bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative imaging of red blood cell velocity invivo using optical coherence Doppler tomography
Authors: Ren Hugang , Du Congwu , Park Kicheon , Volkow Nora D. , Pan Yingtian
Published: June 2012

We present particle counting ultrahigh-resolution optical Doppler tomography (pc-μODT) that enables accurate imaging of red blood cell velocities (νRBC) of cerebrovascular networks by detecting the Doppler phase transients induced by the passage of a RBC through a capillary. We apply pc-μODT to image the response of capillary νRBC to mild hypercapnia in mouse cortex. The results show that νRBC in normocapnia (νN = 0.72 ± 0.15 mm/s) increased 36.1% ± 5.3% (νH = 0.98 ± 0.29 mm/s) in response to hypercapnia. Due to uncorrected angle effect and low hematocrit (e.g., ∼10%), νRBC directly measured by μODT were markedly underestimated (νN ≈ 0.27 ± 0.03 mm/s, νH ≈ 0.37± 0.05 mm/s). Nevertheless, the measured νRBC increase (35.3%) matched that (36.1% ± 5.3%) by pc-μODT.
Investigation on organic magnetoconductance based on polaron-bipolaron transition
Authors: Qin W. , Yin S. , Gao K. , Xie S. J.
Published: June 2012

We explore the magnetoconductance (MC) effect in an organic semiconductor device based on the magnetic field related bipolaron formation. We present the transition among spin-parallel spin-antiparallel polaron pairs and bipolarons with a group of dynamic equations. The transition rates are adjusted by the external magnetic field as well as the hyperfine interaction. By considering the mobility of polarons different from that of bipolarons, we obtain the MC in an organic semiconductor device. The theoretical calculation is well consistent to the experimental results. It is predicated that a maximum MC appears at a suitable branching ratio of bipolarons.
Capacitance-voltage analysis of high-carrier-density SrTiO3/GdTiO3 heterostructures
Authors: Jackson Clayton A. , Moetakef Pouya , James Allen S. , Stemmer Susanne
Published: June 2012

We report on capacitance-voltage (C-V) analysis of SrTiO3/GdTiO3 heterostructures that contain a high-density, two-dimensional electron gas (2DEG) at the interface. The complex admittance was measured as a function of frequency for different gate biases applied to a Schottky contact on the SrTiO3. A one-dimensional, complex impedance transmission line model was used to extract C-V characteristics from the frequency dependent admittance. The extracted capacitance was nearly independent of the gate voltage (up to −0.5 V), indicating a fully depleted SrTiO3 layer. The results are used to estimate the dielectric constant of the SrTiO3, the degree of modulation of the 2DEG by the maximum applied voltage (∼2.5%), and to establish an upper limit of the residual carrier density in the bulk of the SrTiO3 film (∼9 × 1018 cm−3).
Current-induced terahertz oscillations in plasmonic crystal
Authors: Kachorovskii V. Yu. , Shur M. S.
Published: June 2012

We discuss a possible mechanism of the current instability in multi-gated structures with periodic modulation of the electron density in the device channel. In such structures, the plasma wave velocity is periodically modulated as well, and the stationary electric current may become unstable with respect to generation of the plasma oscillations. In the simplest model of periodically alternating stripes of the electron density with plasma wave velocities sa and sb, respectively (sa < sb), the instability occurs when the electron drift velocity approaches sa. For typical parameters, the plasma oscillation frequency can be tuned to be in the terahertz range of frequencies.
Doping efficiency of phosphorus doped silicon nanocrystals embedded in a SiO2 matrix
Authors: Gutsch S. , Hartel A. M. , Hiller D. , Zakharov N. , Werner P. , Zacharias M.
Published: June 2012

Strongly size controlled silicon nanocrystals in silicon oxynitride matrix were prepared using plasma enhanced chemical vapor deposition following the superlattice approach. Doping was achieved by adding diluted phosphine as a precursor gas. Phosphorus quantification was done by secondary ion mass spectrometry. A model based on Poissonian distributions of interface defects and dopants is proposed to calculate the defects and the dopants per silicon nanocrystal as a function of phosphorus concentration. The model requires the comparison between the photoluminescence spectra from passivated and unpassivated samples. Finally, the doping efficiency of silicon nanocrystals embedded in silicon oxynitride is estimated to be >20%.
(LiFePO4-AC)/Li4Ti5O12 hybrid supercapacitor: The effect of LiFePO4 content on its performance
Authors: Chen Shuli , Hu Huachong , Wang Changqing , Wang Guiling , Yin Jinling , Cao Dianxue
Published: June 2012

Composites of LiFePO4 and activated carbon (LFP-AC) were prepared by a ball milling method. Their morphologies were investigated by scanning electronic microscopy and energy dispersive spectroscopy. Hybrid supercapacitors were assembled using the LFP-AC composites as the positive electrode and Li4Ti5O12 as the negative electrode (LFP-AC/Li4Ti5O12). Effects of the positive electrode composition (ratio of LiFePO4 to AC) on the performance of LFP-AC/Li4Ti5O12 were investigated via constant current charge-discharge tests. The results demonstrated that the specific capacity and the specific power of the LFP-AC/Li4Ti5O12 hybrid supercapacitor significantly depend upon the content of LiFePO4 in the LFP-AC positive electrode. At 0.5 A g−1 charge-discharge current, the specific capacity of the LFP-AC/Li4Ti5O12 with 30 wt. % LiFePO4 and 70 wt. % AC in the positive electrode is 42% higher than that of AC/Li4Ti5O12, and the two supercapacitors have the same specific power. After 500 charge-discharge cycles at 1.0 A g−1, the specific capacity of the LFP-AC/Li4Ti5O12 with 80 wt. % LiFePO4 and 20 wt. % AC in the positive electrode is 53% higher than that of AC/Li4Ti5O12. The hybrid device stores electric energy via both the double-layer electrostatic adsorption and the intercalation/deintercalation of lithium ions.
A new interferometry-based electron density fluctuation diagnostic on Alcator C-Mod
Authors: Kasten C. P. , Irby J. H. , Murray R. , White A. E. , Pace D. C.
Published: June 2012

