bluuebunny/crossref_metadata_2025 huggingface dataset:
Flow at ice‐divide triple junctions: 2. Three‐dimensional views of isochrone architecture from ice‐penetrating radar surveys
Authors: Hindmarsh Richard C. A. , King Edward C. , Mulvaney Robert , Corr Hugh F. J. , Hiess Gisela , Gillet‐Chaulet Fabien
Published: June 2011

Ground‐based surveys of ice‐divide triple junctions in two Antarctic ice rises, the Fletcher Promontory and Berkner Island, have been carried out using low‐frequency ice‐penetrating radars. These surveys have focused on understanding the internal layer architecture at and around the triple junctions, with a particular emphasis on understanding how the Raymond effect operates. A variety of features have been observed, including Raymond cupolas under the junctions, bump stacks of varying amplitude with distance from the divide, double bumps, crooked stacks implying divide motion, and the presence of ridges containing weak and strong bump stacks. It was generally not possible to elucidate the three‐dimensional structure by correlation of pick crossovers, so instead a least squares cross‐correlation technique was used which computes nominal age surfaces using radial basis function interpolation. Double bumps are absent from the central cupola of Fletcher Promontory, permitting us to infer that the ice here has thinned by around 500 m in the past 5000 years. Estimates of the age scale suggest that there will be recoverable Eemian ice. A technique for inferring the velocity profile at divides using layer traces and assumed velocities in the flanks is presented.
The deglacial transition on the southeastern Alaska Margin: Meltwater input, sea level rise, marine productivity, and sedimentary anoxia
Authors: Davies M. H. , Mix A. C. , Stoner J. S. , Addison J. A. , Jaeger J. , Finney B. , Wiest J.
Published: June 2011

Oxygen isotope data from planktonic and benthic foraminifera, on a high‐resolution age model (44 14C dates spanning 17,400 years), document deglacial environmental change on the southeast Alaska margin (59°33.32′N, 144°9.21′W, 682 m water depth). Surface freshening (i.e., δ18O reduction of 0.8‰) began at 16,650 ± 170 cal years B.P. during an interval of ice proximal sedimentation, likely due to freshwater input from melting glaciers. A sharp transition to laminated hemipelagic sediments constrains retreat of regional outlet glaciers onto land circa 14,790 ± 380 cal years B.P. Abrupt warming and/or freshening of the surface ocean (i.e., additional δ18O reduction of 0.9‰) coincides with the Bølling Interstade of northern Europe and Greenland. Cooling and/or higher salinities returned during the Allerød interval, coincident with the Antarctic Cold Reversal, and continue until 11,740 ± 200 cal years B.P., when onset of warming coincides with the end of the Younger Dryas. An abrupt 1‰ reduction in benthic δ18O at 14,250 ± 290 cal years B.P. likely reflects a decrease in bottom water salinity driven by deep mixing of glacial meltwater, a regional megaflood event, or brine formation associated with sea ice. Two laminated opal‐rich intervals record discrete episodes of high productivity during the last deglaciation. These events, precisely dated here at 14,790 ± 380 to 12,990 ± 190 cal years B.P. and 11,160 ± 130 to 10,750 ± 220 cal years B.P., likely correlate to similar features observed elsewhere on the margins of the North Pacific and are coeval with episodes of rapid sea level rise. Remobilization of iron from newly inundated continental shelves may have helped to fuel these episodes of elevated primary productivity and sedimentary anoxia.
Fibroblast growth factors and their receptors in cancer
Authors: Wesche Jørgen , Haglund Kaisa , Haugsten Ellen Margrethe
Published: June 2011

FGFs (fibroblast growth factors) and their receptors (FGFRs) play essential roles in tightly regulating cell proliferation, survival, migration and differentiation during development and adult life. Deregulation of FGFR signalling, on the other hand, has been associated with many developmental syndromes, and with human cancer. In cancer, FGFRs have been found to become overactivated by several mechanisms, including gene amplification, chromosomal translocation and mutations. FGFR alterations are detected in a variety of human cancers, such as breast, bladder, prostate, endometrial and lung cancers, as well as haematological malignancies. Accumulating evidence indicates that FGFs and FGFRs may act in an oncogenic fashion to promote multiple steps of cancer progression by inducing mitogenic and survival signals, as well as promoting epithelial–mesenchymal transition, invasion and tumour angiogenesis. Therapeutic strategies targeting FGFs and FGFRs in human cancer are therefore currently being explored. In the present review we will give an overview of FGF signalling, the main FGFR alterations found in human cancer to date, how they may contribute to specific cancer types and strategies for therapeutic intervention.
Cleavage of Notch1 by granzyme B disables its transcriptional activity
Authors: van Tetering Geert , Bovenschen Niels , Meeldijk Jan , van Diest Paul J. , Vooijs Marc
Published: June 2011

Granzyme-mediated cell death is the main pathway for cytotoxic lymphocytes to kill virus-infected and tumour cells. A major player in this process is GrB (granzyme B), which triggers apoptosis in both caspase-dependent and caspase-independent pathways. A caspase-independent substrate of GrB is the highly conserved transmembrane receptor Notch1. The GrB cleavage sites in Notch1 and functional consequences of Notch1 cleavage by GrB were unknown. In the present study, we confirmed that Notch1 is a direct and caspase-independent substrate of GrB. We demonstrate that GrB cleaved the intracellular Notch1 domain at least twice at two distinct aspartic acids, Asp1860 and Asp1961. GrB cleavage of Notch1 can occur in all subcellular compartments, during maturation of the receptor, at the membrane, and in the nucleus. GrB also displayed perforin-independent functions by cleaving the extracellular domain of Notch1. Overall, cleavage of Notch1 by GrB resulted in a loss of transcriptional activity, independent of Notch1 activation. We conclude that GrB disables Notch1 function, probably resulting in anti-cellular proliferation and cell death signals.
Effect of the top electrode materials on the resistive switching characteristics of TiO2 thin film
Authors: Oh Sang Chul , Jung Ho Yong , Lee Heon
Published: June 2011

