bluuebunny/crossref_metadata_2025 huggingface dataset:
Quasiparticle relaxation across the multiple superconducting gaps in the electron-doped BaFe1.85Co0.15As2
Authors: Ren Y. H. , Gong Y. , Nosach T. , Li J. , Tu J. J. , Li L. J. , Cao G. H. , Xu Z. A.
Published: March 2012

We study the quasiparticle relaxation dynamics in the electron-doped superconductor, BaFe1.85Co0.15As2 (BFCA) by using optical spectroscopy in both time and frequency domains. The estimate of the electron−phonon (el–ph) coupling constant from quasiparticle relaxation rate in time domain gives a value of ∼0.16 that is much too small to give a TC of 25 K. We obtain a negative value of the Coulomb pseudopotential that implies that the el−ph interaction alone is not strong enough to induce a superconducting transition in BFCA. More importantly, the electron-boson spectral function determined from optical scattering rate in frequency domain does not resemble the measured phonon density of states and has a dominant peak (at 53 meV) beyond the phonon frequencies. Our results support that the BFCA is a multi-gap s-wave superconductor and that its electron pairing is based on a spin-mediated pairing mechanism.
Magnetism of directly ordered Sm-Co clusters
Authors: Balamurugan B. , Skomski R. , Li X. Z. , Hadjipanayis G. C. , Sellmyer D. J.
Published: March 2012

Sm-Co bulk alloys have shown superior permanent-magnet properties, but research on Sm-Co nanoparticles is challenging because of the need to control particle size, size-distribution, crystalline ordering, and phase purity. In the present study, a cluster-deposition method was used to produce Sm-Co nanoparticles having desired crystal structures without the requirement of subsequent high-temperature thermal annealing. Poorly crystallized SmCo5 nanoparticles exhibit a low room-temperature coercivity of only 100 Oe, whereas crystalline SmCo5 and Sm2Co17 nanoparticles show room-temperature coercivities of 2000 and 750 Oe, respectively. The direct synthesis of Sm-Co nanoparticles having sizes of less than 10 nm and a high degree of atomic ordering is an important step toward creating nanoparticle building blocks for permanent-magnets and other significant applications.
Magnetocaloric effect in epitaxial La0.56Sr0.44MnO3 alloy and digital heterostructures
Authors: Belyea Dustin D. , Santos Tiffany S. , Miller Casey W.
Published: March 2012

This work investigates the magnetocaloric effect of two epitaxial manganite heterostructures, one being a single layer La0.56Sr0.44MnO3 alloy with randomly distributed La and Sr cations, the other a digitally synthesized superlattice of LaMnO3 and SrMnO3 fabricated to be compositionally identical to the alloy. The magnetic entropy change and relative cooling power were larger for the alloy than the superlattice, though both are suppressed relative to bulk materials. These results indicate that disorder of the A-site cation species in the perovskite structure may play a crucial role in defining the magnetocaloric effect in complex oxide materials.
Enhancement of interfacial specific resistance by the insertion of Fe(001) layers between alternate monatomic [Fe/Co]n superlattices and Ag spacer
Authors: Jung J. W , Shiokawa Y. , Jin Z. , Doi M. , Sahashi M.
Published: March 2012

The bulk and interface spin scattering asymmetric coefficients, βF and γF/N, respectively, as well as the interfacial specific resistance, AR*F/N, contribute to the total resistance change-area product, ΔRA, in current-perpendicular-to-plane (CPP) geometry. In this paper, we report the effect of the insertion of a 1 nm Fe layer into ferromagnetic (F)/non-ferromagnetic (N) interfaces on the spin dependent transport properties. Using the Valet-Fert theory based on the two-current model in which ΔRA is obtained as a function of thicknesses of the ferromagnetic layer (3, 4, and 5 nm), we experimentally deduced the values of βF, γF/N, and AR*F/N of exchange-biased spin valves (EBSVs) for an artificially ordered B2 state Fe50Co50 alloy as a magnetic layer and an Ag spacer layer.
The effect of field-quenching fabrication on the magnetoimpedance response in Co66Fe4Ni1Si15B14 amorphous ribbons
Authors: Sánchez T. , Bonastre J. , Santos J. D. , Sánchez M. L. , Chizhik A. , González J. , Suñol J. J. , Hernando B.
Published: March 2012

The magnetoimpedance response of the soft amorphous magnetic CoFeNiSiB alloy can be improved by the application of a small magnetic field during the fabrication process. Calorimetric and magnetic (hysteresis loop) behavior as well as magnetoimpedance response of melt-spun ribbons obtained by two different ways of production processes are analyzed in this work. The crystallization dynamics also show small differences. High sensitivities to the applied magnetic field up to 320%/Oe are observed when a small transverse anisotropy is induced in the ribbon sample during the fabrication process under the action of a magnetic field.
Multi-frequency magnonic logic circuits for parallel data processing
Authors: Khitun Alexander
Published: March 2012