The two-color interferometry diagnostic on the Alcator C-Mod tokamak has been upgraded to measure fluctuations in the electron density and density gradient for turbulence and transport studies. Diagnostic features and capabilities are described. In differential mode, fast phase demodulation electronics detect the relative phase change between ten adjacent, radially-separated (ΔR = 1.2 cm, adjustable), vertical-viewing chords, which allows for measurement of the line-integrated electron density gradient. The system can be configured to detect the absolute phase shift of each chord by comparison to a local oscillator, measuring the line-integrated density. Each chord is sensitive to density fluctuations with kR < 20.3 cm−1 and is digitized at up to 10 MS/s, resolving aspects of ion temperature gradient-driven modes and other long-wavelength turbulence. Data from C-Mod discharges is presented, including observations of the quasi-coherent mode in enhanced D-alpha H-mode plasmas and the weakly coherent mode in I-mode.
A two photon absorption laser induced fluorescence diagnostic for fusion plasmas
Authors: Magee R. M. , Galante M. E. , McCarren D. , Scime E. E. , Boivin R. L. , Brooks N. H. , Groebner R. J. , Hill D. N. , Porter G. D.
Published: June 2012

The quality of plasma produced in a magnetic confinement fusion device is influenced to a large extent by the neutral gas surrounding the plasma. The plasma is fueled by the ionization of neutrals, and charge exchange interactions between edge neutrals and plasma ions are a sink of energy and momentum. Here we describe a diagnostic capable of measuring the spatial distribution of neutral gas in a magnetically confined fusion plasma. A high intensity (5 MW/cm2), narrow bandwidth (0.1 cm−1) laser is injected into a hydrogen plasma to excite the Lyman β transition via the simultaneous absorption of two 205 nm photons. The absorption rate, determined by measurement of subsequent Balmer α emission, is proportional to the number of particles with a given velocity. Calibration is performed in situ by filling the chamber to a known pressure of neutral krypton and exciting a transition close in wavelength to that used in hydrogen. We present details of the calibration procedure, including a technique for identifying saturation broadening, measurements of the neutral density profile in a hydrogen helicon plasma, and discuss the application of the diagnostic to plasmas in the DIII-D tokamak.
Density fluctuation measurements by far-forward collective scattering in the MST reversed-field pinch
Authors: Ding W. X. , Lin L. , Duff J. R. , Brower D. L. , Sarff J. S.
Published: June 2012

The multichannel polarimeter-interferometer system on the MST reversed-field pinch can be utilized to measure far-forward collective scattering from electron density fluctuations. The collective scattering system has 11 viewing chords with ∼8 cm spacing. The source is a 432 μm (694 GHz) far infrared laser and the scattered power is measured using a heterodyne detection scheme. Collective scattering provides a line-integrated measurement of fluctuations within the divergence of the probe beam covering wavenumber range: k⊥ < 1.3 cm−1, corresponding k⊥ρs < 1.3 (ρs is the ion-sound Larmor radius), the region of primary interest for turbulent fluctuation-induced transport. The perpendicular wavenumber consists of toroidal, poloidal, and radial contributions, which vary with chord position. Coherent modes associated with tearing instabilities and neutral-beam driven fast particles are observed along with broadband turbulence at frequencies up to 500 kHz. Changes in frequency are consistent with a Doppler shift due to parallel plasma flow.
Conductivity and structure of ErAs nanoparticles embedded in GaAs pn junctions analyzed via conductive atomic force microscopy
Authors: Park K. W. , Dasika V. D. , Nair H. P. , Crook A. M. , Bank S. R. , Yu E. T.
Published: June 2012

We have used conductive atomic force microscopy to investigate the influence of growth temperature on local current flow in GaAs pn junctions with embedded ErAs nanoparticles grown by molecular beam epitaxy. Three sets of samples, one with 1 ML ErAs deposited at different growth temperatures and two grown at 530 °C and 575 °C with varying ErAs depositions, were characterized. Statistical analysis of local current images suggests that the structures grown at 575 °C have about 3 times thicker ErAs nanoparticles than structures grown at 530 °C, resulting in degradation of conductivity due to reduced ErAs coverage. These findings explain previous studies of macroscopic tunnel junctions.
Ultra-high speed photomultiplier tubes with nanosecond gating for fusion diagnostics
Authors: Milnes J. S. , Horsfield C. J. , Rubery M. S. , Glebov V. Yu. , Herrmann H. W.
Published: June 2012

Fusion diagnostics can involve the measurement of ultra-fast optical pulses, often in close temporal proximity. We present a solution for the diagnostics of gamma reaction history and neutron time of flight by using microchannel plate based photomultiplier tubes (PMTs). The time response of the PMTs can be as fast as 100 ps FWHM and with a gain of up to 107. To observe small events in close temporal proximity to much larger signals such as the down-scattered fraction, the response of MCP-PMTs can be gated with an on/off ratio of up to 1013 in just 2 ns.
Dynamic flexibility of the ATPase p97 is important for its interprotomer motion transmission
Authors: Huang Chengdong , Li Guangtao , Lennarz William J.
Published: June 2012

