or not, a new time‐varying signal is introduced to make the single controller capable of adaptively, smoothly, and gradually converting between stabilizer and tracker depending on the instantaneous and past information of the reference velocities. Our control development is based on Lyapunov's direct method and the backstepping technique. Adaptive control techniques are used to deal with parametric uncertainties. The outstanding feature of our controller is computationally simple due to its full use of the existing results on stabilization and tracking control for unicycle robots. With our approach, robots can globally follow a large class of paths including a straight line, a circle, a path approaching a set‐point, or just a set‐point using a single controller. Simulation results for a unicycle‐type mobile robot are provided to illustrate the effectiveness of the proposed controller.
Optimal Distribution Control Of Non‐Linear Tire Force Of Electric Vehicles With In‐Wheel Motors
Authors: Li Boyuan , Du Haiping , Li Weihua
Published: May 2015

An over‐actuated control system has the advantage of being able to use redundant actuators to reconfigure the control system and it can realize fault tolerant control. In order to achieve improved vehicle stability and handling performance for electric vehicles with in‐wheel steering and driving motors, the control of the vehicle body slip angle and yaw rate is actually an over‐actuated control problem. To obtain the optimal solution for this control problem, this study proposes a two‐level tire force distribution control method, where the upper level controller calculates the desired lateral and longitudinal forces generated by friction on the tire of each wheel according to the driver's steering and driving inputs. The lower level controller maps the desired tire forces into the input of each steering actuator and driving actuator. Unlike the linear mapping method applied in most of the current research, this study develops a proportional‐integral (PI) controller for each actuator so that the non‐linear tire characteristics can be counteracted. In addition, since the PI controllers for eight actuators (four steering actuators and four driving actuators) have a total of 16 control gains to be determined, a genetic algorithm is applied to accurately determine these control gains. The simulation results are presented to validate the control performance of the proposed tire force allocation method.
A novel red‐emitting phosphor, KAl1‐xPO4Cl:Eux3+ (0.1 ≤ x ≤ 1.0)
Authors: Akojwar Ashish , Shinde K. N. , Singh Roshani , Dhoble S. J. , Kokode N. S.
Published: May 2015

A series of phosphors KAl1‐xPO4Cl:Eux3+ (0.1 ≤ x ≤ 1.0) was synthesized using a facile combustion method using urea as a fuel and their structural, morphological and photoluminescence properties were investigated. It was found that the particle size was in the range of 1–2 µm with an irregular shape. The f–f transitions of Eu3+ in the host lattice were assigned and discussed. The excitation and emission spectra indicated that this phosphor can be efficiently excited by ultraviolet (395 nm), and exhibit reddish orange emission corresponding to the 5D0→7FJ (J = 0, 1, 2) transitions of Eu3+. The impact of the Eu3+ concentration on the relative emission intensity was investigated, and the best doping concentration is 0.5. The present study suggests that the KAl0.5PO4Cl: Eu0.53+ phosphor is a strong candidate as a red component for phosphor‐ converted white light‐emitting diodes (LEDs). Copyright © 2015 John Wiley & Sons, Ltd.
High‐rate volatile fatty acid (VFA) production by a granular sludge process at low pH
Authors: Tamis J. , Joosse B.M. , Loosdrecht M.C.M.van , Kleerebezem R.
Published: May 2015

Volatile fatty acids (VFA) are proposed platform molecules for the production of basic chemicals and polymers from organic waste streams. In this study we developed a granular sludge process to produce VFA at high rate, yield and purity while minimizing potential operational costs. A lab‐scale anaerobic sequencing batch reactor (ASBR) was fed with 10 g l−1 glucose as model substrate. Inclusion of a short (2 min) settling phase before effluent discharge enabled effective granulation and very high volumetric conversion rates of 150–300 gCOD l−1 d−1 were observed during glucose conversion. The product spectrum remained similar at the tested pH range with acetate and butyrate as the main products, and a total VFA yield of 60–70% on chemical oxygen demand (COD) basis. The requirement for base addition for pH regulation could be reduced from 1.1 to 0.6 mol OH− (mol glucose)−1 by lowering the pH from 5.5 to 4.5. Solids concentrations in the effluent were 0.6 ± 0.3 g l−1 but could be reduced to 0.02 ± 0.01 g l−1 by introduction of an additional settling period of 5 min. The efficient production of VFA at low pH with a virtually solid‐free effluent increases the economic feasibility of waste‐based chemicals and polymer production. Biotechnol. Bioeng. 2015;112: 2248–2255. © 2015 Wiley Periodicals, Inc.
GC‐FID determination and pharmacokinetic studies of oleanolic acid in human serum
Authors: Rada Mirela , Castellano José María , Perona Javier S. , Guinda Ángeles
Published: May 2015