We describe and analyze magnonic logic circuits enabling parallel data processing on multiple frequencies. The circuits combine bi-stable (digital) input/output elements and an analog core. The data transmission and processing within the analog part is accomplished by the spin waves, where logic 0 and 1 are encoded into the phase of the propagating wave. The latter makes it possible to utilize a number of bit carrying waves on different frequencies for parallel data processing. The operation of the magnonic logic circuits is illustrated by numerical modeling. We also present the estimates on the potential functional throughput enhancement and compare it with scaled CMOS. The described multi-frequency approach offers a fundamental advantage over the transistor-based circuitry and may provide an extra dimension for the functional throughput enhancement. The shortcoming and potentials issues are also discussed.
Counting cells with a low-cost integrated microfluidics-waveguide sensor
Authors: Garcia Daniel , Ghansah Isaac , LeBlanc John , Butte Manish J.
Published: March 2012

The capability to count cells from biofluids at low cost has important diagnostic implications in resource-poor settings. Many approaches have been developed to address this important need, and while most envision a low per-test cost, the detector instrument can be quite expensive. In this report, we present a novel device that enables low-cost and rapid counting of cells from a drop of blood. We demonstrate a shallow, buried, planar waveguide fabricated by ion exchange in glass that underlies a microfluidic structure for capturing cells. Laser light transmitted through the waveguide was attenuated by the number of metal nanoparticles tagged to the cells because of the interaction of the metal particles with the evanescent field of the waveguide. Calibration of the sensor using bead-tagged lymphocytes captured from human blood showed that the sensor could semi-quantitatively count as few as 100 cells/µL of blood. This technology enables the enumeration of specifically captured cells, allowing for a point-of-care, hand-held device for fast and affordable cell counting in screening, remote, or resource-poor settings.
Oxygen cluster anions revisited: Solvent-mediated dissociation of the core O4− anion
Authors: Khuseynov Dmitry , Goebbert Daniel J. , Sanov Andrei
Published: March 2012

The electronic structure and photochemistry of the O2n−(H2O)m, n = 1–6, m = 0–1 cluster anions is investigated at 532 nm using photoelectron imaging and photofragment mass-spectroscopy. The results indicate that both pure oxygen clusters and their hydrated counterparts with n ≥ 2 form an O4− core. Fragmentation of these clusters yields predominantly O2− and O2−·H2O anionic products, with the addition of O4− fragments for larger parent clusters. The fragment autodetachment patterns observed for O6− and larger O2n− species, as well as some of their hydrated counterparts, indicate that the corresponding O2− fragments are formed in excited vibrational states (v ≥ 4). Yet, surprisingly, the unsolvated O4− anion itself does not show fragment autodetachment at 532 nm. It is hypothesized that the vibrationally excited O2− is formed in the intra-cluster photodissociation of the O4− core anion via a charge-hopping electronic relaxation mechanism mediated by asymmetric solvation of the nascent photofragments: O4− → O2−(X2Πg) + O2(a1Δg) → O2(X3Σg−) + O2−(X2Πg). This process depends on the presence of solvent molecules and leads to vibrationally excited O2−(X2Πg) products.
Thermal effects in 2.x μm vertical-external-cavity-surface-emitting lasers
Authors: Pierściński K. , Pierścińska D. , Bugajski M. , Manz C. , Rattunde M.
Published: March 2012

The thermal behavior of vertical-external-cavity-surface-emitting lasers (VECSELs) is investigated. The temperature distribution in operating VECSELs has been experimentally determined for various operating conditions and different cooling schemes. The implementation of the thermoreflectance technique for the thermal analysis of VECSELs is demonstrated. This technique allows for high resolution mapping of a temperature increase resulting from the optical pumping of the VECSEL. The influence of a heatspreader on the VECSEL temperature is investigated. It is demonstrated that the use of an intracavity heatspreader bonded to the VECSEL chip causes a pronounced decrease of the temperature of the device. From the heat balance in the device, the lowering of the temperature of the VECSEL during operation is predicted. This is experimentally confirmed.
Deformation, breakup and motion of a perfect dielectric drop in a quadrupole electric field
Authors: Deshmukh Shivraj. D. , Thaokar Rochish. M.
Published: March 2012

A detailed nonlinear analysis of the deformation and breakup of a perfect dielectric (PD) drop, suspended in another perfect dielectric fluid, in the presence of a quadrupole electric field is presented using analytical (asymptotic) and numerical (boundary integral) methods. The quadrupole field is the simplest kind of an axisymmetric non-uniform electric field. A drop, when placed at the center of such a field, does not translate, thus allowing systematic investigation of the effect of non-uniformity of the electric field. The deformation of a drop under a quadrupole field for PD-PD systems exhibits several novel features as compared to that of a drop under a uniform electric field. The first order analysis predicts oblate deformation for a PD-PD system when the dielectric constant of the suspending medium is larger than that of the drop (Q = εi/εe < 1). This is in sharp contrast to uniform electric fields where oblate shapes are observed only in leaky dielectric systems. Prolate shapes are observed for Q > 1, and the deformation is larger than that for uniform fields for similar electric capillary numbers. The steady state shapes are defined by higher harmonics as compared to the uniform field. At large capillary numbers, prolate deformations (Q > 1) show breakup whereas oblate deformations (Q < 1) do not. Positive and negative dielectrophoresis is observed when the drop is placed off center, and its translation and simultaneous deformation under quadrupole fields is also investigated. The electro-hydrostatics is unaffected by the viscosity ratio. However, the breakup of the drop and the dielectrophoretic motion and deformation strongly depend upon the viscosity ratio.
Temperature dependence of coercive field of ZnFe2O4 nanoparticles
Authors: Mendonça E. C. , Jesus C. B. R. , Folly W. S. D. , Meneses C. T. , Duque J. G. S. , Coelho A. A.
Published: March 2012

