bluuebunny/crossref_metadata_2025 huggingface dataset:
Powers of the Likelihood Ratio Test and the Correlation Test Using Empirical Bayes Estimates for Various Shrinkages in Population Pharmacokinetics
Authors: Combes FP , Retout S , Frey N , Mentré F
Published: April 2014

We compared the powers of the likelihood ratio test (LRT) and the Pearson correlation test (CT) from empirical Bayes estimates (EBEs) for various designs and shrinkages in the context of nonlinear mixed‐effect modeling. Clinical trial simulation was performed with a simple pharmacokinetic model with various weight (WT) effects on volume (V). Data sets were analyzed with NONMEM 7.2 using first‐order conditional estimation with interaction and stochastic approximation expectation maximization algorithms. The powers of LRT and CT in detecting the link between individual WT and V or clearance were computed to explore hidden or induced correlations, respectively. Although the different designs and variabilities could be related to the large shrinkage of the EBEs, type 1 errors and powers were similar in LRT and CT in all cases. Power was mostly influenced by covariate effect size and, to a lesser extent, by the informativeness of the design. Further studies with more models are needed.

CPT Pharmacometrics Syst. Pharmacol. (2014) 4, e109; doi:10.1038/psp.2014.5; published online 9 April 2014
Oral administration of Lactobacillus gasseri SBT2055 is effective for preventing influenza in mice
Authors: Nakayama Yosuke , Moriya Tomohiro , Sakai Fumihiko , Ikeda Noriko , Shiozaki Takuya , Hosoya Tomohiro , Nakagawa Hisako , Miyazaki Tadaaki
Published: April 2014

The Lactobacillus gasseri SBT2055 (LG2055) is a probiotic lactic acid bacterium with properties such as bile tolerance and ability to improve the intestinal environment. In this study, we established that the oral administration of LG2055 exhibits efficacy to protect mice infected with the influenza virus A/PR8. The body weight losses were lower with the LG2055 administration after the PR8 virus infection. At 5 days after the infection, the virus titer was significantly decreased as was the amount of produced IL-6 in the lung tissue, the number of total cells in the bronchoalveolar lavage fluid was reduced by the LG2055 administration. The expression of the Mx1 and Oas1a genes, critical for the viral clearance in the lung tissues was increased by the pre-treatment with LG2055. These findings suggest that the LG2055 administration is effective for the protection against influenza A virus infection by the down-regulation of viral replication through the induction of antiviral genes expression.
An ultra-high-throughput spiral microfluidic biochip for the enrichment of circulating tumor cells
Authors: Warkiani Majid Ebrahimi , Khoo Bee Luan , Tan Daniel Shao-Weng , Bhagat Ali Asgar S. , Lim Wan-Teck , Yap Yoon Sim , Lee Soo Chin , Soo Ross A. , Han Jongyoon , Lim Chwee Teck
Published: April 2014

We demonstrate the high-throughput and high-resolution separation of rare circulating tumor cells (CTCs) from blood using a multiplexed spiral microfluidic device.
A sequential solid phase microextraction system coupled with inductively coupled plasma mass spectrometry for speciation of inorganic arsenic
Authors: Li Peng , Zhang Xiao-qin , Chen Yi-jun , Lian Hong-zhen , Hu Xin
Published: April 2014

A sequential solid phase microextraction (SPME) system consisting of two monolithic capillary columns was developed for simultaneous separation and preconcentration of inorganic arsenic, followed by inductively coupled plasma mass spectrometry (ICP-MS) detection.
Development of a direct competitive chemiluminescent ELISA for the detection of nitrofurantoin metabolite 1-amino-hydantoin in fish and honey
Authors: Wang Quan , Liu Ying-Chun , Chen Yong-Jun , Jiang Wei , Shi Jin-Lei , Xiao Yan , Zhang Meng
Published: April 2014

A direct competitive enzyme-linked immunosorbent assay (ELISA) with chemiluminescent (dcCLELISA) detection for 1-amino-hydantoin (AHD) was developed in this study.
Effect of ozone exposure on the electrical characteristics of high-purity, large-diameter semiconducting carbon nanotubes
Authors: Gao Jia , Loo Yueh-Lin
Published: April 2014

Presorted, semiconducting carbon nanotubes in the channels of field-effect transistors undergo simultaneous p-doping and oxidation during ozone exposure.
Quaternization and oxidation reactions of cyclodiphosphazane derivatives and their copper(i) and gold(i) complexes
Authors: Balakrishna Maravanji S. , Suresh Devarajan , Ananthnag Guddekoppa S. , Mague Joel T.
Published: April 2014

Quaternization reactions of various cyclodiphosphazanes and their transition metal (CuI and AuI) complexes are described.
Hierarchical CoNiO2structures assembled from mesoporous nanosheets with tunable porosity and their application as lithium-ion battery electrodes
Authors: Liu Yanguo , Zhao Yanyan , Yu Yanlong , Li Jinpeng , Ahmad Mashkoor , Sun Hongyu
Published: April 2014

Mesoporous CoNiO2structures can be considered as alternative materials for application in the design of energy storage devices.
Intramolecular C–H⋯F hydrogen bonding-induced 1,2,3-triazole-based foldamers
Authors: Liu Yan-Hua , Zhang Liang , Xu Xiao-Na , Li Zhi-Ming , Zhang Dan-Wei , Zhao Xin , Li Zhan-Ting
Published: April 2014