Analytical interest of OA determination in human serum has increased owing to the increasing interest in pharmaceutical research by pharmaceutical properties. A simple, specific, precise and accurate GC method with flame ionization detector (FID) developed and validated for the determination of oleanolic acid (OA) in human serum (HS). To an aliquot of HS, internal standard was added and a combination of liquid–liquid extraction with a mixture of diethyl ether‐isopropyl alcohol, filtration and consecutive GC resulted in separation and quantification of OA. The organic phase was analyzed using a GC system equipped with a 30 × 0.25 mm i.d. Rtx‐65TG capillary column and FID detection. Total chromatographic time was 10 min and no interfering peaks from endogenous components in blank serum were observed. The OA/internal standard peak area ratio was linearly fitted to the OA concentration (r = 0.992) over the range 10–1500 ng/mL. The mean serum extraction recovery of OA was 96.7 ± 1.0% and the lower limit of quantification based on 5 mL of serum was 10.7 ng/mL. The intra‐day coefficient of variation ranged from 1.3 to 3.6% and inter‐day varied from 1.4 to 4.5%. The developed method was used to study the pharmacokinetics of OA after oral administration in humans. The assay was simple, sensitive, precise and accurate for the use in the study of the mechanisms of absorption and distribution of OA in humans. Copyright © 2015 John Wiley & Sons, Ltd.
A sensitive liquid chromatography–mass spectrometry bioanalytical assay for a novel anticancer candidate – ZMC1
Authors: Lin Hongxia , Yu Xin , Eng Oliver S. , Buckley Brian , Kong Ah‐Ng Tony , Bertino Joseph R. , Carpizo Darren R. , Gounder Murugesan K.
Published: May 2015

ZMC1 {azetidinecarbothioic acid, [1‐(2‐pyridinyl) ethylidene] hydrazide} is a lead compound being developed as one of the first mutant p53 targeted anti‐cancer drugs. Establishing a precise quantitative method is an integral component of this development. The aim of this study was to develop a sensitive LC/MS/MS assay suitable for assessing purity, stability and preclinical pharmacokinetic studies of ZMC1. Acetonitrile protein precipitation extraction was chosen for plasma sample preparation with satisfactory recovery (84.2–92.8%) for ZMC1. Chromatographic separation was achieved on an Xterra C18 column (50 × 4.6 mm, 3.5 µm) using a gradient elution with mobile phase of 0.1% formic acid in water and acetonitrile. ZMC1 and internal standard 2‐amino‐6‐bromobenzothiazole were identified using selected‐ion monitoring mode at m/z 235.2/178.2 and m/z 231.0/150.0 at retention times of 5.2 and 6.3 min, respectively. The method was validated with a linearity range of 3.9–500.0 ng/mL in human plasma and showed acceptable reproducibility with intra‐ and interday precisions <5.9 and 10.5%, and accuracy within ±5.4% of nominal values. This analytical method together with basic stability data in plasma and plasma binding experiments provides a reliable protocol for the study of ZMC1 pharmacokinetics. This will greatly facilitate the pre‐clinical development of this novel anti‐cancer drug. Copyright © 2015 John Wiley & Sons, Ltd.
Transcatheter fontan takedown
Authors: Hallbergson Anna , Mascio Christopher E. , Rome Jonathan J.
Published: May 2015

Early failure of the Fontan circulation is rare in the current era but remains associated with a high mortality rate. Surgical Fontan takedown has evolved as one of the strategies to stabilize the circulation, improve survival, and allow for a future attempt at Fontan completion. We have completed Transcatheter fontan takedown in three patients with extracardiac conduits 0.8–6 months following their Fontan operations. Superior vena cava flow was redirected into only the pulmonary arteries by occluding the conduit with a vascular plug between the pulmonary arteries and fenestration and unrestrictive inferior vena cava flow was redirected into only the atrium by stenting and enlarging the fenestration. There were no procedure related complications. All patients had resolution of large‐volume chylous pleural effusions. One patient had resolution of protein‐losing enteropathy, two patients had improvement of plastic bronchitis. Two of three patients remain alive at latest follow‐up (4–24 months). This early experience suggests that Transcatheter fontan takedown is technically feasible and may be an alternative to surgical takedown in select patients with early failure of the Fontan circulation. © 2015 Wiley Periodicals, Inc.
Transcatheter tricuspid valve‐in‐valve in patients with transvalvular device leads
Authors: Eleid Mackram F. , Asirvatham Samuel J. , Cabalka Allison K. , Hagler Donald J. , Noseworthy Peter A. , Taggart Nathaniel W. , Rihal Charanjit S.
Published: May 2015

Objective

To describe the effects of percutaneously implanted valve‐in‐valve in the tricuspid position for patients with pre‐existing transvalvular device leads.