Structural and magnetic measurements on ZnFe2O4 nanoparticles obtained through co-precipitation chemical method are reported. The Rietveld analysis of X-ray patterns reveal that (i) our samples are single phase, and (ii) the average particle size increases with synthesis temperature. The zero-field-cooled (ZFC) and field-cooled (FC) magnetization measurements show that the average blocking temperature increases for increasing mean particle size. Besides, one can observe via magnetization measurements that our particle size distribution also increases as a function of synthesis temperature. Finally, we have observed that the coercive field does not decay with the square root of temperature following the Néel relaxation and the Bean-Livingston approaches. In order to fit our experimental data, we have used a generalized model that proposes a temperature dependence of blocking temperature due to the coexistence of blocked and unblocked particles. This proposed generalized model shows good agreement with our experimental results.
Effect of intramolecular charge transfer on the two-photon absorption behavior of multibranched triphenylamine derivations
Authors: He Xing , Xu Bin , Liu Yuqiang , Yang Yanqiang , Tian Wenjing
Published: March 2012

Solvent polarity effect on the absorption spectra and fluorescence spectra of a series of multibranched structure triphenylamine derivations (Ph-G0, Ph-G1, and Ph-G2) were analyzed to reveal the factors that determine the two-photon absorption (TPA) ability in these molecules. It was found that the dominate factor is the extent of intramolecular charge transfer upon photoexcitation, rather than coherent coupling between branches. This result suggests that it is more effective to change the electron withdrawing ability or electron giving ability of branches and core than simply increase the number of branches for enhancing the TPA ability in multibranched structure molecules.
The electronic states of 1,2,4-triazoles: A study of 1H- and 1-methyl-1,2,4-triazole by vacuum ultraviolet photoabsorption and ultraviolet photoelectron spectroscopy and a comparison with ab initio configuration interaction computations
Authors: Palmer Michael H. , Camp Philip J. , Hoffmann Søren Vrønning , Jones Nykola C. , Head Ashley R. , Lichtenberger Dennis L.
Published: March 2012

The first vacuum ultraviolet absorption spectrum of a 1,2,4-triazole has been obtained and analyzed in detail, with assistance from both an enhanced UV photoelectron spectroscopic study and ab initio multi-reference multi-root configuration interaction procedures. For both 1H- and 1-methyl-1,2,4-triazoles, the first ionization energy bands show complex vibrational structure on the low-energy edges of otherwise unstructured bands. Detailed analysis of these bands confirms the presence of three ionized states. The 6–7 eV VUV spectral region shows an unusual absorption plateau, which is interpreted in terms of the near degeneracy of the first two ionization energies, leading to a pseudo Jahn-Teller effect. The “fingerprint” of the ionization spectrum yields band origins for several Rydberg states. The configuration interaction study shows that although the equilibrium structure for the first cation is effectively planar, the second cation shows significant twisting of the ring system. Some calculated singlet electronic states also show skeletal twisting in which the ring C–H is substantially out of plane.
Accelerating relativistic reference frames in Minkowski space-time
Authors: Turyshev Slava G. , Minazzoli Olivier L. , Toth Viktor T.
Published: March 2012

We study accelerating relativistic reference frames in Minkowski space-time under the harmonic gauge. It is well-known that the harmonic gauge imposes constraints on the components of the metric tensor and also on the functional form of admissible coordinate transformations. These two sets of constraints are equivalent and represent the dual nature of the harmonic gauge. We explore this duality and show that the harmonic gauge allows presenting an accelerated metric in an elegant form that depends only on two harmonic potentials. It also allows reconstruction of the spatial structure of the post-Galilean coordinate transformation functions relating inertial and accelerating frames. The remaining temporal dependence of these functions together with corresponding equations of motion are determined from dynamical conditions, obtained by constructing the relativistic proper reference frame of an accelerated test particle. In this frame, the effect of external forces acting on the observer is balanced by the fictitious frame-reaction force that is needed to keep the test particle at rest with respect to the frame, conserving its relativistic linear momentum. We find that this approach is sufficient to determine all the terms of the coordinate transformation. The same method is then used to develop the inverse transformations. The resulting post-Galilean coordinate transformations extend the Poincaré group on the case of accelerating observers. We present and discuss the resulting coordinate transformations, relativistic equations of motion, and the structure of the metric tensors corresponding to the relativistic reference frames involved.
Suppressing nano-scale stick-slip motion by feedback
Authors: Zhang Jing , Wu Re-Bing , Miao Lei , Xi Ning , Li Chun-Wen , Wang Yue-Chao , Tarn Tzyh-Jong
Published: March 2012