Various metals, such as Pt, stainless steel (SUS), Al, Ni, and Ti, were used as a top electrode (TE) to evaluate the dependency of the resistive switching characteristics on the TE of the metal/TiO2/Pt structure. The variation of the chemical composition of TiO2 in the metal/TiO2/Pt structure before and after switching was examined to identify the factors affecting the resistive switching characteristics of the samples with various TE materials. In the case of TE/TiO2/Pt structures showing unstable resistive switching behavior, e.g., those with the Al, Ni, and Ti TEs, secondary ion mass spectrometry revealed an increase in the oxygen concentration at the interface area between the TE metal and TiO2. This suggests that the oxidation reaction at the interface between the TE metal and TiO2 might cause the TE/TiO2/Pt structure to exhibit unstable resistive switching characteristics. According to these results, the oxidation reaction at the interface between the metal TE and TiO2 thin film is a primary factor affecting the resistive switching characteristics of TiO2-based Resistive Random Access Memory devices.
Reconstructing phase dynamics of oscillator networks
Authors: Kralemann Björn , Pikovsky Arkady , Rosenblum Michael
Published: June 2011

We generalize our recent approach to the reconstruction of phase dynamics of coupled oscillators from data [B. Kralemann et al., Phys. Rev. E 77, 066205 (2008)] to cover the case of small networks of coupled periodic units. Starting from a multivariate time series, we first reconstruct genuine phases and then obtain the coupling functions in terms of these phases. Partial norms of these coupling functions quantify directed coupling between oscillators. We illustrate the method by different network motifs for three coupled oscillators and for random networks of five and nine units. We also discuss nonlinear effects in coupling.
Axis-switching in the vibrationless $\widetilde{A}\leftarrow \widetilde{X}$Ã←X̃ transition of the jet-cooled deuterated methyl peroxy radical CD3O2
Authors: Dupré Patrick
Published: June 2011

The jet-cooled high resolution spectrum of the vibrationless \documentclass[12pt]{minimal}\begin{document}$\widetilde{A}\leftarrow \widetilde{X}$\end{document}Ã←X̃ transition of the deuterated species of the methyl peroxy radical has been recently published in this journal (S. Wu, P. Dupré, P. Rupper, and T. A. Miller, J. Chem. Phys. 127, 224305 (2007))10.1063/1.2802202. The spectrum was analyzed using a rigid-rotor model with quadratic spin-rotation coupling. The analysis was based on the fit of ∼350 partially resolved line positions and was quite satisfactory. However, the full simulation of the spectral intensity clearly identifies a lack of ability to reproduce relatively small line clumps (“extra” lines) located between the two main central Q branches. This is indicating of an incomplete initial analysis. In the present paper we reanalyze this electronic transition by considering a reference-frame axis-switching resulting from the nuclear rearrangement associated to the electronic transition (spectra obtained at two different temperatures are considered). The potential energy hypersurfaces of the two electronic states are sufficiently dissimilar to induce changes in the molecule geometry, particularly, the angle \documentclass[12pt]{minimal}\begin{document}$\widehat{{\rm COO}},$\end{document} COO ̂, which induces a rotation (∼1.7°) of the principal axes of inertia located in the molecule symmetry plane. The present analysis is supported by a global fitting of the spectrum intensity and gives rise to a slightly different set of molecular constants. Attention is paid to the wavefunction symmetry assignment of a non-orthorhombic molecule. Couplings due to the torsion of the methyl group are discussed in the following paper (P. Dupre, J. Chem. Phys. 134, 244309 (2011))10.1063/1.3599954.
Topographic patterning by voltage-assisted tribocharging of a polymer
Authors: Kleiner A. , Marti O. , Dürig U. , Knoll A. , Gotsmann B.
Published: June 2011

A strong coupling between local charging and the specific volume of a polymer surface was exploited for topographic patterning. The charges were deposited locally using an atomic force microscope (AFM) tip sliding over the surface at moderate bias voltages of up to 5 V. The same tip was used to measure both topography (using the AFM imaging mode) and charge (using the Kelvin Probe Force Microscopy method). The height of the obtained structures can reach several nanometers. With an estimated depth of the charge of 1 to 10 nm, this corresponds to an increase of specific volume of 10 to 100%. It is shown that the structures and the charges can be erased independently from each other. The charging is discussed in the context of molecular rearrangements necessary to store charge.
Electrical spin accumulation with improved bias voltage dependence in a crystalline CoFe/MgO/Si system
Authors: Jeon Kun-Rok , Min Byoung-Chul , Shin Il-Jae , Park Chang-Yup , Lee Hun-Sung , Jo Young-Hun , Shin Sung-Chul
Published: June 2011