The hexameric protein p97, a very abundant type II AAA ATPase (ATPase associated with various cellular activities), is involved in a diverse range of cellular functions. During its ATPase cycle p97 functions as an ATP motor, converting the chemical energy released upon hydrolysis of ATP to ADP into mechanical work, which is then directed toward the proteins that serve as substrates. A key question in this process is: How is the nucleotide-induced motion transmitted from the C-terminal ATPase domain (the D2 domain) of p97 to the distant N-terminal substrate-processing domain? We have previously reported the surprising finding that motion transmission between the two ATPase domains (the D2 and D1 domains) is mediated by the D1-D2 linker region of its neighboring protomer. In this study we report efforts to better understand this process. Our findings suggest that the amino acid sequence containing Gly-Gly that is located at the C terminus of the D1-D2 linker functions as a pivoting point that allows the dynamic movement of the D1-D2 linker. Furthermore, we found that locking the D1-D2 linker to the D2 domain by introducing disulfide bonds significantly impaired the motion-transmission process. These results support our previous model for interprotomer motion transmission, and provide more detailed information on how the motion transmission between the two ATPase domains of p97 is relayed by the flexible movement of the D1-D2 linker from its neighboring protomer.
The organization of conspecific face space in nonhuman primates
Authors: Parr Lisa A. , Taubert Jessica , Little Anthony C. , Hancock Peter J. B.
Published: June 2012

Humans and chimpanzees demonstrate numerous cognitive specializations for processing faces, but comparative studies with monkeys suggest that these may be the result of recent evolutionary adaptations. The present study utilized the novel approach of face space, a powerful theoretical framework used to understand the representation of face identity in humans, to further explore species differences in face processing. According to the theory, faces are represented by vectors in a multidimensional space, the centre of which is defined by an average face. Each dimension codes features important for describing a face's identity, and vector length codes the feature's distinctiveness. Chimpanzees and rhesus monkeys discriminated male and female conspecifics’ faces, rated by humans for their distinctiveness, using a computerized task. Multidimensional scaling analyses showed that the organization of face space was similar between humans and chimpanzees. Distinctive faces had the longest vectors and were the easiest for chimpanzees to discriminate. In contrast, distinctiveness did not correlate with the performance of rhesus monkeys. The feature dimensions for each species’ face space were visualized and described using morphing techniques. These results confirm species differences in the perceptual representation of conspecific faces, which are discussed within an evolutionary framework.
The 2012 Plasma Roadmap
Authors: Samukawa Seiji , Hori Masaru , Rauf Shahid , Tachibana Kunihide , Bruggeman Peter , Kroesen Gerrit , Whitehead J Christopher , Murphy Anthony B , Gutsol Alexander F , Starikovskaia Svetlana , Kortshagen Uwe , Boeuf Jean-Pierre , Sommerer Timothy J , Kushner Mark J , Czarnetzki Uwe , Mason Nigel
Published: June 2012

Low-temperature plasma physics and technology are diverse and interdisciplinary fields. The plasma parameters can span many orders of magnitude and applications are found in quite different areas of daily life and industrial production. As a consequence, the trends in research, science and technology are difficult to follow and it is not easy to identify the major challenges of the field and their many sub-fields. Even for experts the road to the future is sometimes lost in the mist. Journal of Physics D: Applied Physics is addressing this need for clarity and thus providing guidance to the field by this special Review article, The 2012 Plasma Roadmap.

Although roadmaps are common in the microelectronic industry and other fields of research and development, constructing a roadmap for the field of low-temperature plasmas is perhaps a unique undertaking. Realizing the difficulty of this task for any individual, the plasma section of the Journal of Physics D Board decided to meet the challenge of developing a roadmap through an unusual and novel concept. The roadmap was divided into 16 formalized short subsections each addressing a particular key topic. For each topic a renowned expert in the sub-field was invited to express his/her individual visions on the status, current and future challenges, and to identify advances in science and technology required to meet these challenges.

Together these contributions form a detailed snapshot of the current state of the art which clearly shows the lifelines of the field and the challenges ahead. Novel technologies, fresh ideas and concepts, and new applications discussed by our authors demonstrate that the road to the future is wide and far reaching. We hope that this special plasma science and technology roadmap will provide guidance for colleagues, funding agencies and government institutions. If successful in doing so, the roadmap will be periodically updated to continue to help in guiding the field.
Magnonic band gap design by the edge modulation of micro-sized waveguides
Authors: Ciubotaru F , Chumak A V , Yu Grigoryeva N , Serga A A , Hillebrands B
Published: June 2012

The potential to control the number of the spin-wave band gaps of a magnonic crystal (MC) by variation of its geometry is investigated by numerical simulations. The MC is represented by a micro-sized planar ferromagnetic waveguide with periodically variable width. By choosing a step-like or sinusoidal variation of the width, the MC reveals multiple or single band gaps, respectively. This allows for additional degrees of freedom in the design of MC-based microwave filters and phase shifters with desired characteristics. The MCs' band gaps have been studied in the space and frequency domains exploring the spin-wave spectrum dependence on the probing position inside the MC.
Avoiding fatal damage to the top electrodes when forming unipolar resistance switching in nano-thick material systems
Authors: Lee S B , Kwon D-H , Kim K , Yoo H K , Sinn S , Kim M , Kahng B , Kang B S
Published: June 2012