When a micro cantilever with a nano-scale tip is manipulated on a substrate with atomic-scale roughness, the periodic lateral frictional force and stochastic fluctuations may induce stick-slip motion of the cantilever tip, which greatly decreases the precision of the nano manipulation. This unwanted motion cannot be reduced by open-loop control especially when there exist parameter uncertainties in the system model, and thus needs to introduce feedback control. However, real-time feedback cannot be realized by the existing virtual reality virtual feedback techniques based on the position sensing capacity of the atomic force microscopy (AFM). To solve this problem, we propose a new method to design real-time feedback control based on the force sensing approach to compensate for the disturbances and thus reduce the stick-slip motion of the cantilever tip. Theoretical analysis and numerical simulations show that the controlled motion of the cantilever tip tracks the desired trajectory with much higher precision. Further investigation shows that our proposal is robust under various parameter uncertainties. Our study opens up new perspectives of real-time nano manipulation.
The plastic and liquid phases of CCl3Br studied by molecular dynamics simulations
Authors: Caballero Nirvana B. , Zuriaga Mariano , Carignano Marcelo , Serra Pablo
Published: March 2012

We present a molecular dynamics study of the liquid and plastic crystalline phases of CCl3Br. We investigated the short-range orientational order using a recently developed classification method and we found that both phases behave in a very similar way. The only differences occur at very short molecular separations, which are shown to be very rare. The rotational dynamics was explored using time correlation functions of the molecular bonds. We found that the relaxation dynamics corresponds to an isotropic diffusive mode for the liquid phase but departs from this behavior as the temperature is decreased and the system transitions into the plastic phase.
Investigation of vertical cavity surface emitting laser dynamics for neuromorphic photonic systems
Authors: Hurtado A. , Schires K. , Henning I. D. , Adams M. J.
Published: March 2012

We report an approach based upon vertical cavity surface emitting lasers (VCSELs) to reproduce optically different behaviors exhibited by biological neurons but on a much faster timescale. The technique proposed is based on the polarization switching and nonlinear dynamics induced in a single VCSEL under polarized optical injection. The particular attributes of VCSELs and the simple experimental configuration used in this work offer prospects of fast, reconfigurable processing elements with excellent fan-out and scaling potentials for use in future computational paradigms and artificial neural networks.
Multi-destination release of nanoparticles using an optical nanofiber assisted by a barrier
Authors: Xin Hongbao , Li Baojun
Published: March 2012

This work provides optical delivery and controllable multi-destination release of nanoparticles (NPs) using a defect-decorated optical nanofiber (NF) assisted by a barrier. The delivery and release was accurately controlled using different evanescent optical fields at different regions of the NF by changing the injected optical power. The NPs (polystyrene, 713 nm diameter) were delivered along the NF (690 nm diameter) toward the decorated defect when a laser beam at a wavelength of 980 nm was injected into the NF. At an injected optical power of 25 mW, the NPs were delivered at an average velocity of 2.9 μm/s and 90% of them were released around the barrier, which is set beside the defect. When the power was increased to 40 mW, the average delivery velocity reached 4.2 μm/s and 92% of the NPs were released at the side of the defect opposite to the barrier. By further increasing the power to 80 mW, the average delivery velocity further increased to 8.2 μm/s. Consequently, 90% of the NPs moved across the defect and were delivered to the next destination at an average velocity of 5.2 μm/s. The experimental results were then explained theoretically using numerical simulations.
Relating Carneades with abstract argumentation via the ASPIC+ framework for structured argumentation
Authors: van Gijzel Bas , Prakken Henry
Published: March 2012

Carneades is a recently proposed formalism for structured argumentation with varying proof standards, inspired by legal reasoning, but more generally applicable. Its distinctive feature is that each statement can be given its own proof standard, which is claimed to allow a more natural account of reasoning under burden of proof than existing formalisms for structured argumentation, in which proof standards are defined globally. In this article, the two formalisms are formally related by translating Carneades into the ASPIC+ framework for structured argumentation. Since ASPIC+ is defined to generate Dung-style abstract argumentation frameworks, this in effect translates Carneades graphs into abstract argumentation frameworks. For this translation, we prove a formal correspondence and show that certain rationality postulates hold. It is furthermore proved that Carneades always induces a unique Dung extension, which is the same in all of Dung's semantics, allowing us to generalise Carneades to cycle-containing structures.
Measurements of core lithium concentration in a Li-conditioned tokamak with carbon walls
Authors: Podestà M. , Bell R.E. , Diallo A. , LeBlanc B.P. , Scotti F.
Published: March 2012

The National Spherical Torus Experiment (NSTX Onoet al2000Nucl. Fusion40557) is exploring the use of lithium as candidate plasma-facing material to handle the large power flux to the wall of fusion devices. This paper reports on the measurements of lithium concentration in the plasma core during the 2010 NSTX experimental campaign, during which 1.3 kg of lithium was evaporated into the NSTX vessel. It is shown that lithium does not accumulate in significant amounts inside the plasma, resulting in an upper bound for the measured lithium concentration that is well below 0.1% of the electron density for a broad range of experimental conditions. Carbon, which constitutes the primary material of the NSTX inner wall, remains the dominant plasma impurity even after large amounts of lithium, of the order of hundreds of milligrams, are evaporated into the vacuum vessel.
The RNA-binding protein QKI5 is a direct target of C/EBPα and delays macrophage differentiation
Authors: Fu Haiyan , Yang Guodong , Wei Mengying , Liu Li , Jin Liang , Lu Xiaozhao , Wang Li , Shen Lan , Zhang Jing , Lu Huanyu , Yao Libo , Lu Zifan
Published: March 2012