Intramolecular C–H⋯F hydrogen bonding has been utilized to induce 1,2,3-triazole oligomers to fold into stable artificial secondary structures.
A CO2fixation process with waste cement powder via regeneration of alkali and acid by electrodialysis
Authors: Shuto Daiki , Nagasawa Hiroki , Iizuka Atsushi , Yamasaki Akihiro
Published: April 2014

A mineral carbonation process for CO2sequestration has been developed, and its process feasibility was examined based on laboratory-scale experimental studies.
Effect of graphene nanosheets and layered double hydroxides on the flame retardancy and thermal degradation of epoxy resin
Authors: Liu Shan , Yan Hongqiang , Fang Zhengping , Guo Zhenghong , Wang Hao
Published: April 2014

Graphene nanosheets and layered double hydroxides showed a synergistic effect on improving the flame retardancy of epoxy resin.
A cytochrome C encapsulated metal organic framework as a bio-material for sulfate ion recognition
Authors: Rambabu Darsi , Pooja Pooja , Pradeep Chullikkattil P. , Dhir Abhimanew
Published: April 2014

An ensemble of a cytochrome c and 2,6-naphthalene dicarboxylate based metal organic framework is synthesized. The bio-material selectively senses sulfate ions in 100% aqueous solution.
Gold nanoparticles and gold nanoparticle-conjugates for delivery of therapeutic molecules. Progress and challenges
Authors: Fratoddi I. , Venditti I. , Cametti C. , Russo M. V.
Published: April 2014

Gold nanoparticles and their conjugates as drug delivery vehicles for selective targeting of cancer cells.
Regulation of 5-oxo-ETE synthesis by nitric oxide in human polymorphonuclear leucocytes upon their interaction with zymosan andSalmonella typhimurium
Authors: Viryasova Galina M. , Galkina Svetlana I. , Gaponova Tatjana V. , Romanova Julia M. , Sud’ina Galina F.
Published: April 2014

In the present study we have presented data on the regulation of LT (leukotriene) and 5-oxo-ETE (5-oxo-6,8,11,14-eicosatetraenoic acid) syntheses in human neutrophils upon interaction with OZ (opsonized zymosan) or Salmonella typhimurium. Priming of neutrophils with PMA (phorbol 12-myristate 13-acetate) and LPS (lipopolysaccharide) elicits 5-oxo-ETE formation in neutrophils exposed to OZ, and the addition of AA (arachidonic acid) significantly increases 5-oxo-ETE synthesis. We found that NO (nitric oxide)-releasing compounds induce 5-oxo-ETE synthesis in neutrophils treated with OZ or S. typhimurium. Exposure of neutrophils to zymosan or bacteria in the presence of the NO donor DEA NONOate (1,1-diethyl-2-hydroxy-2-nitroso-hydrazine sodium) considerably increased the conversion of endogenously formed 5-HETE (5S-hydroxy-6,8,11,14-eicosatetraenoic acid) to 5-oxo-ETE. To our knowledge, this study is the first to demonstrate that NO is a potent regulator of 5-oxo-ETE synthesis in human polymorphonuclear leucocytes exposed to Salmonella typhimurium and zymosan.
Omega transmission lines with applications to effective medium models of metamaterials
Authors: Vehmas J. , Hrabar S. , Tretyakov S.
Published: April 2014

In this paper, we introduce the concept of transmission lines with inherent bi-anisotropy and establish an analogy between these lines and volumetric bi-anisotropic materials. In particular, we find under what conditions a periodically loaded transmission line can be treated as an effective omega medium. Two example circuits are introduced and analyzed. The results have two-fold implications: opening a route to emulate electromagnetic properties of bi-anisotropic omega media using transmission-line meshes and understanding and improving effective medium models of composite materials with the use of effective circuit models of unit cells.
An instability of hyperbolic space under the Yang-Mills flow
Authors: Gegenberg Jack , Day Andrew C. , Liu Haitao , Seahra Sanjeev S.
Published: April 2014

We consider the Yang-Mills flow on hyperbolic 3-space. The gauge connection is constructed from the frame-field and (not necessarily compatible) spin connection components. The fixed points of this flow include zero Yang-Mills curvature configurations, for which the spin connection has zero torsion and the associated Riemannian geometry is one of constant curvature. We analytically solve the linearized flow equations for a large class of perturbations to the fixed point corresponding to hyperbolic 3-space. These can be expressed as a linear superposition of distinct modes, some of which are exponentially growing along the flow. The growing modes imply the divergence of the (gauge invariant) perturbative torsion for a wide class of initial data, indicating an instability of the background geometry that we confirm with numeric simulations in the partially compactified case. There are stable modes with zero torsion, but all the unstable modes are torsion-full. This leads us to speculate that the instability is induced by the torsion degrees of freedom present in the Yang-Mills flow.
Mode 1 drive asymmetry in inertial confinement fusion implosions on the National Ignition Facility
Authors: Spears Brian K. , Edwards M. J. , Hatchett S. , Kilkenny J. , Knauer J. , Kritcher A. , Lindl J. , Munro D. , Patel P. , Robey H. F. , Town R. P. J.
Published: April 2014