When forming unipolar resistance switching in material systems, fatal damage often occurs to the top electrodes of Pt/SrTiO
x
/Pt, Pt/TiO
y
/Pt and Pt/NiO
z
/Pt cells. To develop a means of overcoming this problem, we systematically investigated the forming process by applying triangular- and pulse-waveform voltage signals to the cells. By investigating the dependence on sweep rate of the triangular-waveform voltage signals and amplitude of the pulse-waveform voltage signals, we discovered that the forming process occurred by two different mechanisms, irrespective of the material: either a thermally assisted dielectric breakdown or a purely electrical dielectric breakdown. During the former process, the top electrodes remained clean, even though oxygen bubbles formed on them. We observed that the top electrodes were blown off only for the latter (electrical) breakdown as a result of the formation of many conducting channels. We were able to overcome the fatal damage to the top electrodes by modifying the forming process into the thermally assisted dielectric breakdown.
Plasmas in saline solutions sustained using rectified ac voltages: polarity and frequency effects on the discharge behaviour
Authors: Chang Hung-wen , Hsu Cheng-che
Published: June 2012

In this work, three major problems, namely severe electrode damage, poor plasma stability and excess power consumption, arising in ac-driven plasmas in saline solutions are solved using a rectified power source. Diagnostic studies on the effects of power source polarity and frequency on the plasma behaviour are performed. Examination of I–V characteristics and temporally resolved light emission shows that the polarity significantly influences the current amplitude when the plasma exists, while the frequency alters the bubble dynamics, which in turn affects the plasma ignition voltage. When the plasma is driven by a rectified ac power source, the electrode erosion is reduced substantially. With a low frequency, moderate applied voltage and positively rectified ac power source (e.g. 100 Hz and 350 V), a stable plasma is ignited in nearly every power cycle.
Response of a manganite-based magnetic tunnel structure to microwave radiation
Authors: Volkov N V , Rautskiy M V , Eremin E V , Patrin G S , Kim P D , Lee C G
Published: June 2012

We demonstrate that a magnetic tunnel structure irradiated by microwaves can generate a typical voltage signal due to the rectification effect. We performed measurements in current-in-plane geometry when a current flows parallel to the interfaces in the structure. The value of the microwave-induced voltage strongly depends on the bias current and can be driven by a magnetic field. The rectification effect is discussed both in classical terms of nonlinearity of the current–voltage characteristics and within the mechanism involving the interplay between the spin-polarized current and the magnetization dynamics in the magnetic tunnel structure.
Long-range Rydberg–Rydberg interactions in calcium, strontium and ytterbium
Authors: Vaillant C L , Jones M P A , Potvliege R M
Published: June 2012

Long-range dipole–dipole and quadrupole–quadrupole interactions between pairs of Rydberg atoms are calculated perturbatively for calcium, strontium and ytterbium within the Coulomb approximation. Quantum defects, obtained by fitting existing laser spectroscopic data, are provided for all S, P, D and F series of strontium and for the 3P2 series of calcium. The results show qualitative differences with the alkali metal atoms, including isotropically attractive interactions of the strontium 1S0 states and a greater rarity of Förster resonances. Only two such resonances are identified, both in triplet series of strontium. The angular dependence of the long-range interaction is briefly discussed.
Convergence of refinement schemes on metric spaces
Authors: Ebner Oliver
Published: June 2012

We analyze the convergence of iterative refinement processes on metric spaces, imposing the principle of contractivity to obtain convergence criteria. As a major result, we show that on Hadamard spaces a wide natural class of contractible barycentric subdivision schemes converges.
Hilbert space compression under direct limits and certain group extensions
Authors: Dreesen Dennis
Published: June 2012

We find bounds on the Hilbert space compression exponent of the limit of a directed metric system of groups. We also give estimates on the Hilbert space compression exponent of a group extension of a group

H
H

by a word-hyperbolic group or a group of polynomial growth.
Cot/tpl2-MKK1/2-Erk1/2 controls mTORC1-mediated mRNA translation in Toll-like receptor–activated macrophages
Authors: López-Pelaéz Marta , Fumagalli Stefano , Sanz Carlos , Herrero Clara , Guerra Susana , Fernandez Margarita , Alemany Susana
Published: June 2012

Cot/tpl2 is the only MAP3K that activates MKK1/2-Erk1/2 in Toll-like receptor–activated macrophages. Here we show that Cot/tpl2 regulates RSK, S6 ribosomal protein, and 4E-BP phosphorylation after stimulation of bone marrow–derived macrophages with lipopolysaccharide (LPS), poly I:C, or zymosan. The dissociation of the 4E-BP–eIF4E complex, a key event in the cap-dependent mRNA translation initiation, is dramatically reduced in LPS-stimulated Cot/tpl2-knockout (KO) macrophages versus LPS-stimulated wild-type (Wt) macrophages. Accordingly, after LPS activation, increased cap-dependent translation is observed in Wt macrophages but not in Cot/tpl2 KO macrophages. In agreement with these data, Cot/tpl2 increases the polysomal recruitment of the 5´ TOP eEF1α and eEF2 mRNAs, as well as of inflammatory mediator gene–encoding mRNAs, such as tumor necrosis factor α (TNFα), interleukin-6 (IL-6), and KC in LPS-stimulated macrophages. In addition, Cot/tpl2 deficiency also reduces total TNFα, IL-6, and KC mRNA expression in LPS-stimulated macrophages, which is concomitant with a decrease in their mRNA half-lives. Macrophages require rapid fine control of translation to provide an accurate and not self-damaging response to host infection, and our data show that Cot/tpl2 controls inflammatory mediator gene–encoding mRNA translation in Toll-like receptor–activated macrophages.
Neural sensitivity to sex steroids predicts individual differences in aggression: implications for behavioural evolution
Authors: Rosvall K. A. , Bergeon Burns C. M. , Barske J. , Goodson J. L. , Schlinger B. A. , Sengelaub D. R. , Ketterson E. D.
Published: June 2012