Differentiated macrophages are essential for the innate immune system; however, the molecular mechanisms underlying the generation of macrophages remain largely unknown. Here we show that the RNA-binding protein QKI, mainly QKI-5, is transcriptionally activated in the early differentiated monocytic progenitors when CCAAT/enhancer-binding protein (C/EBP) α is expressed. The forced expression of C/EBPα increases the endogenous expression of QKI. Chromatin immunoprecipitation analysis and reporter assays further confirm that C/EBPα activates the transcription of QKI, primarily by binding to the distal C/EBPα-binding site. Blocking the induction of QKI using RNA interference enhances the expression of endogenous CSF1R and facilitates macrophage differentiation. Further study of the mechanism reveals that QKI-5 facilitates the degradation of CSF1R mRNA by interacting with the distal QRE in the 3′ untranslated region. In summary, we show that in committed macrophage progenitors, C/EBPα-activated QKI-5 negatively regulates macrophage differentiation by down-regulating CSF1R expression, forming a negative feedback loop during macrophage differentiation.
WIC and the Price of Infant Formula
Authors: Reed Albert J. , Levedahl J.W.
Published: March 2012

This article presents an economic model of a national infant formula market that quantifies the effects of sole‐source contracts on infant formula prices, on producer earnings, and on the taxpayer cost of providing infant formula to participants of the Special Supplemental Nutrition Program for Women, Infants, and Children. It shows that the behavior of paying customers, manufacturers, and retail stores determines the value of local sole‐source contracts to manufacturers and that this value motivates manufacturers to acquire sole‐source contracts and make rebate payments that contain the taxpayer cost of providing infant formula to program participants.
Recombinant nucleocapsid-like particles from dengue-2 induce functional serotype-specific cell-mediated immunity in mice
Authors: Gil Lázaro , Bernardo Lídice , Pavón Alequis , Izquierdo Alienys , Valdés Iris , Lazo Laura , Marcos Ernesto , Romero Yaremis , Guzmán María G. , Guillén Gerardo , Hermida Lisset
Published: March 2012

The interplay of different inflammatory cytokines induced during dengue virus infection plays a role in either protection or increased disease severity. In this sense, vaccine strategies incorporating whole virus are able to elicit both functional and pathological responses. Therefore, an ideal tetravalent vaccine candidate against dengue should be focused on serotype-specific sequences. In the present work, a new formulation of nucleocapsid-like particles (NLPs) obtained from the recombinant dengue-2 capsid protein was evaluated in mice to determine the level of protection against homologous and heterologous viral challenge and to measure the cytotoxicity and cytokine-secretion profiles induced upon heterologous viral stimulation. As a result, a significant protection rate was achieved after challenge with lethal dengue-2 virus, which was dependent on CD4+and CD8+cells. In turn, no protection was observed after heterologous challenge. In accordance,in vitro-stimulated spleen cells from mice immunized with NLPs from the four dengue serotypes showed a serotype-specific response of gamma interferon- and tumour necrosis factor alpha-secreting cells. A similar pattern was detected when spleen cells from dengue-immunized animals were stimulated with the capsid protein. Taking these data together, we can assert that NLPs constitute an attractive vaccine candidate against dengue. They induce a functional immune response mediated by CD4+and CD8+cells in mice, which is protective against viral challenge. In turn, they are potentially safe due to two important facts: induction of serotype specific cell-mediated immunity and lack of induction of antiviral antibodies. Further studies in non-human primates or humanized mice should be carried out to elucidate the usefulness of the NLPs as a potential vaccine candidate against dengue disease.
Silencing of the Rac1 GTPaseMtROP9inMedicago truncatulaStimulates Early Mycorrhizal and Oomycete Root Colonizations But Negatively Affects Rhizobial Infection
Authors: Kiirika Leonard Muriithi , Bergmann Hannah Friederike , Schikowsky Christine , Wimmer Diana , Korte Joschka , Schmitz Udo , Niehaus Karsten , Colditz Frank
Published: March 2012

RAC/ROP proteins (ρ-related GTPases of plants) are plant-specific small G proteins that function as molecular switches within elementary signal transduction pathways, including the regulation of reactive oxygen species (ROS) generation during early microbial infection via the activation of NADPH oxidase homologs of plants termed RBOH (for respiratory burst oxidase homolog). We investigated the role of Medicago truncatula Jemalong A17 small GTPase MtROP9, orthologous to Medicago sativa Rac1, via an RNA interference silencing approach. Composite M. truncatula plants (MtROP9i) whose roots have been transformed by Agrobacterium rhizogenes carrying the RNA interference vector were generated and infected with the symbiotic arbuscular mycorrhiza fungus Glomus intraradices and the rhizobial bacterium Sinorhizobium meliloti as well as with the pathogenic oomycete Aphanomyces euteiches. MtROP9i transgenic lines showed a clear growth-reduced phenotype and revealed neither ROS generation nor MtROP9 and MtRBOH gene expression after microbial infection. Coincidently, antioxidative compounds were not induced in infected MtROP9i roots, as documented by differential proteomics (two-dimensional differential gel electrophoresis). Furthermore, MtROP9 knockdown clearly promoted mycorrhizal and A. euteiches early hyphal root colonization, while rhizobial infection was clearly impaired. Infected MtROP9i roots showed, in part, extremely swollen noninfected root hairs and reduced numbers of deformed nodules. S. meliloti nodulation factor treatments of MtROP9i led to deformed root hairs showing progressed swelling of its upper regions or even of the entire root hair and spontaneous constrictions but reduced branching effects occurring only at swollen root hairs. These results suggest a key role of Rac1 GTPase MtROP9 in ROS-mediated early infection signaling.
Exploring the Complex Social Processes of Organizational Change: Supply Chain Orientation From a Manager’s Perspective
Authors: Omar Ayman , Davis‐Sramek Beth , Fugate Brian S. , Mentzer John T.
Published: March 2012