We report the electrical spin accumulation with enhanced bias voltage dependence in n-type Si, employing a crystalline CoFe/MgO tunnel contact. A sizable spin signal of ∼4.8 kΩμm2, a spin lifetime of ∼155 ps, and a spin diffusion length of ∼220 nm were obtained at 300 K. The spin signal and lifetime obtained in this system show consistent behavior with the temperature variation irrespective of the bias voltage. Notably, the spin signal exhibits nearly symmetric dependence with respect to the bias polarity, which is ascribed to the improved bias dependence of tunnel spin polarization.
Generation of alginate gel particles with AuNPs layers by polydimethylsiloxan template
Authors: Guo Zhi-Xiao , Zhang Meng , Zhao Li-Bo , Guo Shi-Shang , Zhao Xing-Zhong
Published: June 2011

The authors report a feasible and simple microfluidic approach for synthesizing anisotropic gel particles based on template method. By filling arrays of microwells with alginate hydrogel and synthesizing gold nanoparticles (AuNPs) on the gel surface, anisotropic alginate gel particles with single side gold nanoparticles layers were produced in microwells on the polydimethylsiloxan template. AuNPs and the anisotropic feature were characterized using scanning electron microscopy and x-ray photoelectron spectrum analyses. The anisotropic particles made of biocompatible gels could be released from the template and collected with uniform sizes, which might have a powerful potential in biological detection and sensing.
Low-temperature synthesis of graphene on nickel foil by microwave plasma chemical vapor deposition
Authors: Kim Y. , Song W. , Lee S. Y. , Jeon C. , Jung W. , Kim M. , Park C.-Y.
Published: June 2011

Microwave plasma chemical vapor deposition (MPCVD) was employed to synthesize high quality centimeter scale graphene film at low temperatures. Monolayer graphene was obtained by varying the gas mixing ratio of hydrogen and methane to 80:1. Using advantages of MPCVD, the synthesis temperature was decreased from 750 °C down to 450 °C. Optical microscopy and Raman mapping images exhibited that a large area monolayer graphene was synthesized regardless of the temperatures. Since the overall transparency of 89% and low sheet resistances ranging from 590 to 1855 Ω/sq of graphene films were achieved at considerably low synthesis temperatures, MPCVD can be adopted in manufacturing future large-area electronic devices based on graphene film.
Dephosphorylation of the nuclear factor of activated T cells (NFAT) transcription factor is regulated by an RNA-protein scaffold complex
Authors: Sharma Sonia , Findlay Gregory M. , Bandukwala Hozefa S. , Oberdoerffer Shalini , Baust Beate , Li Zhigang , Schmidt Valentina , Hogan Patrick G. , Sacks David B. , Rao Anjana
Published: June 2011

Nuclear factor of activated T cells (NFAT) proteins are Ca
2+
-regulated transcription factors that control gene expression in many cell types. NFAT proteins are heavily phosphorylated and reside in the cytoplasm of resting cells; when cells are stimulated by a rise in intracellular Ca
2+
, NFAT proteins are dephosphorylated by the Ca
2+
/
calmodulin
-dependent phosphatase calcineurin and translocate to the nucleus to activate target gene expression. Here we show that phosphorylated NFAT1 is present in a large cytoplasmic RNA-protein scaffold complex that contains a long intergenic noncoding RNA (lincRNA),
NRON
[noncoding (RNA) repressor of NFAT]; a scaffold protein, IQ motif containing GTPase activating protein (IQGAP); and three NFAT kinases, casein kinase 1, glycogen synthase kinase 3, and dual specificity tyrosine phosphorylation regulated kinase. Combined knockdown of
NRON
and IQGAP1 increased NFAT dephosphorylation and nuclear import exclusively after stimulation, without affecting the rate of NFAT rephosphorylation and nuclear export; and both
NRON
-depleted T cells and T cells from IQGAP1-deficient mice showed increased production of NFAT-dependent cytokines. Our results provide evidence that a complex of lincRNA and protein forms a scaffold for a latent transcription factor and its regulatory kinases, and support an emerging consensus that lincRNAs that bind transcriptional regulators have a similar scaffold function.
GABA exerts protective and regenerative effects on islet beta cells and reverses diabetes
Authors: Soltani Nepton , Qiu Hongmin , Aleksic Mila , Glinka Yelena , Zhao Fang , Liu Rui , Li Yiming , Zhang Nina , Chakrabarti Rabindranath , Ng Tiffany , Jin Tianru , Zhang Haibo , Lu Wei-Yang , Feng Zhong-Ping , Prud'homme Gerald J. , Wang Qinghua
Published: June 2011

Type 1 diabetes (T1D) is an autoimmune disease characterized by insulitis and islet β-cell loss. Thus, an effective therapy may require β-cell restoration and immune suppression. Currently, there is no treatment that can achieve both goals efficiently. We report here that GABA exerts antidiabetic effects by acting on both the islet β-cells and immune system. Unlike in adult brain or islet α-cells in which GABA exerts hyperpolarizing effects, in islet β-cells, GABA produces membrane depolarization and Ca2+influx, leading to the activation of PI3-K/Akt–dependent growth and survival pathways. This provides a potential mechanism underlying our in vivo findings that GABA therapy preserves β-cell mass and prevents the development of T1D. Remarkably, in severely diabetic mice, GABA restores β-cell mass and reverses the disease. Furthermore, GABA suppresses insulitis and systemic inflammatory cytokine production. The β-cell regenerative and immunoinhibitory effects of GABA provide insights into the role of GABA in regulating islet cell function and glucose homeostasis, which may find clinical application.
Micropatterned mammalian cells exhibit phenotype-specific left-right asymmetry
Authors: Wan Leo Q. , Ronaldson Kacey , Park Miri , Taylor Grace , Zhang Yue , Gimble Jeffrey M. , Vunjak-Novakovic Gordana
Published: June 2011