Testosterone (T) regulates many traits related to fitness, including aggression. However, individual variation in aggressiveness does not always relate to circulating T, suggesting that behavioural variation may be more closely related to neural sensitivity to steroids, though this issue remains unresolved. To assess the relative importance of circulating T and neural steroid sensitivity in predicting behaviour, we measured aggressiveness during staged intrusions in free-living male and female dark-eyed juncos (
Junco hyemalis
). We compared aggressiveness to plasma T levels and to the abundance of androgen receptor (AR), aromatase (AROM) and oestrogen receptor alpha (ORα) mRNA in behaviourally relevant brain areas (avian medial amygdala, hypothalamus and song control regions). We also asked whether patterns of covariation among behaviour and endocrine parameters differed in males and females, anticipating that circulating T may be a better predictor of behaviour in males than in females. We found that circulating T related to aggressiveness only in males, but that gene expression for ORα, AR and AROM covaried with individual differences in aggressiveness in both sexes. These findings are among the first to show that individual variation in neural gene expression for three major sex steroid-processing molecules predicts individual variation in aggressiveness in both sexes in nature. The results have broad implications for our understanding of the mechanisms by which aggressive behaviour may evolve.
Differences in neutralizing antigenicity between laboratory and clinical isolates of HCoV-229E isolated in Japan in 2004–2008 depend on the S1 region sequence of the spike protein
Authors: Shirato Kazuya , Kawase Miyuki , Watanabe Oshi , Hirokawa Chika , Matsuyama Shutoku , Nishimura Hidekazu , Taguchi Fumihiro
Published: June 2012

Human coronavirus (HCoV) is a causative agent of the common cold. Although HCoV is highly prevalent in the world, studies of the genomic and antigenic details of circulating HCoV strains have been limited. In this study, we compared four Japanese isolates with the standard HCoV-229E strain obtained from ATCC (ATCC-VR740) by focusing on the spike (S) protein, a major determinant of neutralizing antigen and pathogenicity. The isolates were found to have nucleotide deletions and a number of sequence differences in the S1 region of the S protein. We compared two of the Japanese isolates with the ATCC-VR740 strain by using virus-neutralizing assays consisting of infectious HCoV-229E particles and vesicular stomatitis virus (VSV)-pseudotyped virus carrying the HCoV-229E S protein. The two clinical isolates (Sendai-H/1121/04 and Niigata/01/08) did not react with antiserum to the ATCC-VR740 strain via the neutralizing test. We then constructed a pseudotype VSV-harboured chimeric S protein with the ATCC S1 and Sendai S2 regions or that with Sendai S1 and ATCC S2 regions and compared them by a neutralization test. The results revealed that the difference in the neutralizing antigenicity depends on the S1 region. This different antigenic phenotype was also confirmed by a neutralizing test with clinically isolated human sera. These results suggest that the HCoV-229E viruses prevalent in Japan are quite different from the laboratory strain ATCC-VR740 in terms of the S sequence and neutralization antigenicity, which is attributed to the difference in the S1 region.
Organ tropism of murine coronavirus does not correlate with the expression levels of the membrane-anchored or secreted isoforms of the carcinoembryonic antigen-related cell adhesion molecule 1 receptor
Authors: Slobodskaya Olga , Snijder Eric J. , Spaan Willy J. M.
Published: June 2012

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is the sole known receptor of murine hepatitis virus (MHV) A59, but the available, often qualitative, data about CEACAM1 expression does not explain MHV organ tropism. Ceacam1 transcripts undergo alternative splicing resulting in multiple isoforms, including secreted CEACAM1 isoforms that can neutralize the virus. We determined the quantities of Ceacam1 transcripts encoding membrane-bound and secreted isoforms in mouse organs and a set of cell lines. In vivo, the lowest receptor mRNA levels were found in brain and muscle and these were similar to those in easily infectable cultured cells. While the quantities of the receptor transcripts varied between mouse organs, their abundance did not correlate with susceptibility to MHV infection. The proportion of transcripts encoding secreted isoforms also could not explain the selection of sites for virus replication, as it was constant in all organs. Our data suggest that neither of the two CEACAM1 isoforms defines MHV organ tropism.
Construction of an infectious Chikungunya virus cDNA clone and stable insertion of mCherry reporter genes at two different sites
Authors: Kümmerer Beate Mareike , Grywna Klaus , Gläsker Sabine , Wieseler Janett , Drosten Christian
Published: June 2012