Effective supply chain management strategies can lead to substantial improvements in customer value and reductions in system wide costs for each participant. Implementing supply chain management strategies, however, is not possible without embracing supply chain orientation (SCO) as a managerial philosophy. Organizational theorists have argued that organizations change only when the people in them change, yet we know little about the complex social processes occurring in the minds of the individuals involved in creating an SCO. The current literature lacks research that describes the transition to an SCO from a supply chain manager’s perspective. Our objective is to fill this gap by delving into the minds of operations managers, who must carry out an interpretation process to set goals, process information, perceive their environment, and actively solve problems when confronted with the organization’s decision to implement supply chain initiatives. We adopt an interpretivist ontology through utilizing grounded theory to provide an in‐depth analysis of interviews from seven manufacturing organizations and 121 supply chain managers to provide a rich description of those managers’ perceptions and challenges throughout the transition. Managerial and research implications as well as future research opportunities are provided.
Logistics Service Providers and Their Customers: Gaining Commitment Through Organizational Implants
Authors: Grawe Scott J. , Daugherty Patricia J. , Dant Rajiv P.
Published: March 2012

The current research examines the following question: how can on‐site representatives (i.e., organizational implants) be used to generate greater interorganizational relationship commitment? The relationship marketing literature explores many facets of interorganizational relationships and commitment, but until now, it has not considered the colocation of employees from separate firms. Dyadic survey data were collected from logistics service providers (LSPs) and their customers. The paired dyads were then analyzed using path analysis. Results indicate that organizational implantation can lead to greater levels of outcome interdependence between the organizations, which can then generate greater levels of commitment from the LSP toward the customer. Results also suggest that organizational implantation can lead to greater levels of relational capital and responsiveness, which is shown to generate greater levels of commitment from the customer toward the LSP.
Significance of epithelial growth factor in the epithelial–mesenchymal transition of human gallbladder cancer cells
Authors: Sasaki Takamitsu , Kuniyasu Hiroki , Luo Yi , Kato Daisuke , Shinya Satoshi , Fujii Kiyomu , Ohmori Hitoshi , Yamashita Yuichi
Published: March 2012

Five gallbladder cancer (GBC) cell lines were examined for morphological changes in collagen gel culture. GBh3 and HUCCT‐1 cells formed tubules in response to treatment with epithelial growth factor (EGF) and hepatocyte growth factor (HGF), and showed high levels of expression of E‐cadherin (ECD), and low levels of SNAIL, vimentin, transforming growth factor (TGF)‐β, and nucleostemin (NS). In contrast, the GBd15 and FU‐GBC‐1 cell lines treated with EGF and HGF showed a scattering phenotype, and expressed low levels of ECD and high levels of SNAIL, vimentin, TGF‐β, and NS. All cell lines expressed the EGF receptor, c‐Met, EGF, and TGF‐α, but not HGF. Transforming growth factor‐β was upregulated by EGF. Knockdown of the EGF receptor abrogated both tubule formation and scattering, whereas KD of TGF‐β abrogated only scattering. Knockdown of EGF induced nuclear translocation of β‐catenin and Wnt‐related NS induction in the scattering cell lines, but not in the tubule‐forming cell lines, whereas KD of glycogen synthase kinase‐3β in the tubule‐forming cell lines resulted in the nuclear translocation of β‐catenin and Wnt‐related NS induction in response to EGF treatment. These results suggest that EGF enhances epithelial–mesenchymal transformation and acquisition of stemness in GBC cells with a scattering phenotype through the activity of β‐catenin. Repression of ECD in scattering GBC cells induced the release of β‐catenin from the cell adhesion complexes along the plasma membrane and its translocation to the nucleus to activate Wnt signaling, which upregulated NS. (Cancer Sci 2012; 103: 1165–1171)
Low expression of RECK indicates a shorter survival for patients with invasive breast cancer
Authors: Zhang Yue , Cheng Shaoqiang , Zhang Guoqiang , Ma Wenjie , Liu Yang , Zhao Rui , Zhang Qingyuan , Pang Da
Published: March 2012

Expression cloning was used to initially isolate the reversion‐inducing cysteine‐rich protein with Kazal motifs (RECK) gene as a suppressor of transformation. The gene was found to encode a membrane‐anchored regulator of MMPs. Experimental studies showed that RECK can suppress tumor invasion, metastasis, and angiogenesis. However, the clinical impact of RECK remains unclear. To assess the clinical significance of RECK expression in invasive breast cancer, a total of 119 patients with invasive breast cancer were retrospectively examined. Expression of RECK in tumor tissues was assessed by immunohistochemical staining. A significant correlation between RECK expression and 5‐year survival rate was documented. The 5‐year survival rate for patients with strong RECK expression was significantly higher than that for patients with weakly expressing tumors. Univariate and multivariate analyses confirmed that reduced RECK expression was an independent and significant factor in predicting a poor prognosis. In conclusion, RECK expression is a significant prognostic factor correlated with long‐term survival for patients with invasive breast cancer. RECK expression is therefore a potentially useful prognostic marker for breast cancer. (Cancer Sci 2012; 103: 1084–1089)
Engaging fathers in child welfare services: a narrative review of recent research evidence
Authors: Maxwell Nina , Scourfield Jonathan , Featherstone Brid , Holland Sally , Tolman Richard
Published: March 2012