Methods

In this case series, we describe implantation of the Melody valve and SAPIEN XT valve within dysfunctional bioprosthetic tricuspid valves in three patients with transvalvular device leads.

Results

In all cases, the valve was successfully deployed and device lead function remained unchanged. In 1/3 cases with 6‐month follow‐up, device lead parameters remain unchanged and transcatheter valve‐in‐valve function remains satisfactory.

Conclusions

Transcatheter tricuspid valve‐in‐valve is feasible in patients with pre‐existing transvalvular devices leads. Further study is required to determine the long‐term clinical implications of this treatment approach. © 2015 Wiley Periodicals, Inc.
Saccharose Inversion and Metastable Zone
Authors: Selbmann Stefanie , Herfurth Julia , Petersen Sandra , Ulrich Joachim
Published: May 2015

In the production of beverages, cookies, and candies, citric acid is often used as preservative or flavoring agent. Due to the sensitivity in stability of saccharose concerning pH and temperature, it is necessary to know how these two parameters affect the inversion of sugar and therefore the changes in the characteristics of saccharose crystallization. It can be shown that the inversion speed increases with increasing temperature. Also, the exposure time to the acid as well as the amount of acid lead to an increased inversion and therefore need to be controlled in industrial processes. With a temperature difference of 10 °C, inversion increases by the use of 2.13 % citric acid, e.g., by more than 250 %. The metastable zone shifts, but does not change in its width while inversion takes place and the solubility and nucleation curves are shifted to lower temperatures.
Solubility Characteristics and Crystallization Behavior of Oxalic Acid in the Presence of Sulfuric Acid
Authors: Imura Naoko , Hirasawa Izumi
Published: May 2015

Acidic wastewater from industrial discharge is generally treated by neutralization. Before neutralization or water treatment, selective recovery of valuable compounds is necessary to reduce the environmental impact of this acid waste. As a contribution to the development of a novel acidic wastewater treatment, oxalic acid is set as target material which is found in acid waste from the metalworking industry. Crystallization of oxalic acid in the presence of sulfuric acid has rarely been reported. Since this acid waste also contains aluminum ions, the effect of sulfuric acid and aluminum ions on oxalic acid solubility and crystallization was clarified. As a result, sulfuric acid concentration affected the oxalic acid solubility, but aluminum ions had no influence. Oxalic acid was precipitated in columnar shape by cooling crystallization from sulfuric acid aqueous solution with aluminum ions.
Polymorphism, Size and Shape Control of Calcium Carbonate Crystals in the Presence of a Polyelectrolyte
Authors: Sonobe Yuko , Watamura Hiroto , Hirasawa Izumi
Published: May 2015

The effects of the presence of a polyelectrolyte on the polymorphism and particle size and shape of calcium carbonate crystals during reactive crystallization were investigated. Crystals were created by the single‐jet reaction crystallization method. When polyacrylic acid (PAA) was added, the polymorphism and particle size and shape were different for each molecular weight of PAA and each experimental method. When sodium carboxymethylcellulose was added, the polymorph became different from those made by adding PAA and the particle sizes and shapes were different for each concentration. As a result, it is suggested that the method to achieve supersaturation, such as type of feeding, feed rate, kinds of polyelectrolyte and their concentration, may affect the polymorphism and particle size and shape of calcium carbonate.
Non‐Equimolar Discrete Phases Formed in the System of Malic Acid Enantiomers
Authors: Isakov Anton I. , Kotelnikova Elena N. , Lorenz Heike
Published: May 2015

X‐Ray diffractometry was employed to investigate the possibility of formation of non‐equimolar discrete compounds in the chiral system of malic acid S‐ and R‐enantiomers. Samples studied were mixtures of single enantiomers or an enantiomer and the various polymorphs of the racemic compound. From samples prepared via recrystallization of the melt and grinding of initial reactants, it is demonstrated that the malic acid enantiomers can form stable stoichiometric compounds in S:R ratios of 3:1 and 1:3. Compared to the known racemic and pure enantiomer phases, the corresponding compounds S3R/SR3 are characterized by a proper powder diffraction pattern and melting point.
Der Mensch, ein elektrisches Wesen
Authors: Kadenbach Bernhard
Published: May 2015

