bluuebunny/crossref_metadata_2025 huggingface dataset:
New Software Framework to Share Research Tools
Authors: Milner Kevin , Becker Thorsten W. , Boschi Lapo , Sain Jared , Schorlemmer Danijel , Waterhouse Hannah
Published: March 2009

Solid Earth Teaching and Research Environment (SEATREE) is a modular and user‐friendly software to facilitate the use of solid Earth research tools in the classroom and for interdisciplinary research collaboration. The software provides a stand‐alone open‐source package that allows users to operate in a “black box” mode, which hides implementation details, while also allowing them to dig deeper into the underlying source code. The overlying user interfaces are written in the Python programming language using a modern, object‐oriented design, including graphical user interactions. SEATREE, which provides an interface to a range of new and existing lower level programs that can be written in any computer programming language, may in the long run contribute to new ways of sharing scientific research. By sharing both data and modeling tools in a consistent framework, published (numerical) experiments can be made truly reproducible again.
Asymmetry of solar activity in cycle 23
Authors: Li K. J. , Chen H. D. , Zhan L. S. , Li Q. X. , Gao P. X. , Mu J. , Shi X. J. , Zhu W. W.
Published: March 2009

Using sunspot groups and sunspot areas from May 1996 to February 2007, we find that solar activity for cycle 23 is dominant in the southern hemisphere, and our results enhance the inferred but uncertain conclusions obtained before. They are as follows: (1) each four cycles, the slope of the fitting straight lines of north‐south asymmetry values changes its sign, and (2) the asymmetry signs of solar activity at both the low (>0° − <10°) and high (≥25° − ≤90°) latitudinal bands are always the same but sometimes differ at the middle latitudinal band (≥10° − <25°). When the former two are the same as the latter, solar activity is asymmetrically distributed in the hemispheres but symmetrically distributed when the former two differ from the latter. Moreover, asymmetry values of solar activity for the whole disk are always located between the first two and the latter and seem to be the averages of the first two and the latter, suggesting that the asymmetry of solar activity may be a function of latitude. In the forthcoming cycle 24, asymmetry of solar activity is inferred as being similar to cycle 12, and solar activity should remain dominant in the southern hemisphere.
Anti‐drug vaccines to treat substance abuse
Authors: Kinsey Berma M , Jackson David C , Orson Frank M
Published: March 2009

Substance abuse is a growing world‐wide problem. The big four drugs of abuse that might lend themselves to immunotherapy are nicotine, cocaine, morphine/heroin and methamphetamine. Tobacco abuse has a well‐known enormous impact on major chronic cardiovascular and pulmonary diseases, while the last three, aside from their neuropsychological effects, are illegal, leading to crime and incarceration as well as the transmission of viral diseases. Having an efficient vaccine that would generate antibodies to sequester the drug and prevent its access to the brain could go a long way toward helping a motivated addict quit the addiction. This review will discuss what has been done to bring such vaccines to human use, and what the challenges are for the future of this promising intervention.
KLF4 positively regulates human ghrelin expression
Authors: Lee Hyo Jung , Kang Young Mi , Moon Chang Suk , Joe Myung Kuk , Lim Joo Hyun , Suh Young Ho , Song Jihyun , Jung Myeong Ho
Published: March 2009

Ghrelin, an endogenous ligand of the GH (growth hormone) secretagogue receptor, influences many metabolic processes including GH secretion, food intake, energy balance, insulin secretion and adipogenesis. Although ghrelin exhibits a variety of biological functions, the mechanism by which ghrelin expression is regulated is unknown. Ghrelin is expressed in the gastrointestinal tract, predominantly in the stomach, as is KLF4 (Krüppel-like factor 4). Therefore we investigated whether ghrelin expression is associated with KLF4, and found that the tissue distribution of ghrelin corresponded with that of KLF4. Furthermore, treatment with butyrate, an inducer of KLF4 expression, stimulated ghrelin expression, and fasting, which induces ghrelin expression, also increased KLF4 expression, suggesting that ghrelin expression is associated with KLF4. Then, we investigated the effects of KLF4 on the human ghrelin-promoter activity and identified a KLF4-responsive region in the promoter. KLF4 expression specifically stimulated human ghrelin-promoter activity in a dose-dependent manner in human gastric-cancer AGS cells. However, this effect was not seen in response to a mutant KLF4 construct. Transfection studies using mutant constructs containing 5′-deletions in the human ghrelin promoter revealed that the KLF4-responsive element is located between −1228 and −1105. Electrophoretic mobility shift assays using oligonucleotides containing −1165/−1146 revealed the binding of KLF4 to the human ghrelin promoter. Finally, deletion of the −1165/−1146 region abrogated KLF4-induced transactivation of the ghrelin promoter. Collectively, these results indicate that KLF4 positively regulates human ghrelin expression via binding to a KLF-responsive region in the promoter.
Cross-Dialectal Perceptual Experiences of Speech-Language Pathologists in Predominantly Caucasian American School Districts
Authors: Robinson Gregory C. , Stockman Ida J.
Published: March 2009

Purpose

This study aimed to determine if the number and type of African American English (AAE) features that are spoken in sentences influence speech-language pathologists' (SLPs') judgments of (a) how noticeable the dialect is (dialect detectability) and (b) how understandable a speaker is to others (comprehensibility).