Left-right (LR) asymmetry (handedness, chirality) is a well-conserved biological property of critical importance to normal development. Changes in orientation of the LR axis due to genetic or environmental factors can lead to malformations and disease. While the LR asymmetry of organs and whole organisms has been extensively studied, little is known about the LR asymmetry at cellular and multicellular levels. Here we show that the cultivation of cell populations on micropatterns with defined boundaries reveals intrinsic cell chirality that can be readily determined by image analysis of cell alignment and directional motion. By patterning 11 different types of cells on ring-shaped micropatterns of various sizes, we found that each cell type exhibited definite LR asymmetry (
p
value down to 10
-185
) that was different between normal and cancer cells of the same type, and not dependent on surface chemistry, protein coating, or the orientation of the gravitational field. Interestingly, drugs interfering with actin but not microtubule function reversed the LR asymmetry in some cell types. Our results show that micropatterned cell populations exhibit phenotype-specific LR asymmetry that is dependent on the functionality of the actin cytoskeleton. We propose that micropatterning could potentially be used as an effective in vitro tool to study the initiation of LR asymmetry in cell populations, to diagnose disease, and to study factors involved with birth defects in laterality.
GIGANTEA directly activates
Flowering Locus T
in
Arabidopsis thaliana
Authors: Sawa Mariko , Kay Steve A.
Published: June 2011

Plants perceive environmental signals such as day length and temperature to determine optimal timing for the transition from vegetative to floral stages.
Arabidopsis
flowers under long-day conditions through the
CONSTANS
(
CO
)–
FLOWERING LOCUS T
(
FT
) regulatory module. It is thought that the environmental cues for photoperiodic control of flowering are initially perceived in the leaves. We have previously shown that GIGANTEA (GI) regulates the timing of
CO
expression, together with FLAVIN-BINDING, KELCH REPEAT, F BOX protein 1. Normally,
CO
and
FT
are expressed exclusively in vascular bundles, whereas GI is expressed in various tissues. To better elucidate the role of tissue-specific expression of GI in the flowering pathway, we established transgenic lines in which GI is expressed exclusively in mesophyll, vascular bundles, epidermis, shoot apical meristem, or root. We found that GI expressed in either mesophyll or vascular bundles rescues the late-flowering phenotype of the
gi-2
loss-of-function mutant under both short-day and long-day conditions. Interestingly, GI expressed in mesophyll or vascular tissues increases
FT
expression without up-regulating
CO
expression under short-day conditions. Furthermore, we examined the interaction between GI and
FT
repressors in mesophyll. We found that GI can bind to three
FT
repressors: SHORT VEGETATIVE PHASE (SVP), TEMPRANILLO (TEM)1, and TEM2. Finally, our chromatin immunoprecipitation experiments showed that GI binds to
FT
promoter regions that are near the SVP binding sites. Taken together, our data further elucidate the multiple roles of GI in the regulation of flowering time.
Magnetic field-induced reverse martensitic transformation in NiMnGaCu alloy
Authors: Li Panpan , Wang Jingmin , Jiang Chengbao , Xu Huibin
Published: June 2011

The reverse martensitic transformation was monitored by testing the x-ray diffraction patterns with increasing temperatures in an Ni46Mn33Ga17Cu4 alloy. A large magnetization change from a weak-magnetic martensite phase to a ferromagnetic austenite phase has been found on the M–T curves of heating cycle in this alloy. The reverse martensitic transformation temperatures have been lowered by 7 K under the magnetic field of 90 kOe. The magnetic field-induced reverse martensitic transformation has been confirmed at a fixed temperature in this alloy, demonstrating that another alloy performing the MFIRMT is discovered: NiMnGaCu alloy.
Growth of cubic InN on GaP(1 0 0) with GaN buffer by metalorganic chemical vapour deposition
Authors: Kwon S-Y , Sun Q , Kwak J , Seo H-C , Han J
Published: June 2011

Growth of cubic InN (c-InN) under N-rich condition was achieved by metalorganic chemical vapour deposition on GaP(1 0 0) substrates with a cubic GaN (c-GaN) buffer layer. Insertion of the c-GaN buffer layer suppressed In droplet formation in c-InN. X-ray diffraction and transmission electron microscopy investigations showed that the InN layers have zincblende structure with only a small fraction of oxide phase inclusions and no significant hexagonal InN is present. By systemically varying growth conditions, it was found that the c-InN growth is dominated mainly by In adatoms' surface diffusion and InN surface decomposition and three distinct regimes of c-InN growth are observed. The growth of c-InN on c-GaN/GaP(1 0 0) templates eventually followed a three-dimensional growth mode in the thermally activated growth regime and density and size distribution of c-InN dots significantly changed with substrate temperature and growth rate. These results provide a stronger understanding of the growth mechanism to design and engineer InN-based nanostructures with desired shapes for potential technological applications.
Presenting research findings
Authors: Peacock Janet L. , Peacock Philip J.
Published: June 2011