Unser Körper besteht aus Zellen, die, wie auch die Organellen im Innern der Zellen von einer biologischen Membran umgeben sind. Diese besteht aus einer Lipiddoppelschicht, die für den elektrischen Strom undurchlässig ist. Über den meisten Membranen lebender Zellen liegt eine elektrische Spannung, bzw. ein elektrochemisches Potential. Alle Lebensäußerungen des Menschen erfordern Energie, die vor allem durch das Molekül ATP bereitgestellt wird. Die chemische Energie im ATP stammt aus der “kalten Verbrennung” unserer Nährstoffe in den Mitochondrien, wobei intermediär ein elektrochemisches Potential an der Innenmembran der Mitochondrien entsteht. Die ATP‐Synthase nutzt die Energie dieses Potentials zur Bildung von ATP. Übersteigt die Spannung einen bestimmten Wert, so bilden sich schädliche Sauerstoffradikale. Hohe ATP‐Gehalte in Mitochondrien verhindern die Bildung der Sauerstoffradikale durch Hemmung der Cytochrom‐c‐Oxidase, dem letzten Glied der Zellatmung. Bei Stresssituationen des Organismus wird diese ATP‐Hemmung aufgehoben, wodurch die Spannung ansteigt und Sauerstoffradikale entstehen, die als Ursache für zahlreiche Krankheiten gelten.
Pilzragout nach Chemiker Art
Authors: Roth Klaus
Published: May 2015

Die Arbeitsgruppe von Wolfgang Steglich hat über viele Jahrzehnte die vielfältige Chemie der Höheren Pilze untersucht, in dem neue Inhaltsstoffe isoliert, deren Strukturen bestimmt und viele davon synthetisiert wurden. Sie entdeckten dabei neue heterozyklische Ringsysteme, wie die 2H‐Azepine und neue funktionelle Gruppen wie die Alkylazoxycarboxamides, von deren Existenz vorher niemand wusste. Die Höheren Pilze verdienen deswegen unsere ganze Wertschätzung nicht nur als eine besondere Delikatesse, sondern auch als besonders kreative Chemiker.
Isolation and characterization of living circulating tumor cells in patients by immunomagnetic negative enrichment coupled with flow cytometry
Authors: Lu Yusheng , Liang Haiyan , Yu Ting , Xie Jingjing , Chen Shuming , Dong Haiyan , Sinko Patrick J. , Lian Shu , Xu Jianguo , Wang Jichuang , Yu Suhong , Shao Jingwei , Yuan Bo , Wang Lie , Jia Lee
Published: May 2015

BACKGROUND

This study was aimed at establishing a sensitive and specific isolation, characterization, and enumeration method for living circulating tumor cells (CTCs) in patients with colorectal carcinoma.

METHODS

Quantitative isolation and characterization of CTCs were performed through a combination of immunomagnetic negative enrichment and fluorescence‐activated cell sorting. Isolated CTCs were identified by immunofluorescence staining. The viability and purity of the sorted cells were determined by flow cytometry. Blood samples spiked with HCT116 cells (range, 3‐250 cells) were used to determine specificity, recovery, and sensitivity. The method was used to enumerate, characterize, and isolate living CTCs in 10 mL of blood from patients with colorectal carcinoma.

RESULTS

The average recovery of HCT116 cells was 61% or more at each spiking level, and the correlation coefficient was 0.992. An analysis of samples from all 18 patients with colorectal carcinoma revealed that 94.4% were positive for CTCs with an average of 33 ± 24 CTCs per 10 mL of blood and with a diameter of 14 to 20 μm (vs 8‐12 μm for lymphoma). All patients were CD47+, with only 4.3% to 61.2% being CD44+. The number of CTCs was well correlated with the patient TNM stage and could be detected in patients at an early cancer stage. The sorted cells could be recultured, and their viability was preserved.