Method

Certified SLPs with little conversational experience with AAE were recruited from predominantly Caucasian American school districts in Michigan. They listened to sentences that contained varying amounts and types of AAE phonological features. The SLPs rated the sentences on 5-point scales regarding dialect detectability and comprehensibility. The ratings for the different sentences were compared to determine how the variables contributed to the SLPs' judgments of AAE.

Results

Both dialect detectability and comprehensibility ratings were affected by the number of AAE features that were included in the sentences. The types of AAE features consistently affected the comprehensibility ratings but less consistently affected the dialect detectability ratings.

Conclusion

Multiple factors may affect SLPs' perceptions of AAE. The outcomes have both theoretical and practical implications.
A Case for the Sentence in Reading Comprehension
Authors: Scott Cheryl M.
Published: March 2009

Purpose

This article addresses sentence comprehension as a requirement of reading comprehension within the framework of the narrow view of reading that was advocated in the prologue to this forum. The focus is on the comprehension requirements of complex sentences, which are characteristic of school texts.

Method

Topics included in this discussion are (a) evidence linking sentence comprehension and syntax with reading, (b) syntactic properties of sentences that make them difficult to understand, (c) clinical applications for the assessment of sentence comprehension as it relates to reading, and (d) evidence and methods for addressing sentence complexity in treatment.

Conclusion

Sentence complexity can create comprehension problems for struggling readers. The contribution of sentence comprehension to successful reading has been overlooked in models that emphasize domain-general comprehension strategies at the text level. The author calls for the evaluation of sentence comprehension within the context of content domains where complex sentences are found.
Validity of Teacher Report for Assessing the Emergent Literacy Skills of At-Risk Preschoolers
Authors: Cabell Sonia Q. , Justice Laura M. , Zucker Tricia A. , Kilday Carolyn R.
Published: March 2009

Purpose

The purpose of this study was to determine the predictive validity of teacher report for assessing the emergent literacy skills of preschool-age children. The aims were twofold: (a) to examine predictive relationships between teacher report and direct behavioral assessment, and (b) to examine the extent to which teacher report accurately differentiates children who are exhibiting low levels of emergent literacy skills relative to their peers.

Method

Forty-four preschool teachers completed a rating form reporting the print-related emergent literacy skills of 209 children who were enrolled in their classrooms. Approximately 2 months later, the children completed direct assessments of these skills.

Results

Correlations between teacher report and children’s performance on direct behavioral assessments were positive, moderate to large in size, and statistically significant. In terms of classifying children into groupings based on risk (e.g., at risk, low risk), global teacher ratings demonstrated a sensitivity of 51.9% and a specificity of 87.9%.

Clinical Implications

The present results indicate that teacher report provides a somewhat valid representation of children’s skills. However, the diagnostic accuracy of teacher report for identifying children who are at risk is generally low. With this limitation in mind, teacher report can provide an important complement to current assessment approaches that are used in preschool settings.
Looking Through an Adolescent Literacy Lens at the Narrow View of Reading
Authors: Ehren Barbara J.
Published: March 2009

Purpose

This commentary is a personal reaction to A. G. Kamhi’s (2007) article on the “narrow view” of reading and his suggestion that this view be adopted as a way to address the reading problems of children and adolescents.

Method

In this article, I consider the narrow view of reading from an adolescent literacy perspective and discuss the practical implications of adopting this view in the schools. Discussion revolves around the complexities of reading comprehension, comprehension as a teachable set of complex processes, and the speech-language pathologist’s role in reading comprehension.

Conclusion

Although I acknowledge that the narrow view of reading may have merit, I opine that it may create more problems than it solves.
Coppers Context, and Conjoints: A Reassessment of Tam
Authors: Bouwman Harry , van de Wijngaert Lidwien
Published: March 2009

This study examines the role and explanatory value of context-, task- and information-related characteristics vis-a-vis individual characteristics in relation with respect to the adoption of mobile technologies and applications. We combine insights from adoption and acceptance literature with media choice and task-technology fit theories. These insights are applied to a case in which police officers use mobile communication tools and information technologies. Officers were asked which mobile applications they preferred to use in specific situations (contexts) and for specific tasks. In a structural equation model focusing exclusively on individual TAM-related characteristics, such as perceived usefulness and perceived ease of use, as well as on a generic media fit concept, the explanatory value of these concepts turns out to be high. We extend our study, based on Ajzen and Madden (1986) by arguing that, in addition to personal characteristics, contextual characteristics, in combination with task-related characteristics, play an important role in people's preferences for specific technologies. Conjoint analysis focusing on contextual and task-related characteristics yields relevant insights. When context-related and individual characteristics are combined into a single hierarchical linear model, the significance of the concepts used in TAM turns out to be low, while context-related issues stand out. On the basis of our research, we conclude that TAM models are too generic to fully explain people's intention to use mobile technologies. Future research should aim at developing models that take contextual and task-related factors into account when studying mobile applications.
Magnetic properties of Fe-based ribbons with controlled permeability prepared by continuous pulse annealing under tensile stress
Authors: Takagi Kotaro , Yanai Takeshi , Takahashi Ken-ichiro , Nakano Masaki , Fukunaga Hirotoshi , Yoshizawa Yoshihito
Published: March 2009