It is widely recognized as problematic that there are generally low levels of engagement with child welfare services from biological and social fathers. The result can be limited resources for children's care and potentially poor risk assessment and management. This paper reviews the published research from 2000 to 2010 about the barriers to and facilitators of better father engagement, as well as the very limited evidence on the effectiveness of work with maltreating fathers. There is relatively little known about what works in engaging men, but there are some promising indicators from family support and child protection practice contexts. These include early identification and early involvement of fathers; a proactive approach, including an insistence on men's involvement with services; and the use of practical activities. In the light of what is known about the characteristics of maltreating fathers, there is a logical fit with cognitive‐behavioural approaches. Although there is no direct evidence of the effectiveness of motivational interviewing in this context, its effectiveness in allied fields of practice would suggest that it may hold some promise for the initial engagement of fathers who pose a risk to children.
The role of seasonal grass pollen on childhood asthma emergency department presentations
Authors: Erbas B. , Akram M. , Dharmage S. C. , Tham R. , Dennekamp M. , Newbigin E. , Taylor P. , Tang M. L. K. , Abramson M. J.
Published: March 2012

Background

Few studies have focused on the role of grass pollen on asthma emergency department (ED) presentations among children. None have examined whether a dose‐response effect exists between grass pollen levels and these asthma exacerbations.

Objectives

To examine the association between increasing ambient levels of grass pollen and asthma ED presentations in children. To determine whether these associations are seen only after a thunderstorm, or whether grass pollen levels have a consistent influence on childhood asthma ED visits during the season.

Methods

A short time series ecological study was conducted for asthma presentations to ED among children in Melbourne, Victoria, and grass pollen, meteorological and air quality measurements recorded during the selected 2003 period. A semi‐parametric Poisson regression model was used to examine dose‐response associations between daily grass pollen levels and mean daily ED attendance for asthma.

Results

A smoothed plot suggested a dose‐response association. As ambient grass pollen increased to about 19 grains/m3, the same day risk of childhood ED presentations also increased linearly (P < 0.001). Grass pollen levels were also associated with an increased risk in asthma ED presentations on the following day (lag 1, P < 0.001).

Conclusion

This is the first study to establish a clear relationship between increased risk of childhood asthma ED attendance and levels of ambient grass pollen below 20 grains/m3, independent of any impact of thunderstorm‐associated asthma. These findings have important implications for patient care, such as asthma management programs that notify the general public regarding periods of high grass pollen exposure, as well as defining the timing of initiation of pollen immunotherapy.
Fetal growth and risk of childhood asthma and allergic disease
Authors: Tedner S. G. , Örtqvist A. K. , Almqvist C.
Published: March 2012

Introduction

Early genetic and environmental factors have been discussed as potential causes for the high prevalence of asthma and allergic disease in the western world, and knowledge on fetal growth and its consequence on future health and disease development is emerging.

Objective

This review article is an attempt to summarize research on fetal growth and risk of asthma and allergic disease. Current knowledge and novel findings will be reviewed and open research questions identified, to give basic scientists, immunologists and clinicians an overview of an emerging research field.

Methods

PubMed‐search on pre‐defined terms and cross‐references.

Results

Several studies have shown a correlation between low birth weight and/or gestational age and asthma and high birth weight and/or gestational age and atopy. The exact mechanism is not yet clear but both environmental and genetic factors seem to contribute to fetal growth. Some of these factors are confounders that can be adjusted for, and twin studies have been very helpful in this context. Suggested mechanisms behind fetal growth are often linked to the feto‐maternal circulation, including the development of placenta and umbilical cord. However, the causal link between fetal growth restriction and subsequent asthma and allergic disease remains unexplained. New research regarding the catch‐up growth following growth restriction has posited an alternative theory that diseases later on in life result from rapid catch‐up growth rather than intrauterine growth restrictionper se. Several studies have found a correlation between a rapid weight gain after birth and development of asthma or wheezing in childhood.

Conclusion and clinical relevance

Asthma and allergic disease are multifactorial. Several mechanisms seem to influence their development. Additional studies are needed before we fully understand the causal links between fetal growth and development of asthma and allergic diseases.
Hairless mutation: a driving force of humanization from a human–ape common ancestor by enforcing upright walking while holding a baby with both hands
Authors: Sutou Shizuyo
Published: March 2012