CONCLUSIONS

This method provides a novel technique for highly sensitive and specific detection and isolation of CTCs in patients with colorectal carcinoma. This method complements the existing approaches for the de novo functional identification of a wide variety of CTC types. It is likely to help in predicting a patient's disease progression and potentially in selecting the appropriate treatment. Cancer 2015;121:3036–3045. © 2015 American Cancer Society.
Crystal growth of FeCO3 in mixed monoethylene glycol and water solvent
Authors: Figueiredo Camila M. Senna , Junior Amaro G. Barreto , Flaten Ellen Marie , Beck Ralf , Seiersten Marion
Published: May 2015

The transportation of natural gas in long subsea pipelines is a challenge when it comes to hydrate prevention, corrosion and mineral scaling. When monoethylene glycol (MEG) is injected into carbon steel pipelines to prevent formation of gas hydrates, the solubility of the corrosion products is altered. Understanding the kinetics of FeCO3 precipitation may make it possible to avoid deposition in the gas liquid separation process and improve solids removal in MEG recovery units. In this work, the growth kinetics of iron carbonate (siderite) has been studied in seeded batch experiments in MEG‐water solutions with 0 and 40 wt% MEG at 50 and 70 °C. Precautions were taken to keep anaerobic conditions and avoid oxidation of ferrous ions. The growth rate (G) was measured as function of supersaturation (S) and fitted to the equation: G = kr(S‐1)g. The growth order (g) was approximately 2 independent of the MEG concentration at the two temperatures. The growth rate constant (kr) was in the range of 6 × 10−11 to 1 × 10−10 m/s. Temperature increase from 50 to 70°C had no measurable effect on the growth rate while in the presence of 40 wt% MEG the growth rate constant decreased.
Can human eyes prevent perceptual narrowing for monkey faces in human infants?
Authors: Damon Fabrice , Bayet Laurie , Quinn Paul C. , Hillairet de Boisferon Anne , Méary David , Dupierrix Eve , Lee Kang , Pascalis Olivier
Published: May 2015

Perceptual narrowing has been observed in human infants for monkey faces: 6‐month‐olds can discriminate between them, whereas older infants from 9 months of age display difficulty discriminating between them. The difficulty infants from 9 months have processing monkey faces has not been clearly identified. It could be due to the structural characteristics of monkey faces, particularly the key facial features that differ from human faces. The current study aimed to investigate whether the information conveyed by the eyes is of importance. We examined whether the presence of Caucasian human eyes in monkey faces allows recognition to be maintained in 6‐month‐olds and facilitates recognition in 9‐ and 12‐month‐olds. Our results revealed that the presence of human eyes in monkey faces maintains recognition for those faces at 6 months of age and partially facilitates recognition of those faces at 9 months of age, but not at 12 months of age. The findings are interpreted in the context of perceptual narrowing and suggest that the attenuation of processing of other‐species faces is not reversed by the presence of human eyes. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 57: 637–642, 2015.
Negative affect, interpersonal perception, and binge eating behavior: An experience sampling study
Authors: Ambwani Suman , Roche Michael J. , Minnick Alyssa M. , Pincus Aaron L.
Published: May 2015

Objective

Etiological and maintenance models for disordered eating highlight the salience of negative affect and interpersonal dysfunction. This study employed a 14‐day experience sampling procedure to assess the impact of negative affect and interpersonal perceptions on binge eating behavior.

Method

Young adult women (N = 40) with recurrent binge eating and significant clinical impairment recorded their mood, interpersonal behavior, and eating behaviors at six stratified semirandom intervals daily through the use of personal digital assistants.

Results

Although momentary negative affect was associated with binge eating behavior, average levels of negative affect over the experience sampling period were not, and interpersonal problems moderated the relationship between negative affect and binge eating. Interpersonal problems also intensified the association between momentary interpersonal perceptions and binge eating behavior. Lagged analyses indicated that previous levels of negative affect and interpersonal style also influence binge eating.

Discussion

The study findings suggest there may be important differences in how dispositional versus momentary experiences of negative affect are associated with binge eating. Results also highlight the importance of interpersonal problems for understanding relationships among negative affect, interpersonal perception, and binge eating behavior. These results offer several possibilities for attending to affective and interpersonal functioning in clinical practice. © 2015 Wiley Periodicals, Inc. (Int J Eat Disord 2015; 48:715–726)
State Feedback Control Using Particle Filter
Authors: NISHIDA TAKESHI
Published: May 2015

Since particle filters can be used in non‐Gaussian and nonlinear system models, they have a wider range of applications than Kalman filters. In this paper, a construction method for a state feedback control system using a particle filter as an observer for probabilistic state estimation is described. In order to assure robustness to non‐Gaussian noise, a maximum a‐posteriori probability estimation extraction method and an method for evaluation of the effective sample size have been incorporated into the particle filter. The effectiveness of the constructed system was verified experimentally, and the effectiveness of the state observer constructed with the particle filter is demonstrated through a comparison with a Kalman filter.