Mode 1 radiation drive asymmetry (pole-to-pole imbalance) at significant levels can have a large impact on inertial confinement fusion implosions at the National Ignition Facility (NIF). This asymmetry distorts the cold confining shell and drives a high-speed jet through the hot spot. The perturbed hot spot shows increased residual kinetic energy and reduced internal energy, and it achieves reduced pressure and neutron yield. The altered implosion physics manifests itself in observable diagnostic signatures, especially the neutron spectrum which can be used to measure the neutron-weighted flow velocity, apparent ion temperature, and neutron downscattering. Numerical simulations of implosions with mode 1 asymmetry show that the resultant simulated diagnostic signatures are moved toward the values observed in many NIF experiments. The diagnostic output can also be used to build a set of integrated implosion performance metrics. The metrics indicate that P1 has a significant impact on implosion performance and must be carefully controlled in NIF implosions.
Non-volatile magnetoelectric edge effects observed using magnetic force microscopy
Authors: Ghidini M. , Pellicelli R. , Mathur N. D.
Published: April 2014

In BaTiO3-based multilayer capacitors (MLCs) that show volatile magnetoelectric (ME) effects [C. Israel et al., Appl. Phys. Lett. 93, 173501 (2008)], a magnetic force microscopy study of the Ni electrode edges reveals non-volatile ME effects, due to the inhomogenous stress associated with an electric-field distribution that we model using finite-element analysis. Our findings imply that volatile ME effects in thin films may be rendered non-volatile by lithographic patterning, thus suggesting a route for the design of electric-write magnetic-read data-storage elements.
Nonlinear simplified model to study localization of kinetic Alfvén wave
Authors: Sharma R. P. , Gaur Nidhi
Published: April 2014

We have presented the numerical simulation of the coupled equations governing the dynamics of kinetic Alfvén wave (KAW) and ion acoustic wave in the intermediate β plasma, where β is the ratio of thermal pressure to the background magnetic pressure. We have also developed a simplified model for this nonlinear interaction using the results obtained from the simulation to understand the physics of nonlinear evolution of KAW. Localization of magnetic field intensity of KAW has been studied by means of the simplified model.
Improving the conversion efficiency of Cu2ZnSnS4 solar cell by low pressure sulfurization
Authors: Zhang Kun , Su Zhenghua , Zhao Lianbo , Yan Chang , Liu Fangyang , Cui Hongtao , Hao Xiaojing , Liu Yexiang
Published: April 2014

Cu2ZnSnS4 thin films have been prepared by the sol-gel sulfurization method on Mo-coated substrates, and the comparative studies between the atmospheric pressure sulfurization and low pressure sulfurization was carried out. The Cu2ZnSnS4 film sulfurized at low pressure exhibits larger grain size, thinner MoS2 layer, and free of SnS secondary phase, but more ZnS on surface. The device efficiency of 4.1% using Cu2ZnSnS4 absorber from atmospheric pressure sulfurization is improved to 5.7% using that from low pressure sulfurization via the boost of open-circuit and fill factor.
Interface-induced magnetic coupling in multiferroic/ferromagnetic bilayer: An ultrafast pump-probe study
Authors: La-o-vorakiat C. , Tian Y. , Wu T. , Panagopoulos C. , Zhu J.-X. , Su Haibin , Chia Elbert E. M.
Published: April 2014

By use of optical pump-probe measurement, we study the relaxation dynamics of a multiferroic-ferromagnetic TbMnO3/La0.7Sr0.3MnO3 bilayer. The relaxation dynamics of both layers are well separated in time allowing us to investigate the magnetic coupling across the bilayer. We observe that the relaxation dynamics of the individual layers in the bilayer sample are the result of the interplay between the intrinsic magnetic order and the induced interfacial effect. Our data suggest the existence of induced ferromagnetic order in the TbMnO3 layer and antiferromagnetic order in the La0.7Sr0.3MnO3 layer.
Galilei invariant technique for quantum system description
Authors: Kamuntavičius Gintautas P.
Published: April 2014

Problems with quantum systems models, violating Galilei invariance are examined. The method for arbitrary non-relativistic quantum system Galilei invariant wave function construction, applying a modified basis where center-of-mass excitations have been removed before Hamiltonian matrix diagonalization, is developed. For identical fermion system, the Galilei invariant wave function can be obtained while applying conventional antisymmetrization methods of wave functions, dependent on single particle spatial variables.
Formation of p-n-p junction with ionic liquid gate in graphene
Authors: He Xin , Tang Ning , Gao Li , Duan Junxi , Zhang Yuewei , Lu Fangchao , Xu Fujun , Wang Xinqiang , Yang Xuelin , Ge Weikun , Shen Bo
Published: April 2014

Ionic liquid gating is a technique which is much more efficient than solid gating to tune carrier density. To observe the electronic properties of such a highly doped graphene device, a top gate made of ionic liquid has been used. By sweeping both the top and back gate voltage, a p-n-p junction has been created. The mechanism of forming the p-n-p junction has been discussed. Tuning the carrier density by ionic liquid gate can be an efficient method to be used in flexible electronics.
Layer-by-layer charging in non-volatile memory devices using embedded sub-2 nm platinum nanoparticles
Authors: Ramalingam Balavinayagam , Zheng Haisheng , Gangopadhyay Shubhra
Published: April 2014