Communicating statistics 128

Producing journal articles 130

Research articles: abstracts 132

Research articles: introduction and methods sections 134

Research articles: results section 136

Research articles: discussion section 138

Presenting statistics: managing computer output 140

Presenting statistics: numerical results 142

Presenting statistics: P values and confidence intervals ...
Social learning spreads knowledge about dangerous humans among American crows
Authors: Cornell Heather N. , Marzluff John M. , Pecoraro Shannon
Published: June 2011

Individuals face evolutionary trade-offs between the acquisition of costly but accurate information gained firsthand and the use of inexpensive but possibly less reliable social information. American crows (
Corvus brachyrhynchos
) use both sources of information to learn the facial features of a dangerous person. We exposed wild crows to a novel ‘dangerous face’ by wearing a unique mask as we trapped, banded and released 7–15 birds at five study sites near Seattle, WA, USA. An immediate scolding response to the dangerous mask after trapping by previously captured crows demonstrates individual learning, while an immediate response by crows that were not captured probably represents conditioning to the trapping scene by the mob of birds that assembled during the capture. Later recognition of dangerous masks by lone crows that were never captured is consistent with horizontal social learning. Independent scolding by young crows, whose parents had conditioned them to scold the dangerous mask, demonstrates vertical social learning. Crows that directly experienced trapping later discriminated among dangerous and neutral masks more precisely than did crows that learned through social means. Learning enabled scolding to double in frequency and spread at least 1.2 km from the place of origin over a 5 year period at one site.
Experimental litter size reduction reveals costs of gestation and delayed effects on offspring in a viviparous lizard
Authors: Bleu Josefa , Massot Manuel , Haussy Claudy , Meylan Sandrine
Published: June 2011

Experimental studies have often been employed to study costs of reproduction, but rarely to study costs of gestation. Disentangling the relative importance of each stage of the reproductive cycle should help to assess the costs and benefits of different reproductive strategies. To that end, we experimentally reduced litter size during gestation in a viviparous lizard. We measured physiological and behavioural parameters during gestation and shortly after parturition, as well as survival and growth of females and their offspring. This study showed four major results. First, the experimental litter size reduction did not significantly affect the cellular immune response, the metabolism and the survival of adult females. Second, females with reduced litter size decreased their basking time. Third, these females also had an increased postpartum body condition. As postpartum body condition is positively related to future reproduction, this result indicates a gestation cost. Fourth, even though offspring from experimentally reduced litters had similar weight and size at birth as other offspring, their growth rate after birth was significantly increased. This shows the existence of a maternal effect during gestation with delayed consequences. This experimental study demonstrates that there are some costs to gestation, but it also suggests that some classical trade-offs associated with reproduction may not be explained by gestation costs.
Characterization of rutile passivation layers formed on Magnéli-phase titanium oxide inert anodes
Authors: Rowles Matthew Ryan , Scarlett Nicola V. Y. , Madsen Ian C. , McGregor Katherine
Published: June 2011

Anex situcharacterization study has been performed on rutile passivation layers on inert anodes used for molten salt electrochemical studies. Rutile layer thicknesses were estimated using a number ofex situmethods, including laboratory and synchrotron X-ray diffraction and optical microscopy. The only phases in the anode detected by diffraction were the Magnéli phases (TinO2n−1,n= 5–6) of the unreacted anode and rutile (TiO2), which forms on electrolysis. These measurements validate a previously developedin situenergy-dispersive X-ray diffraction analysis technique [Scarlett, Madsen, Evans, Coelho, McGregor, Rowles, Lanyon & Urban (2009).J. Appl. Cryst.42, 502–512].
Protocols for the Optimal Design of Multi‐Functional Cellular Structures: From Hypersonics to Micro‐Architected Materials
Authors: Valdevit Lorenzo , Jacobsen Alan J. , Greer Julia R. , Carter William B.
Published: June 2011

Cellular materials with periodic architectures have been extensively investigated over the past decade for their potential to provide multifunctional solutions for a variety of applications, including lightweight thermo‐structural panels, blast resistant structures, and high‐authority morphing components. Stiffer and stronger than stochastic foams, periodic cellular materials lend themselves well to geometry optimization, enabling a high degree of tailorability and superior performance benefits. This article reviews a commonly established optimal design protocol, extensively adopted at the macro‐scale for both single and multifunctional structures. Two prototypical examples are discussed: the design of strong and lightweight sandwich beams subject to mechanical loads and the combined material/geometry optimization of actively cooled combustors for hypersonic vehicles. With this body of literature in mind, we present a motivation for the development of micro‐architected materials, namely periodic multiscale cellular materials with overall macroscopic dimensions yet with features (such as the unit cell or subunit cell constituents) at the micro‐ or nano‐scale. We review a suite of viable manufacturing approaches and discuss the need for advanced experimental tools, numerical models, and optimization strategies. In analyzing challenges and opportunities, we conclude that the technology is approaching maturity for the development of micro‐architected materials with unprecedented combinations of properties (e.g., specific stiffness and strength), with tremendous potential impact on a number of fields.
The first five days: field and laboratory investigations during the early stages of the equine influenza outbreak in Australia, 2007
Authors: Kirkland PD , Davis RJ , Wong D , Ryan D , Hart K , Corney B , Hewitson G , Cooper K , Biddle A , Eastwood S , Slattery S , Rayward D , Evers M , Wright T , Halpin K , Selleck P , Watson J
Published: June 2011