Chikungunya virus (CHIKV) has caused massive epidemics in the Indian Ocean region since 2005. It belongs to the genus Alphavirus and possesses a positive-stranded RNA genome of nearly 12 kb in size. To produce genetically modified viruses for the study of various aspects of the CHIKV life cycle, a reverse genetic system is needed. We report the generation of a T7 RNA polymerase-driven infectious cDNA clone of CHIKV. Electroporation of in vitro-transcribed RNA resulted in the recovery of a recombinant virus with growth characteristics comparable to the parental strain. Using the established cDNA clone, the red fluorescent marker gene mCherry was introduced into two different sites within the CHIKV nsP3 gene. Both constructs allowed the rescue of stable fluorescent reporter viruses with growth characteristics similar to the wild-type virus. The latter reporter viruses represent valuable tools for easy follow-up of replicating CHIKV useful in several applications of CHIKV research.
In vivo imaging of proteasome inhibition using a proteasome‐sensitive fluorescent reporter
Authors: Momose Isao , Tatsuda Daisuke , Ohba Shun‐ichi , Masuda Tohru , Ikeda Daishiro , Nomoto Akio
Published: June 2012

A proteasome degrades numerous regulatory proteins that are critical for tumor growth and is therefore recognized as a promising anticancer target. Determining proteasome activity in the tumors of mice bearing xenografts is essential for the development of novel proteasome inhibitors. We developed a system for in vivo imaging of proteasome inhibition in the tumors of living mice, using a proteasome‐sensitive fluorescent reporter, ZsProSensor‐1. This reporter consists of a green fluorescent protein, ZsGreen, fused to mouse ornithine decarboxylase, which is degraded by the proteasome without being ubiquitinated. In stably transfected cells expressing ZsProSensor‐1, the fluorescent reporter was rapidly degraded under steady‐state conditions, whereas it was stabilized in the presence of proteasome inhibitors. Subcutaneous inoculation of the transfected cells into nude mice resulted in tumor formation. When the proteasome inhibitor bortezomib was intravenously administered to mice bearing these tumors, the ZsProSensor‐1 protein accumulated in the tumors and emitted a fluorescent signal in a dose‐dependent manner. Robust fluorescence was sustained for 3 days and then gradually decreased to baseline levels within 15 days. Intravenous administration of bortezomib also showed potent antitumor activity. In contrast, oral administration of bortezomib did not result in fluorescent protein accumulation in tumors or exhibit any antitumor activity. These results indicate that in vivo imaging using the ZsProSensor‐1 fluorescent protein can be used as an indicator of antitumor activity and will be a powerful tool for the development of novel proteasome inhibitors.
Randomized phase II study of three doses of oral TAS‐108 in postmenopausal patients with metastatic breast cancer
Authors: Inaji Hideo , Iwata Hiroji , Nakayama Takahiro , Yamamoto Naohito , Sato Yasuyuki , Tokuda Yutaka , Aogi Kenjiro , Saji Shigehira , Watanabe Kenichi , Saito Tsuyoshi , Yoshida Masayuki , Sato Nobuaki , Saeki Toshiaki , Takatsuka Yuichi , Kuranami Masaru , Yamashita Hiroko , Kikuchi Atsushi , Tabei Toshio , Ikeda Tadashi , Noguchi Shinzaburo
Published: June 2012

This randomized phase II study was intended to identify the optimal dose of TAS‐108, a novel steroidal antiestrogen, for the treatment of breast cancer in postmenopausal Japanese women. The potential clinical effects of TAS‐108 on the uterus, bone, serum lipids, and hormones were also investigated. Postmenopausal women with hormone receptor‐positive metastatic breast cancer who had previously received one or two endocrine therapies were randomly assigned to one of the three possible dose levels of TAS‐108 (40, 80 or 120 mg/day). Oral TAS‐108 was given daily, and the efficacy and safety of the three doses were evaluated. A total of 97 patients (33, 32, and 32 in the 40‐, 80‐, and 120‐mg groups, respectively) were treated with TAS‐108. The clinical benefit rate was 30.3% for the 40‐mg, 25.0% for the 80‐mg, and 25.0% for the 120‐mg group. The 40‐mg group achieved the prespecified target threshold. TAS‐108 at all dose levels was well tolerated and appeared to have no harmful effects in terms of the variables examined in this study. We conclude that the optimal dose of TAS‐108 among the three doses is 40 mg, once daily, for further studies. JAPIC Clinical Trials Information number: Japic CTI – 121754.
Cancer‐testis antigen BORIS is a novel prognostic marker for patients with esophageal cancer
Authors: Okabayashi Koji , Fujita Tomonobu , Miyazaki Junichiro , Okada Tsutomu , Iwata Takashi , Hirao Nobumaru , Noji Shinobu , Tsukamoto Nobuo , Goshima Naoki , Hasegawa Hirotoshi , Takeuchi Hiroya , Ueda Masakazu , Kitagawa Yuko , Kawakami Yutaka
Published: June 2012

Esophageal squamous cell cancer (ESCC) is one of the most common lethal tumors in the world, and development of new diagnostic and therapeutic methods is needed. In this study, cancer‐testis antigen, BORIS, was isolated by functional cDNA expression cloning using screening technique with serum IgG Abs from ESCC patients. BORIS was previously reported to show cancer‐testis antigen like expression, but its immunogenicity has remained unclear in cancer patients. BORIS was considered to be an immunogenic antigen capable of inducing IgG Abs in patients with various cancers, including four of 11 ESCC patients. Immunohistochemical study showed that the BORIS protein was expressed in 28 of 50 (56%) ESCC tissues. The BORIS expression was significantly associated with lymph node metastasis in ESCC patients with pT1 disease (P = 0.036). Furthermore, the patients with BORIS‐positive tumors had a poor overall survival (5‐year survival rate: BORIS‐negative 70.0% vs BORIS‐positive 29.9%, log‐rank P = 0.028) in Kaplan–Meier survival analysis and log‐rank test. Multivariate Cox proportional hazard model demonstrated that BORIS expression was an independent poor prognostic factor (hazard ratio = 4.158 [95% confidence interval 1.494–11.57], P = 0.006). Downregulation of BORIS with specific siRNAs resulted in decreased cell proliferation and invasion ability of ESCC cell lines. BORIS may be a useful biomarker for prognostic diagnosis of ESCC patients and a potential target for treatment including by BORIS‐specific immunotherapy and molecular target therapy.
Potentially curative treatment in patients with hepatocellular cancer—results from the liver cancer research network
Authors: Kanwal F. , Befeler A. , Chari R. S. , Marrero J. , Kahn J. , Afdhal N. , Morgan T. , Roberts L. , Mohanty S. R. , Schwartz J. , VanThiel D. , Li J. , Zeringue A. , Di'Bisceglie A.
Published: June 2012