In this work, we demonstrate multi-level operation of a non-volatile memory metal oxide semiconductor capacitor by controlled layer-by-layer charging of platinum nanoparticle (PtNP) floating gate devices with defined gate voltage bias ranges. The device consists of two layers of ultra-fine, sub-2 nm PtNPs integrated between Al2O3 tunneling and separation layers. PtNP size and interparticle distance were varied to control the particle self-capacitance and associated Coulomb charging energy. Likewise, the tunneling layer thicknesses were also varied to control electron tunneling to the first and second PtNP layers. The final device configuration with optimal charging behavior and multi-level programming was attained with a 3 nm Al2O3 initial tunneling layer, initial PtNP layer with particle size 0.54 ± 0.12 nm and interparticle distance 4.65 ± 2.09 nm, 3 nm Al2O3 layer to separate the PtNP layers, and second particle layer with 1.11 ± 0.28 nm PtNP size and interparticle distance 2.75 ± 1.05 nm. In this device, the memory window of the first PtNP layer saturated over a programming bias range of 7 V to 14 V, after which the second PtNP layer starts charging, exhibiting a multi-step memory window with layer-by-layer charging.
Temporally and spatially resolved characterization of microwave induced argon plasmas: Experiment and modeling
Authors: Baeva M. , Andrasch M. , Ehlbeck J. , Loffhagen D. , Weltmann K.-D.
Published: April 2014

Experiments and modeling of the plasma-microwave interaction have been performed in a coaxial microwave plasma source at a field frequency of 2.45 GHz generating argon plasmas at pressures of 20 and 40 millibars and a ratio of flow rate to pressure of 0.125 sccm/Pa. The incident microwave power between 100 W and 300 W is supplied in a regime of a pulse-width modulation with cycle duration of 110 ms and a power-on time of 23 ms. The experiments are based on heterodyne reflectometry and microwave interferometry at 45.75 GHz. They provide the temporal behaviour of the complex reflection coefficient, the microwave power in the plasma, as well as the electron density in the afterglow zone of the discharge. The self-consistent spatially two-dimensional and time-dependent modeling complements the analysis of the plasma-microwave interaction delivering the plasma and electromagnetic field parameters. The consolidating experimental observations and model predictions allow further characterizing the plasma source. The generated plasma has a core occupying the region close to the end of the inner electrode, where maximum electron densities above 1020 m−3 and electron temperatures of about 1 eV are observed. Due to a longer outer electrode of the coaxial structure, the plasma region is extended and fills the volume comprised by the outer electrode. The electron density reaches values of the order of 1019 m−3. The heating of the gas occurs in its great part due to elastic collisions with the plasma electrons. However, the contribution of the convective heating is important especially in the extended plasma region, where the gas temperature reaches its maximum values up to approximately 1400 K. The temporally and spatially resolved modeling enables a thorough investigation of the plasma-microwave interaction which clearly shows that the power in-coupling occurs in the region of the highest electron density during the early stage of the discharge. In the steady state phase, however, the power in-coupling occurs close to the source walls where the electron density is significantly lower than on the discharge axis.
Increased carbon nanotube area density after catalyst generation from cobalt disilicide using a cyclic reactive ion etching approach
Authors: Xie Rongsi , Zhang Can , Chen Bingan , van der Veen Marleen , Zhong Guofang , Robertson John
Published: April 2014

We used a cyclic reactive ion etching (RIE) process to increase the Co catalyst density on a cobalt disilicide (CoSi2) substrate for carbon nanotube (CNT) growth. Each cycle of catalyst formation consists of a room temperature RIE step and an annealing step at 450 °C. The RIE step transfers the top-surface of CoSi2 into cobalt fluoride; while the annealing reduces the fluoride into metallic Co nanoparticles. We have optimized this cyclic RIE process and determined that the catalyst density can be doubled in three cycles, resulting in a final CNT shell density of 6.6 × 1011 walls·cm−2. This work demonstrates a very effective approach to increase the CNT density grown directly on silicides.
Relaxation times of the two-phonon processes with spin-flip and spin-conserving in quantum dots
Authors: Wang Zi-Wu , Liu Lei , Li Shu-Shen
Published: April 2014

We perform a theoretical investigation on the two-phonon processes of the spin-flip and spin-conserving relaxation in quantum dots in the frame of the Huang-Rhys' lattice relaxation model. We find that the relaxation time of the spin-flip is two orders of magnitude longer than that of the spin-conserving, which is in agreement with previous experimental measurements. Moreover, the opposite variational trends of the relaxation time as a function of the energy separation for two-phonon processes are obtained in different temperature regime. The relaxation times display the oscillatory behaviors at the demarcation point with increasing magnetic field, where the energy separation matches the optical phonon energy and results in the optical phonon resonance. These results are useful in understanding the intraband levels' relaxation in quantum dots and could be helpful in designing photoelectric and spin-memory devices
Interplay between strain, quantum confinement, and ferromagnetism in strained ferromagnetic semiconductor (In,Fe)As thin films
Authors: Sasaki Daisuke , Anh Le Duc , Nam Hai Pham , Tanaka Masaaki
Published: April 2014