Until August 2007, Australia was one of only three countries internationally recognised to be free of equine influenza (EI). This report documents the diagnosis of the first cases of EI in Australian horses and summarises the investigations that took place over the next 5 days. During that time, a multifocal outbreak was identified across eastern New South Wales and south‐eastern Queensland. The use of an influenza type A pan‐reactive real‐time reverse transcription polymerase chain reaction allowed rapid confirmation of suspect cases of EI.
Longitudinal study describing the clinical signs observed in horses naturally infected with equine influenza
Authors: Faehrmann P , Riddell K , Read AJ
Published: June 2011

We describe the clinical signs and disease course during an outbreak of equine influenza (EI) in naïve horses in a police stables in Sydney, New South Wales, Australia.
Vaccination program in the response to the 2007 equine influenza outbreak in Australia
Authors: Perkins NR , Webster WR , Wright T , Denney I , Links I
Published: June 2011

At the time of the initial notification of the occurrence of equine influenza (EI) in Australia in August 2007, vaccination was restricted to horses for which it was an import requirement and only with the approval of the state or territory Chief Veterinary Officer. This paper describes the complexities involved in the selection of a vaccine and its distribution. A combination of ring, predictive and blanket vaccination was implemented during the response. The specific vaccination programs, including its use in buffer zones and for movement of horses, the performance of the vaccine, any adverse reactions and the effect on exposure of vaccinated horses to circulating virus, are also described. Vaccination is considered to have made a valuable contribution to the containment and subsequent eradication of EI from Australia and to risk management in the resumption of horse activities in affected areas from December 2007. Movement restrictions and other biosecurity measures were critically important in controlling the spread of EI and contributing to its eventual eradication, and vaccination was an aid to these measures.
Clinical outcomes and virology of equine influenza in a naïve population and in horses infected soon after receiving one dose of vaccine
Authors: Kannegieter NJ , Frogley A , Crispe E , Kirkland PD
Published: June 2011

As part of the control measures of the equine influenza (EI) outbreak, in addition to the strategic use of vaccination to provide buffer zones around infected populations, approval was obtained to vaccinate Thoroughbred racing horses. We review the clinical expression of the disease and virus excretion in a population of racehorses that were exposed to EI approximately 7 days after administration of a single dose of the canarypox‐vectored recombinant compared with a similar unvaccinated population of horses at a nearby racetrack. Although this study was undertaken opportunistically and under the difficult field conditions that prevailed during the outbreak, our observations demonstrate that an appropriate vaccine can be effectively used as a disease control measure, even in the face of an outbreak, and therefore should be rapidly implemented as soon as there is evidence of infection in a naïve population.
Pharmacotherapy and Pregnancy: Highlights from the Third International Conference for Individualized Pharmacotherapy in Pregnancy
Authors: Haas David M. , Gallauresi Beverly , Shields Kristine , Zeitlin Deborah , Clark Shannon M. , Hebert Mary F. , Ren Zhaoxia , Nallani Srikanth C. , Meslin Eric M. , Feibus Karen B. , Koren Gideon , Goebel W. Scott , Easterling Thomas , Denne Scott C. , Flockhart David A. , Renbarger Jamie L.
Published: June 2011

To address provider struggles to provide evidence‐based, rational drug therapy to pregnant women, this third Conference was convened to highlight the current progress and research in the field. Speakers from academic centers, industry, and governmental institutions spoke about: the Food and Drug Administration’s role in pregnancy pharmacology and the new labeling initiative; drug registries in pregnancy; the pharmacist’s role in medication use in pregnancy; therapeutic areas such as preterm labor, gestational diabetes, nausea and vomiting in pregnancy, and hypertension; breast‐feeding and medications; ethical challenges for consent in pregnancy drug studies; the potential for cord blood banks; and concerns about the fetus when studying drugs in pregnancy. The Conference highlighted several areas of collaboration within the current Obstetrics Pharmacology Research Units Network and hoped to educate providers, researchers, and agencies with the common goal to improve the ability to safely and effectively use individualized pharmacotherapy in pregnancy. Clin Trans Sci 2011; Volume 4: 204–209
NASH: A global health problem
Authors: Sanyal Arun J.
Published: June 2011

Non‐alcoholic fatty liver disease (NAFLD) is a major public health problem both in the Western world and in the East. This is mainly due to the high prevalence of the disease and its effects on the individual with NAFLD. In the USA, it is estimated that approximately a third of the general population has NAFLD. Increasing age, obesity and the presence of multiple features of metabolic syndrome, especially diabetes, are associated with a higher probability of having non‐alcoholic steatohepatitis (NASH). In the individual with NAFLD, excess hepatic fat is associated with an increased risk of developing diabetes, hypertension, cardiovascular events, abnormal resting electrocardiography and endothelial dysfunction. These findings have been corroborated in studies in teenagers as well as adults. There is also an increase in cardiovascular mortality, especially in those with NASH. In addition, there is an increased risk of death from a variety of non‐hepatocellular cancers. From a liver perspective, NAFLD is associated with a 15–20% risk of progression to cirrhosis. The disease progresses more rapidly in those with diabetes, increasing age and obesity. The PNPLA3 gene mutation at position 148 is associated with not only steatosis, but with the likelihood of having steatohepatitis and increased inflammation and fibrosis. Once cirrhosis develops, the liver disease decompensates at the rate of 3–4% per year. NASH‐related cirrhosis is a risk factor for hepatocellular cancer. All of these factors indicate that NAFLD is a common condition that has significant adverse health consequences for those who are afflicted. It is therefore a major public health hazard throughout the world
Pharmacological therapy for non‐alcoholic steatohepatitis: How efficient are thiazolidinediones?
Authors: Ratziu Vlad , Pienar Loredana
Published: June 2011