Background

The extent to which potentially curative therapies are used in patients with hepatocellular cancer (HCC) and their related outcomes are unknown in the US.

Aim

To determine the rate and outcomes of potentially curative treatment in patients with HCC.

Methods

Eleven US centers followed patients with HCC between 2001 and 2007. We determined rates of liver transplantation, surgical resection, or tumour ablation during follow‐up, examined differences in adjusted survival of patients receiving these treatments, and determined the factors associated with receipt of potentially curative treatment.

Results

Of the 267 patients, 76 (28%) patients had early HCC, defined as Child A or B cirrhosis, with a solitary HCC or ≤3 nodules, each ≤3 cm. Of these, 53 (69.7%) received curative treatment. Thirty six percent of patients with non‐early HCC received curative treatment. Compared to patients with non‐early HCC who did not receive curative treatment, patients with early HCC and curative treatment had the best survival [hazard ratio, HR = 0.19 (95% CI, 0.08–0.42)] followed by patients with advanced HCC who received curative treatment [HR = 0.37 (95% CI, 0.22–0.64)]. Baseline performance status was significantly associated with receipt of curative treatment as well as survival after adjusting for demographics, clinical characteristics, and HCC stage.

Conclusions

In this multicenter database, most of the patients with early HCC received potentially curative treatment. However, only 28% of patients had early HCC. One‐third of patients with non‐early HCC also underwent curative therapy. Potentially curative treatment improved survival and this effect was seen in patients with early as well as non‐early HCC.
Ursodeoxycholic acid therapy in cystic fibrosis liver disease – a retrospective long‐term follow‐up case‐control study
Authors: Kappler M. , Espach C. , Schweiger‐Kabesch A. , Lang T. , Hartl D. , Hector A. , Glasmacher C. , Griese M.
Published: June 2012

Background

The prevention and treatment of liver disease associated with cystic fibrosis remain a significant unresolved problem.

Aim

To assess the long‐term effects of continuous ursodeoxycholic acid (UDCA) therapy in cystic fibrosis patients with constantly elevated serum liver enzymes.

Methods

The primary endpoint was the incidence of overt liver disease. Between 1989 and 2005, UDCA treatment was started in 98 subjects from a cohort of 382 cystic fibrosis patients. These subjects were compared with a historic control group of 352 subjects who attended our centre between 1975 and 1989 before UDCA became standard treatment. For the long‐term comparison of liver function and lung function tests, a group of 98 matched contemporary cystic fibrosis patients were compared with the 98 subjects treated with UDCA.

Results

Overt liver disease developed in only one of the 382 patients who was treated with UDCA for increased serum liver enzymes compared with nine patients in the historic control group (P < 0.05). Serum liver enzyme levels declined in most patients receiving UDCA treatment during the 17‐year follow‐up (87/98, P < 0.05). No difference was seen in lung function between subjects with cystic fibrosis‐related liver disease and the matched controls.

Conclusions

Regular and systematic screening for liver involvement enables early introduction of UDCA therapy in affected cystic fibrosis patients, reduces the development of severe liver disease and leads to a significant and persistent improvement in serum liver tests, without impairing long‐term pulmonary outcome.
Identification of single nucleotide polymorphisms in the bovine follicle‐stimulating hormone receptor and effects of genotypes on superovulatory response traits
Authors: Cory Aron T. , Price Christopher A. , Lefebvre Rejean , Palin Marie‐France
Published: June 2012

In dairy cows, there is evidence that failure to respond to superovulation protocols is a heritable trait. In women, genotyping for the p.N680S single nucleotide polymorphism (SNP) in the follicle‐stimulating hormone receptor (FSHR) gene may help identify poor responders before ovarian stimulation is initiated. Our objectives were to identify SNPs in the coding region of the bovine FSHR gene and to investigate the effect of FSHR genotypes on superovulatory response in Holstein cattle. Sequencing of FSHR exons 1–10 revealed seven SNPs. Three were non‐synonymous mutations (c.337C>G, c.871A>G and c.1973C>G). SNP c.337C>G encodes for a proline‐to‐alanine (p.Pro113Ala) amino acid replacement in the extracellular ligand‐binding domain of the receptor. PCR‐RFLP analyses showed that homozygous GG Holstein cows present a higher percentage of viable embryos, whereas GG and CG animals have less unfertilised oocytes. SNP c.871A>G results in an isoleucine‐to‐valine (p.Ile291Val) modification, and homozygous AA animals present lower embryo yield after superovulatory treatments. SNP c.1973C>G corresponds to a threonine‐to‐serine (p.The658Ser) modification in the intracellular carboxyl‐terminal domain of the FSHR protein, and homozygous GG Holstein cows were associated with a lower embryo yield and a higher percentage of unfertilised oocytes. Our results suggest that specific alleles of the bovine FSHR gene are associated with variations in embryo yield and in the number of unfertilised oocytes.
Dynamic macroecology and the future for biodiversity
Authors: Mokany Karel , Harwood Thomas D. , Williams Kristen J. , Ferrier Simon
Published: June 2012