We systematically investigated the influence of strain on the electronic structure and ferromagnetism of (In,Fe)As thin films. It is found that while the shift of the critical point energies of compressive-strained (In,Fe)As layers grown on (In1−y,Gay)As (y = 0.05, 0.1) buffer layers can be explained by the hydrostatic deformation effect (HDE) alone, those of tensile-strained (In,Fe)As layers grown on (Ga1−z,Alz)Sb (z = 0, 0.5, 1) buffer layers can be explained by the combination of HDE and the quantum confinement effect (QCE). The Curie temperature TC of the (In,Fe)As layers strongly depends on the strain, and shows a maximum for the (In,Fe)As layer grown on a GaSb buffer layer. The strain dependence of TC can be explained by the s-d exchange mechanism taking into account HDE and QCE.
Graphene nanoribbon molecular sensor based on inelastic transport
Authors: Ritter C. , Muniz R. B. , Latgé A.
Published: April 2014

Results of phonon-assisted inelastic quantum transport calculations are presented for graphene nanoribbons. We consider a single molecule attached to a carbon atom and describe the electronic structure by a tight-binding model, taking into account a local phonon mode associated with the attached molecule characteristic vibration. The calculated transmission spectra reveal a striking sensitivity for molecules attached to the edges of asymmetric zigzag graphene nanoribbons. Our results show that the differential conductance may be used to identify the presence as well as the characteristic vibration frequency of a target molecule at finite temperatures.
Probing nonlinear magnetization dynamics in Fe/MgO(001) film by all optical pump-probe technique
Authors: He Wei , Hu Bo , Zhan Qing-Feng , Zhang Xiang-Qun , Cheng Zhao-Hua
Published: April 2014

An all-optical pump-probe technique has been employed to investigate the nonlinear magnetization dynamics of a 10 nm Fe/MgO(001) thin film in time domain. The magnetization precession was excited by pump-laser pulses and modulated by laser fluence variations. With increasing the laser fluence up to 7.1 mJ/cm2, in addition to the uniform precession mode, a second harmonic signal was detected. The time evolution of the second harmonic signal was obtained in time-frequency domain. Based on the Landau-Lifshitz-Gilbert equation, the numerical simulation was performed to reproduce the observed the frequency doubling behaviors in Fe/MgO(001) film.
High-k dielectrics on (100) and (110) n-InAs: Physical and electrical characterizations
Authors: Wang C. H. , Doornbos G. , Astromskas G. , Vellianitis G. , Oxland R. , Holland M. C. , Huang M. L. , Lin C. H. , Hsieh C. H. , Chang Y. S. , Lee T. L. , Chen Y. Y. , Ramvall P. , Lind E. , Hsu W. C. , Wernersson L.-E. , Droopad R. , Passlack M. , Diaz C. H.
Published: April 2014

Two high-k dielectric materials (Al2O3 and HfO2) were deposited on n-type (100) and (110) InAs surface orientations to investigate physical properties of the oxide/semiconductor interfaces and the interface trap density (Dit). X-ray photoelectron spectroscopy analyses (XPS) for native oxides of (100) and (110) as-grown n-InAs epi wafers show an increase in As-oxide on the (100) surface and an increase in InOx on the (110) surface. In addition, XPS analyses of high-k (Al2O3 and HfO2) on n-InAs epi show that the intrinsic native oxide difference between (100) and (110) epi surfaces were eliminated by applying conventional in-situ pre-treatment (TriMethyAluminium (TMA)) before the high-k deposition. The capacitance-voltage (C-V) characterization of HfO2 and Al2O3 MOSCAPs on both types of n-InAs surfaces shows very similar C-V curves. The interface trap density (Dit) profiles show Dit minima of 6.1 × 1012/6.5 × 1012 and 6.6 × 1012/7.3 × 1012 cm−2 eV−1 for Al2O3 and HfO2, respectively for (100) and (110) InAs surfaces. The similar interface trap density (Dit) on (100) and (110) surface orientation were observed, which is beneficial to future InAs FinFET device with both (100) and (110) surface channel orientations present.
Time-varying transistor-based metamaterial for tunability, mixing, and efficient phase conjugation
Authors: Katko Alexander R. , Barrett John P. , Cummer Steven A.
Published: April 2014

We present a transistor-based microwave metamaterial exhibiting tunability over a wide range of time scales. By loading a metamaterial with a transistor, we show through theory and simulation that both the resonant frequency and quality factor of the metamaterial can be dynamically tuned with a voltage bias. We demonstrate through experiment that such a time-varying transistor-based metamaterial exhibits this tunability. The tunability is applicable to a wide range of time scales, from quasi-static effective parameter tuning to parametric pumping for mixing and phase conjugation. We then apply the metamaterial to a particular application of phase conjugation and demonstrate through simulation and experiment that a very strong phase conjugated signal is produced. We experimentally show that the mixing efficiency for a transistor metamaterial is over 30 dB stronger than that of a varactor-based phase conjugate metamaterial.
Testing for ‘threads’ and leucocyte esterase in first-void urine to exclude the diagnosis of non-specific urethritis in asymptomatic men
Authors: Pallawela Sanjeeva N. S. , Sonnex Christopher , Burdett Julia , Cooper Dawn , Nethercott Katrina , Thomas Catherina M. , Goon Peter , Webb Hayley , Carne Christopher
Published: April 2014