Although diet and lifestyle changes are the first‐line therapy in patients with non‐alcoholic steatohepatitis (NASH), few patients are able to successfully implement these measures over the long run while others have an advanced disease requiring specific pharmacological therapy. Because insulin resistance is the underlying condition favoring the occurrence of NASH, insulin sensitizers have been tested in this condition although available trials are heterogenous in terms of choice of the drug, dosage, length of therapy and patient profile. Overall, thiazolidinediones reduce aminotransferase levels and induce a strong anti‐steatogenic response. Most studies have shown an improvement in inflammation and liver cell injury while none have convincingly demonstrated an effect on fibrosis regression. The optimal duration of therapy is unknown as prolonged therapy does not seem to induce additional histological benefit. Although some tolerance issues and safety concerns, in particular cardiovascular, have been raised, thiazolidinediones are the class of drugs with the largest body of evidence in the treatment of NASH so far and can be successfully used in some patients with this disease.
Assessment of scatter for the micro‐CT subsystem of the trimodality FLEX Triumph™ preclinical scanner
Authors: Gutierrez Daniel , Zaidi Habib
Published: June 2011

Purpose:

This work aims at assessing, through experimental measurements and Monte Carlo calculations, the scatter to primary ratio (SPR) for the micro‐CT subsystem of the FLEX Triumph™ preclinical PET‐CT scanner to improve its quantitative capabilities.

Methods:

Experimental measurements were carried out using the single blocker method, where five cylindrical blockers with diameters ranging between 3 and 11.65 mm were used to assess the SPR without the blocker through interpolation. Because of the vertical layout of the imaging device, the blocker was placed over rat‐sized and mouse‐sized phantoms and central and peripheral SPR values were obtained by rotating the source and detector. The influence of beam energy (30, 50, and 80 kVp), geometrical magnification (1.3 and 2.0) and phantom diameter (25 and 50 mm) and density (polyethylene and water) were investigated. Monte Carlo (MC) simulations using the MCNP4C code were also performed and compared to experimental results to validate their accuracy.

Results:

The highest difference was found in the extreme peripheral region of the small phantom, while the maximum difference at the center of the phantom is about 6%, indicating that MC simulations can reproduce well the experimental results, at least in the region inside the phantom. The maximal SPR (0.562) was obtained for the large phantom at 30 kVp and a magnification of 1.3. The full SPR profile was calculated using MC simulations and used to express its dependency on beam energy (quadratic), air gap (asymptotic), and phantom diameter (quadratic).

Conclusions:

The obtained results are in good agreement with theoretical predictions. MC simulations were valuable for the evaluation of the influence of various acquisition parameters on the SPR estimates.
Combinations of Macrolide Resistance Determinants in Field Isolates of Mannheimia haemolytica and Pasteurella multocida
Authors: Desmolaize Benoit , Rose Simon , Wilhelm Cornelia , Warrass Ralf , Douthwaite Stephen
Published: June 2011

Respiratory tract infections in cattle are commonly associated with the bacterial pathogens
Mannheimia haemolytica
and
Pasteurella multocida
. These infections can generally be successfully treated in the field with one of several groups of antibiotics, including macrolides. A few recent isolates of these species exhibit resistance to veterinary macrolides with phenotypes that fall into three distinct classes. The first class has type I macrolide, lincosamide, and streptogramin B antibiotic resistance and, consistent with this, the 23S rRNA nucleotide A2058 is monomethylated by the enzyme product of the
erm
(42) gene. The second class shows no lincosamide resistance and lacks
erm
(42) and concomitant 23S rRNA methylation. Sequencing of the genome of a representative strain from this class,
P. multocida
3361, revealed macrolide efflux and phosphotransferase genes [respectively termed
msr
(E) and
mph
(E)] that are arranged in tandem and presumably expressed from the same promoter. The third class exhibits the most marked drug phenotype, with high resistance to all of the macrolides tested, and possesses all three resistance determinants. The combinations of
erm
(42),
msr
(E), and
mph
(E) are chromosomally encoded and intermingled with other exogenous genes, many of which appear to have been transferred from other members of the
Pasteurellaceae
. The presence of some of the exogenous genes explains recent reports of resistance to additional drug classes. We have expressed recombinant versions of the
erm
(42),
msr
(
E
), and
mph
(
E
) genes within an isogenic
Escherichia coli
background to assess their individually contributions to resistance. Our findings indicate what types of compounds might have driven the selection for these resistance determinants.
Reduction in Membrane Phosphatidylglycerol Content Leads to Daptomycin Resistance in Bacillus subtilis
Authors: Hachmann Anna-Barbara , Sevim Elif , Gaballa Ahmed , Popham David L. , Antelmann Haike , Helmann John D.
Published: June 2011