Three major characteristics distinguish humans from other primates: bipedality, practical nakedness, and the family as a social unit. A hairless mutation introduced into the chimpanzee/human last common ancestor (CLCA) 6 million years ago (Mya) diverged hairless human and hairy chimpanzee lineages. All primates except humans can carry their babies without using their hands. A hairless mother would be forced to stand and walk upright. Her activities would be markedly limited. The male partner would have to collect food and carry it to her by hand to keep her and their baby from starving; irresponsible and selfish males could not have left their offspring. The mother would have sexually accepted her partner at any time as a reward for food. Sexual relations irrespective of estrus cycles might have strengthened the pair bond. Molecular and paleontological dating indicates that CLCA existed 6 Mya, and early hominin fossils show that they were bipeds, indicating that humanization from CLCA occurred rapidly. A single mutation in animals with scalp hair is known to induce hairless phenotype (ectodermal dysplasia). Bipedalism and hairlessness are disadvantageous traits; only those who could survive trials and tribulations in cooperation with family members must have been able to evolve as humans.
Analytical wavefront curvature correction to plane‐wave reflection coefficients for a weak‐contrast interface
Authors: Alulaiw Badr , Gurevich Boris
Published: March 2012

Most amplitude versus offset (AVO) analysis and inversion techniques are based on the Zoeppritz equations for plane‐wave reflection coefficients or their approximations. Real seismic surveys use localized sources that produce spherical waves, rather than plane waves. In the far‐field, the AVO response for a spherical wave reflected from a plane interface can be well approximated by a plane‐wave response. However this approximation breaks down in the vicinity of the critical angle. Conventional AVO analysis ignores this problem and always utilizes the plane‐wave response. This approach is sufficiently accurate as long as the angles of incidence are much smaller than the critical angle. Such moderate angles are more than sufficient for the standard estimation of the AVO intercept and gradient. However, when independent estimation of the formation density is required, it may be important to use large incidence angles close to the critical angle, where spherical wave effects become important. For the amplitude of a spherical wave reflected from a plane fluid‐fluid interface, an analytical approximation is known, which provides a correction to the plane‐wave reflection coefficients for all angles. For the amplitude of a spherical wave reflected from a solid/solid interface, we propose a formula that combines this analytical approximation with the linearized plane‐wave AVO equation. The proposed approximation shows reasonable agreement with numerical simulations for a range of frequencies. Using this solution, we constructed a two‐layer three‐parameter least‐squares inversion algorithm. Application of this algorithm to synthetic data for a single plane interface shows an improvement compared to the use of plane‐wave reflection coefficients.
Retrospective evaluation of bleeding tendency and simultaneous thrombin and plasmin generation in patients with rare bleeding disorders
Authors: Van GEFFEN M. , MENEGATTI M. , LOOF A. , LAP P. , KARIMI M. , LAROS‐van GORKOM B. A. P. , BRONS P. , Van HEERDE W. L.
Published: March 2012

Summary.  Rare bleeding disorders (RBDs) are a heterogeneous group of diseases with varying bleeding tendency, only partially explained by their laboratory phenotype. We analysed the separate groups of RBD abnormalities, and we investigated retrospectively whether the novel haemostasis assay (NHA) was able to differentiate between bleeding tendency. We have performed simultaneous thrombin generation (TG) and plasmin generation (PG) measurements in 41 patients affected with deficiencies in prothrombin, factor (F) V, FVII, FX, FXIII and fibrinogen. Parameters of the NHA were classified based on (major or minor) bleeding tendency. Patients with deficiencies in coagulation propagation (FII, FV and FX) and major type of bleedings had diminished TG (expressed as AUC) below 20% of control. FVII deficient patients only had prolonged thrombin lag‐time ratio of 1.6 ± 0.2 (P < 0.05) and normal AUC (92–125%). Afibrinogenemic patients demonstrated PG of 2–29% of normal and appeared to correlate with the type of mutation. Thrombin peak‐height (57 ± 16%) was reduced (not significant) in these patients and AUC was comparable to the reference (102 ± 27%). FXIII‐deficient plasmas resulted in a reduced thrombin peak‐height of 59 ± 13% (P < 0.05) and normal AUC (90 ± 14%). Thrombin peak‐height (P < 0.01) and plasmin potential (P < 0.05) were lower in the major bleeders compared with the minor bleeders. These results provided distinct TG and PG curves for each individual abnormality and differentiation of bleeding tendency was observed for thrombin and PG parameters. Prospective studies are warranted to confirm these retrospective results.
Amino acid profile, protein digestibility, thermal and functional properties of Conophor nut (Tetracarpidium conophorum) defatted flour, protein concentrate and isolates
Authors: Gbadamosi Saka O. , Abiose Sumbo H. , Aluko Rotimi E.
Published: March 2012

Functional properties, amino acid compositions, in vitro protein digestibility, electrophoretic and thermal characteristics of conophor defatted flour (CDF), conophor protein concentrate (CPC), isoelectric protein isolate (CII) and neutral protein isolate (CNI) were evaluated. The isolates (CII and CNI) showed significantly lower (P < 0.05) water and oil absorption capacities, emulsifying and gelling capacities, but higher emulsion stability and foaming capacity. In vitro protein digestibility, enthalpy and denaturation temperature varied between 52.28% and 73.4%, 1.62–4.04 J g−1 protein and 79.7–89.3 °C, respectively. The native proteins were comprised of subunits with molecular weights ranging between 15.3 and 129.3 kDa. The major amino acids in all the samples were aspartic acid, glutamic acid and arginine, whereas the percentages of essential amino acids in CDF, CPC, CII and CNI were 39.35%, 40.46%, 44.54% and 46.04%, respectively. Conophor protein products could be used as functional ingredients in food formulations and for enriching low quality protein diets.