Recent evidence suggests that asymptomatic nonspecific urethritis (NSU), which is not routinely tested for, is a clinically significant pathology.The aim of this pilot study was to determine if testing for urinary threads, leucocyte esterase (LE) or both in asymptomatic men is a good screening tool for NSU. Of the126 asymptomatic men, 8% met microscopic criteria for the diagnosis of NSU. The positive predictive value for NSU was 71% (95% confidence interval (CI): 29.3–95.5%) and the negative predictive value was 96% (95% CI: 92.8–99.5%). The absence of threads and negative LE makes urethritis highly unlikely, making urinary chlamydia (Chlamydia trachomatis) and gonorrhoea (Neisseria gonorrhoeae) testing sufficient. Incidental findings of further pathology occurred in 7%.
The
Caenorhabditis elegans
HP1 family protein HPL-2 maintains ER homeostasis through the UPR and hormesis
Authors: Kozlowski Lucie , Garvis Steve , Bedet Cécile , Palladino Francesca
Published: April 2014

Significance

Organisms must be able to respond quickly to stress to maintain homeostasis and survive. Perturbation of normal endoplasmic reticulum (ER) function leads to the induction of the evolutionarily conserved unfolded protein response (UPR), essential for recovering cellular homeostasis, or if recovery is impossible, leading to cell death. Chromatin-associated proteins have widespread effects on gene regulation, which are particularly important in response to stress conditions. We describe a regulatory link between the UPR and heterochromatin protein like-2, the
Caenorhabditis elegans
homolog of heterochromatin protein 1 (HP1). Our work suggests that loss of HP1 promotes the robustness of the ER stress response following a hormetic stress by activating the UPR and autophagy. These findings could have an impact on multiple aspects of disease biology.
Migratory restlessness in captive individuals predicts actual departure in the wild
Authors: Eikenaar Cas , Klinner Thomas , Szostek K. Lesley , Bairlein Franz
Published: April 2014

In captivity, migratory birds show increased activity during the time that they would normally migrate. The phenology and intensity of such ‘migratory restlessness’ has been shown to mirror species- and population-specific migration patterns observed in the wild and has consequently been used as a proxy for the motivation to migrate. Many studies doing so, however, were aiming to explain among-individual variation in migratory behaviour or traits, and not species- or population-specific traits. These studies thus assumed that, also at the level of the individual, migratory restlessness is an accurate proxy for the motivation to migrate. We tested this assumption for the first time and found that it holds; individuals showing very little migratory restlessness remained at stopover for longer than one night, whereas most individuals showing more restlessness departed sooner. This finding validates the use of migratory restlessness as a proxy for the motivation to migrate, thereby justifying the conclusions made in a large body of research on avian migration.
Parasite-mediated selection drives an immunogenetic trade-off in plains zebras (Equus quagga)
Authors: Kamath Pauline L. , Turner Wendy C. , Küsters Martina , Getz Wayne M.
Published: April 2014

Pathogen evasion of the host immune system is a key force driving extreme polymorphism in genes of the major histocompatibility complex (MHC). Although this gene family is well characterized in structure and function, there is still much debate surrounding the mechanisms by which MHC diversity is selectively maintained. Many studies have investigated relationships between MHC variation and specific pathogens, and have found mixed support for and against the hypotheses of heterozygote advantage, frequency-dependent or fluctuating selection. Few, however, have focused on the selective effects of multiple parasite types on host immunogenetic patterns. Here, we examined relationships between variation in the equine MHC gene, ELA-DRA, and both gastrointestinal (GI) and ectoparasitism in plains zebras (Equus quagga). Specific alleles present at opposing population frequencies had antagonistic effects, with rare alleles associated with increased GI parasitism and common alleles with increased tick burdens. These results support a frequency-dependent mechanism, but are also consistent with fluctuating selection. Maladaptive GI parasite ‘susceptibility alleles’ were reduced in frequency, suggesting that these parasites may play a greater selective role at this locus. Heterozygote advantage, in terms of allele mutational divergence, also predicted decreased GI parasite burden in genotypes with a common allele. We conclude that an immunogenetic trade-off affects resistance/susceptibility to parasites in this system. Because GI and ectoparasites do not directly interact within hosts, our results uniquely show that antagonistic parasite interactions can be indirectly modulated through the host immune system. This study highlights the importance of investigating the role of multiple parasites in shaping patterns of host immunogenetic variation.
Proteases involved during oxidative stress-induced poly(ADP-ribose) polymerase-mediated cell death in Dictyostelium discoideum
Authors: Rajawat Jyotika , Alex Tina , Mir Hina , Kadam Ashlesha , Begum Rasheedunnisa
Published: April 2014

Apoptosis involves a cascade of caspase activation leading to the ordered dismantling of critical cell components. However, little is known about the dismantling process in non-apoptotic cell death where caspases are not involved.Dictyostelium discoideumis a good model system to study caspase-independent cell death where experimental accessibility of non-apoptotic cell death is easier and molecular redundancy is reduced compared with other animal models. Poly(ADP-ribose) polymerase (PARP) is one of the key players in cell death. We have previously reported the role of PARP in development and the oxidative stress-induced cell death ofD. discoideum. D. discoideumpossesses nine PARP genes and does not have a caspase gene, and thus it provides a better model system to dissect the role of PARP in caspase-independent cell death. The current study shows that non-apoptotic cell death inD. discoideumoccurs in a programmed fashion where proteases cause mitochondrial membrane potential changes followed by plasma membrane rupture and early loss of plasma membrane integrity. Furthermore, the results suggest that calpains and cathepsin D, which are instrumental in dismantling the cell, act downstream of PARP. Thus, PARP, apoptosis inducing factor, calpains and cathepsin D are the key players inD. discoideumcaspase-independent cell death, acting in a sequential manner.
Building realistic assemblages with a Joint Species Distribution Model
Authors: Harris David J.
Published: April 2014