Daptomycin (DAP) is a cyclic lipopeptide that disrupts the functional integrity of the cell membranes of Gram-positive bacteria in a Ca
2+
-dependent manner. Here we present genetic, genomic, and phenotypic analyses of an evolved DAP-resistant isolate, Dap
R
1, from the model bacterium
Bacillus subtilis
168. Dap
R
1 was obtained by serial passages with increasing DAP concentrations, is 30-fold more resistant than the parent strain, and displays cross-resistance to vancomycin, moenomycin, and bacitracin. Dap
R
1 is characterized by aberrant septum placement, notably thickened peptidoglycan at the cell poles, and pleiotropic alterations at both the transcriptome and proteome levels. Genome sequencing of Dap
R
1 revealed 44 point mutations, 31 of which change protein sequences. An intermediate isolate that was 20-fold more resistant to DAP than the wild type had only three of these point mutations: mutations affecting the cell shape modulator gene
mreB
, the stringent response gene
relA
, and the phosphatidylglycerol synthase gene
pgsA
. Genetic reconstruction studies indicated that the
pgsA
(
A64V
) allele is primarily responsible for DAP resistance. Allelic replacement with wild-type
pgsA
restored DAP sensitivity to wild-type levels. The additional point mutations in the evolved strain may contribute further to DAP resistance, serve to compensate for the deleterious effects of altered membrane composition, or represent neutral changes. These results suggest a resistance mechanism by which reduced levels of phosphatidylglycerol decrease the net negative charge of the membrane, thereby weakening interaction with the positively charged Ca
2+
-DAP complex.
ELECTRICAL CHARACTERIZATION OF VAPOR-DEPOSITED SINGLE CdS NANOWIRE
Authors: FU X. L. , TANG W. H. , LI L. H.
Published: June 2011

In this work, we synthesized chromium-doped CdS nanowires by simple vapor deposition. And the current–voltage characteristics of single CdS nanowire have been studied. The results from electrical transport measurements on the field-effect transistors showed that the nanowire was an n-type semiconductor. In addition, the Au / CdS nanowire device exhibited clear diode-like behavior, and a thermally-assisted tunneling mechanism, which dominates the transport of carriers above the metal–semiconductor contact in the diode, was discussed in detail.
TRANSITION TO CHAOS IN A SHELL MODEL OF TURBULENCE WITH THE CHANGE OF THE VISCOSITY
Authors: YUAN GUO-YONG , XU LIN , LIU YA-PING , HE XIAO-YAN , YANG SHI-PING
Published: June 2011

In this paper, a shell model for the energy cascade in three-dimensional turbulence at varying the viscosity is studied. When the viscosity parameter ν is large enough, the phase orbit of each shell in the system is a stable fixed point. As ν diminishes down to a critical value, the point becomes unstable and a stable periodic orbit appears via a supercritical Hopf bifurcation. For the quasiperiodic solution of the system, each shell has a own dynamic behavior. At ν = 6.88×10-5, the system initiates a complex scenario of bifurcations, where the phase orbits of un and un+3 begin to form a intersected section. Farther decreasing ν, we observe a transition from quasiperiodic solution to chaos through a sequence of Neimark–Sacker bifurcations. The behaviors can be vividly shown in the change of the average energy function E with ν. At last, the transition to chaos in the ν–δ parameter space is also obtained.
EFFECT OF THE ROTATION ON WAVE MOTION THROUGH CYLINDRICAL BORE IN A MICROPOLAR POROUS MEDIUM
Authors: MAHMOUD S. R. , ABD-ALLA A. M. , EL-SHEIKH M. A.
Published: June 2011

In the present paper, we have studied the propagation of axial symmetric cylindrical surface waves through rotating cylindrical bore in a micropolar porous medium of infinite extent possessing cubic symmetry. The frequency equation for surface wave propagation in the micropolar porous medium has been derived and liquid filled bore are derived. The effect of the rotation on phase velocity of surface wave has been studied in detail. Radius of bore and other material parameters for empty and liquid filled bore are derived. A particular case of interest has been deduced. Numerical results have been obtained and illustrated graphically to understand the behavior of phase velocity versus wave number of a wave. The results have indicated that the effect of rotation on phase velocity is highly pronounced. Comparisons are made in the absence of rotation.
MINKOWSKI SUM SELECTION AND FINDING
Authors: LUO CHENG-WEI , LIU HSIAO-FEI , CHEN PENG-AN , CHAO KUN-MAO
Published: June 2011

Let P,Q ⊆ ℝ2 be two n-point multisets and Ar ≥ b be a set of λ inequalities on x and y, where A ∈ ℝλ×2, [Formula: see text], and b ∈ ℝλ. Define the constrained Minkowski sum(P ⊕ Q)Ar≥ b as the multiset {(p + q)|p ∈ P, q ∈ Q,A(p + q) ≥ b }. Given P, Q, Ar ≥ b , an objective function f : ℝ2 → ℝ, and a positive integer k, the MINKOWSKI SUM SELECTION problem is to find the kth largest objective value among all objective values of points in (P ⊕ Q)Ar≥ b . Given P, Q, Ar ≥ b , an objective function f : ℝ2 → ℝ, and a real number δ, the MINKOWSKI SUM FINDING problem is to find a point (x*, y*) in (P ⊕ Q)Ar≥ b such that |f(x*,y*) - δ| is minimized. For the MINKOWSKI SUM SELECTION problem with linear objective functions, we obtain the following results: (1) optimal O(n log n)-time algorithms for λ = 1; (2) O(n log 2 n)-time deterministic algorithms and expected O(n log n)-time randomized algorithms for any fixed λ > 1. For the MINKOWSKI SUM FINDING problem with linear objective functions or objective functions of the form [Formula: see text], we construct optimal O(n log n)-time algorithms for any fixed λ ≥ 1. As a byproduct, we obtain improved algorithms for the LENGTH-CONSTRAINED SUM SELECTION problem and the DENSITY FINDING problem.