Reliable projections of climate‐change impacts on biodiversity are vital in formulating conservation and management strategies that best retain biodiversity into the future. While recent modelling has focussed largely on individual species, macroecology has the potential to add significant value to these efforts, by incorporating important community‐level constraints and processes. Here we show how a new dynamic macroecological approach can project climate‐change impacts collectively across all species in a diverse taxonomic group, overcoming shortfalls in our knowledge of biodiversity, while incorporating the key processes of dispersal and community assembly. Our approach applies a recently published technique (DynamicFOAM) to predict the present composition of every community, which form the initial conditions for a new metacommunity model (M‐SET) that projects changes in composition over time, under specified climate and habitat scenarios. Applying this approach at fine resolution to plant biodiversity in Tasmania (2,051 species; 1,157,587 communities), we project high average turnover in community composition from 2010 to 2100 (mean Sorensen's dissimilarity = 0.71 (±7.0 × 10−5)), with major reductions in species richness (32.9 (±0.02) species lost per community) and no plant species benefitting from climate change in the long term. We also demonstrate how our modelling approach can identify habitat likely to be of high value for retaining rare and poorly reserved species under climate change. Our analyses highlight the potential value of this dynamic macroecological approach, that incorporates key ecological processes in projecting climate change impacts for all species simultaneously and uses simple macroecological inputs that can be derived even for highly diverse and poorly studied taxa.
The (dis)placement of women in the IT workforce: an investigation of individual career values and organisational interventions
Authors: Quesenberry Jeria L , Trauth Eileen M
Published: June 2012

This paper reports on an investigation of career anchors of women in the information technology (IT) workforce that was directed at enhancing within‐gender theorising about career motivations of women in the IT profession. Our theoretical lens, the individual differences theory of gender and IT, enabled us to look more critically at how the effects of interventions are embedded in the range of women's career anchors that takes within‐gender variation into account. The analysis demonstrates that organisational interventions must be flexible enough to account for the diversity and variation among women. Further, the analysis shows that it is necessary to move away from ‘one size fits all’ organisational interventions that often reflect stereotypes about women in the IT workforce.
Factors influencing burden among non‐professional immigrant caregivers: a case–control study
Authors: Gallart Albert , Cruz Félix , Zabalegui Adelaida
Published: June 2012

gallart a., cruz f. & zabalegui a. (2013) Factors influencing burden among non‐professional immigrant caregivers: a case–control study. Journal of Advanced Nursing69(3), 642–654. doi: 10.1111/j.1365‐2648.2012.06049.x

Aim.  To identify factors related to the burden that is experienced by untrained immigrant caregivers.

Background.  There is growing concern about how to provide the care required by an ageing population. Although elder care has usually been provided by family members, this role is increasingly being fulfilled by immigrant caregivers with no formal training.

Design.  Case–control study (burdened/non‐burdened according to the Zarit Burden Interview).

Methods.  The study took place between May 2005–October 2009. Anonymous questionnaires were distributed to 110 immigrant caregivers and their corresponding older care recipients (n = 110), who were receiving care in their homes in Barcelona (Spain). The questionnaires included measures of burden, social support, quality of life and social integration, and items about the physical/psychological status of the care recipient and the nature of the care tasks. Two groups of immigrant caregivers were defined according to their scores on the Zarit Burden Interview: burdened (n = 55) and non‐burdened (n = 55).

Results.  Burdened caregivers reported less social support, a poorer quality of life, and problems with social integration. Furthermore, 48% said that they lacked knowledge about the care task, while 44% had difficulty performing certain care tasks, which constitutes a risk situation.

Conclusion.  Burden among untrained immigrant caregivers may be reduced by improving their social support systems and quality of life, thereby helping to ensure the availability of the caregiver services, which society increasingly needs.
Control in childbirth: a concept analysis and synthesis
Authors: Meyer Shaunette
Published: June 2012

Aim.  To report a concept analysis of control in childbirth.

Background.  Control has a variety of definitions from a wide range of disciplines. In childbirth, however, the concept is more tenuous and depends on the context. It can be viewed in relationship to a woman’s body and labour progression, pain, environment and the ability to request her method of birth.

Data sources.  Medline, CINAHL and PsycINFO databases were searched between 1970–2011 using the keywords, ‘control’, ‘childbirth’, ‘labour’ and ‘delivery’.

Review methods.  Walker and Avant’s method of concept analysis was used for this review. In addition, cases were placed before defining attributes as recommended by Risjord.

Results.  Four attributes of control were identified: decision‐making, access to information, personal security and physical functioning. Antecedents include pregnancy and expectations of the birth. Consequences include childbirth satisfaction, childbirth experience, emotional well‐being, fulfilment and the transition into motherhood. A model case, contrary case and borderline case are described.

Conclusion.  Clarifying the definition of control in childbirth and defining its attributes can help inform women and maternity providers throughout the world. This analysis provides clarity to a previously tenuous concept and allows practitioners to better understand the critical relationship between control in childbirth and satisfaction with the childbirth experience. It also has the potential to affect perinatal outcomes and subsequently healthcare costs.