1. Species distribution models (SDMs) can be used to predict how individual species---and whole assemblages of species---will respond to a changing environment. Until now, these models have either assumed (1) that species' occurrence probabilities are uncorrelated, or (2) that species respond linearly to preselected environmental variables. These two assumptions currently prevent ecologists from modeling assemblages with realistic co-occurrence and species richness properties. 2. This paper introduces a stochastic feedforward neural network, called mistnet, which makes neither assumption. Thus, unlike most SDMs, mistnet can account for non-independent co-occurrence patterns driven by unobserved environmental heterogeneity. And unlike recently proposed Joint SDMs, mistnet can also learn nonlinear functions relating species' occurrence probabilities to environmental predictors. 3. Mistnet makes more accurate predictions about the North American bird communities found along Breeding Bird Survey transects than several alternative methods tested. In particular, typical assemblages held out of sample for validation were nearly 50,000 times more likely under the mistnet model than under independent combinations of single-species models. 4. Apart from improved accuracy, mistnet shows two other important benefits for ecological research and management. First: by analyzing co-occurrence data, mistnet can identify unmeasured---and perhaps unanticipated---environmental variables that drive species turnover. For example, mistnet identified a strong grassland/forest gradient, even though only temperature and precipitation were given as model inputs. Second: mistnet is able to take advantage of incomplete data sets to guide its predictions towards more realistic assemblages. For example, mistnet automatically adjusts its expectations to include more forest-associated species in response to a stray observation of a forest-dwelling warbler.
Principal-teacher high-quality exchange indicators and student achievement: testing a model
Authors: Reza Zeinabadi Hassan
Published: April 2014

Purpose

– Research findings claim that indicators, representing high-quality exchanges between leaders and followers, are important predictors of organizational effectiveness. There is scarce evidence related to the role of these indicators in student achievement. The purpose of this paper is to test a hypothesized model including three important high-quality exchange indicators.

Design/methodology/approach

– Totally, 449 teachers from 166 elementary schools in Tehran provided data on trust in principal and procedural justice and 166 principals provided data on organizational citizenship behavior of teachers. Student achievement was calculated by averaging grade five students’ scores on district examinations in science and math. Data were collected in each school during regularly scheduled meetings and were analyzed using correlation analysis and structural equation modeling.

Findings

– The hypothesized model has an adequate fit to observed data, supporting the argument that principal-teacher high-quality exchanges provide positive outcomes in the form of student achievement.

Originality/value

– Since most studies on high-quality exchange indicators are limited to non-educational settings, this study extends this line of inquiry in public schools. It also contributes to school effectiveness literature by providing empirical evidence concerning the link between trust in principal, procedural justice, organizational citizenship behavior, and student achievement.
Leaders need to develop their willpower
Authors: Karp Tom
Published: April 2014

Purpose

– The purpose of this paper is to investigate the importance of willpower in acts of leadership and, if significant, how a leader should develop his or her willpower in order to take a greater leadership role.

Design/methodology/approach

– The objectives are achieved by a conceptually grounded discussion of the topic, while the arguments are also built upon both a recent survey of leadership acts and on related theoretical material.

Findings

– Willpower governs acts of leadership. Willpower is a capability that has been found to be genetic, but which also is possible to develop by raised awareness, disciplined practice, and extending one's comfort zones by exposing oneself to challenges. Willpower is a mental capability, and if leaders develop their ability to focus their time and energy management, and become more aware of their feelings, they may improve their willpower. Additionally, their energy balance matters: taking care of basics including paying attention to nutrition and to resting, as well as taking up some form of physical/mental practice may have a positive impact on a leader's willpower.

Research limitations/implications

– Research on willpower and its impact on leadership are scarce, and more studies are obviously needed. Since this discussion is conceptual, added empirical research is required.

Practical implications

– Leadership must be exercised in organisations, and willpower is an important vehicle in this respect. The implication for practicing leaders is that they need to develop their willpower. This is a capability that most people can develop by raised awareness and disciplined practice, as well as by exposing themselves to challenging tasks aimed at extending their comfort zones.

Originality/value

– Some argue that willpower is a quality whose exercise suggests positive outcomes in many areas of life. In leadership research, however, willpower is a capacity that is less studied. Conclusions in the paper support the argument that willpower is important for leadership, and that this is a capacity leaders should pay more attention to and develop. The paper is of value to practicing leaders who want to further extend their leadership capabilities.
Teaching the un-teachable: storytelling and meditation in workplace spirituality courses
Authors: Marques Joan , Kumar Dhiman Satinder , Biberman Jerry
Published: April 2014

Purpose

– The purpose of this paper is to review the implementation of two strategies that are actually un-teachable yet highly effective in higher education: meditation and storytelling.

Design/methodology/approach

– Specifically focussing on workplace spirituality as a movement from corporate workers, and consequently, also a teaching topic in management education, the paper first indicates some problems faced in today's world, and relates these to the need for facilitating college courses in more compelling and comprehensive ways.

Findings

– Spirituality and spiritual concepts can involve emotional and other non-cognitive experiences which cannot be taught using traditional teaching approaches such as reading and lecture. Specific approaches, such as meditation and storytelling are useful for teaching spirituality and spiritual concepts in a business school classroom setting. These two strategies provide an opportunity for students to reflect on their experiences and to become more self-aware.

Practical implications

– Using the practical strategies discussed in this paper in management classes turns out to be a positive experience for both the course facilitators and the students.

Originality/value

– Reflecting on the overhaul attempts of management education in universities, even those with the prestige of Harvard and Stanford, the authors discuss some interesting strategies that can help management educators take their course experiences and the results attained to the next level.
Temporal Changes in Survival after Cardiac Surgery Are Associated with the Thirty‐Day Mortality Benchmark
Authors: Maxwell Bryan G. , Wong Jim K. , Miller D. Craig , Lobato Robert L.
Published: April 2014

Objective

To assess the hypothesis that postoperative survival exhibits heterogeneity associated with the timing of quality metrics.

Data Sources

Retrospective observational study using the Nationwide Inpatient Sample from 2005 through 2009.

Study Design

Survival analysis was performed on all admission records with a procedure code for major cardiac surgery (n = 595,089). The day‐by‐day hazard function for all‐cause in‐hospital mortality at 1‐day intervals was analyzed using joinpoint regression (a data‐driven method of testing for changes in hazard).

Data Extraction Methods

A comprehensive analysis of a publicly available national administrative database was performed.

Principal Findings

Statistically significant shifts in the pattern of postoperative mortality occurred at day 6 (95 percent CI = day 5–8) and day 30 (95 percent CI = day 20–35).

Conclusions

While the shift at day 6 plausibly can be attributed to the separation between routine recovery and a complicated postoperative course, the abrupt increase in mortality at day 30 has no clear organic etiology. This analysis raises the possibility that this observed shift may be related to clinician behavior because of the use of 30‐day mortality as a quality metric, but further studies will be required to establish causality.
Remember that patient you saw last week?
Authors: Gildfind Stephen , Egerton‐Warburton Diana , Craig Simon
Published: April 2014

Patient outcome feedback has been defined as ‘the natural process of finding out what happens to one's patients after their evaluation and treatment (in the ED)’. It seems likely that emergency medicine trainees and Fellows will improve their diagnostic accuracy if they increase the frequency with which they find out what happens to their patients. Not only does this allow testing of their own diagnosis with the final diagnosis, but also allows meaningful feedback on therapies commenced in the ED. We believe that seeking outcome feedback should be more actively encouraged by the ACEM training programme.
Roles of Small and Semi‐subsistence Farms in the EU
Authors: Davidova Sophia , Bailey Alastair
Published: April 2014

Small and semi‐subsistence farms (SSFs) in the EU play a number of socio‐economic roles. They maintain rural welfare, keep rural areas populated, contribute to the rural non‐farm economy, and provide environmental public goods such as attractive landscapes. Particularly in the New Member States and in the poorer regions of the Southern EU‐15, one of the most important roles of small and SSFs is supporting social and economic welfare, by acting as a ‘safety net’ for poor families. The disappearance of small and SSFs would often mean increased poverty, losses to the rural non‐farm economy, and depopulation, especially in remote areas, and might result in environmental loss. Variation in the importance of small and SSFs across the rural areas in Europe and the complex reality in which small and SSFs are not the only suppliers of ‘joint products’, explain some of the difficulties of designing EU policy for small and SSFs. What appears to be clear is that small farms and SSFs do produce a range of public goods for which, arguably, compensation is justified, and the case for support on welfare grounds is strong. However, the ability of the Common Agricultural Policy budget and its mechanisms to provide effective compensation for the provision of public goods is a matter of some debate.
CAP Reform Proposals for Small and Semi‐subsistence Farms
Authors: Dwyer Janet
Published: April 2014

Assessing the ‘new’ CAP after 2013 reveals some positive developments encouraging MAs (Managing Authorities) to recognise the particular characteristics of small and SSFs, in designing and implementing appropriate policy options. Because Pillar I aid is unavoidably linked to scale and many small farms cannot or do not claim it, the financial impact of Pillar I on small and SSFs will remain modest. Nevertheless, more options exist for increasing this impact through explicit or implicit tailoring, where Member States so choose. The Small Farmers Scheme, in particular, offers benefits by reducing transaction costs. For Pillar II, the new framework offers more scope for funding tailored to the specific needs of small and SSF farms, but there is no guarantee that this will translate into more cost‐effective Rural Development Programmes, and there is concern that such developments may be disincentivised by other aspects of the approach. Stronger guidance from the European Commission, as well as support from the European Network for Rural Development, could help Managing Authorities to consider the needs of these farms more fully in Rural Development Programme design. In sum, the ‘new’ CAP offers greater potential to support and enhance the value of Europe's small and SSFs than its predecessor. Ultimately, much depends upon choices made at national or regional levels, given the considerable range of options now available.