An amorphous Fe73.5Cu1Nb3Si15.5B7 ribbon was pulse annealed continuously under tensile stress by being passed through in an infrared furnace switched on and off repeatedly for preparation of a nanocrystallized toroidal core with controlled permeability. Optimization of the duty ratio D(=Ton/T) of the furnace enabled us to obtain ribbons with low Hc(<10 A/m) and completely developed anisotropy under a high moving velocity of the ribbon, 50 cm/min. ac magnetic properties of a toroidal core, which is made from the pulse-annealed ribbon, at Bm=0.1 T were measured in the frequency range of 0.1–1 MHz. The loss of the prepared core at f=0.1 MHz is 0.50 J/m3, which is lower than those for a gapped ferrite, sendust powder, and amorphous powder core. The relative permeability of approximately 330 was constant up to 1 MHz. These results suggest that the continuous stress annealing by pulse annealing method is one of the hopeful methods for preparation of a long ribbon with excellent magnetic properties.
Antiferromagnetic order in (Lu0.8Ce0.2)2Fe17 and Lu2Fe16.5Ru0.5: High pressure study
Authors: Tereshina E. A. , Andreev A. V. , Kamarád J. , Isnard O.
Published: March 2009

The antiferromagnetic state observed in Lu2Fe17 at elevated temperatures is stabilized down to the ground state in (Lu0.8Ce0.2)2Fe17 and Lu2Fe16.5Ru0.5. The Néel temperature TN decreases from 274 K in Lu2Fe17 to 247 and 208 K in (Lu0.8Ce0.2)2Fe17 and Lu2Fe16.5Ru0.5, respectively. Both compounds exhibit the easy-plane type of magnetic anisotropy and a metamagnetic transition at fields below 1 T. External pressure pushes the transition toward a higher field and reduces the magnetization as well as TN to 234 and 185 K for (Lu0.8Ce0.2)2Fe17 and Lu2Fe16.5Ru0.5, respectively, under pressure 0.8 GPa. The pressure and the substitution effects can be understood in terms of exchange interaction varying strongly with changes in the lattice parameter c for (Lu0.8Ce0.2)2Fe17, while for Lu2Fe16.5Ru0.5, the change in magnetic structure occurs due to the weakening of the positive exchange interaction as a result of the reduction in the Fe magnetic moments at 12 k sites.
Nanocrystalline Y0.5Sm0.5Co5 ribbons obtained by melt spinning
Authors: Hidalgo-González J. L. , Gómez F. J. Rivera , Matutes-Aquino J. A.
Published: March 2009

Nanocrystalline Y0.5Sm0.5Co5 ribbons were obtained by melt spinning using a copper wheel surface speed of 40 m/s. X-ray diffraction patterns from the as-cast ground alloy and from the melt-spun ribbons were indexed as CaCu5-like hexagonal structure. Crystallographic texture was observed and a dendritic microstructure with a dendrite size between 1 and 5 μm from the noncontacting ribbon surface was measured. In addition, a finer microstructure on the contacting surface was observed. Magnetic measurements, corrected for the demagnetizing field, show a nonsaturated magnetization curve. An initial magnetization curve typical of a nucleation-type magnetization mechanism was observed and an intrinsic coercivity of 1.2 T and a Mr/Ms ratio equal to 0.67 were measured.
Methods of torque ripple reduction for flux reversal motor
Authors: Vakil Gaurang , Sheth N. K. , Miller David
Published: March 2009

This paper presents two-dimensional finite element based results for various methods of torque ripple reduction in flux-reversal motors. The effects of variation in magnet and rotor pole heights, rotor pole skewing, and multiple teeth per rotor pole on the cogging torque, developed torque, torque ripple, and phase inductance and also an optimum value of the magnet and rotor pole heights, skew angle, and choice of teeth per rotor pole with the teeth depth resulting in torque ripple reduction are presented.
Deducing local extremely low frequency field values from large sense coil fluxmeter measurements
Authors: Adly A. A. , Abdel-Aziz M. M. , Hosny N. S.
Published: March 2009

Great interest has been increasing in the precise measurements of extremely low frequency ambient magnetic fields which have been recently involved in numerous biological, noise, and compatibility problems. While fluxmeters equipped with sense coils are classified among the most convenient and cheap devices used in measuring such fields, they can never resolve spatially changing field distributions within their sense coil dimensions. This paper presents an approach, based on deconvoluting the sense coil response from spatial measurements, which can be used to infer local field distributions within the fluxmeter sense coil dimensions. Theoretical details as well as sample measurements and simulation results are given in the paper.
Electronic and optical properties of pure and Ce3+-doped MgS single crystals: A first-principles prediction
Authors: Chen Z. J. , Zu X. T. , Wang Y. X. , Xue S. W.
Published: March 2009

The electronic and optical properties for pure and Ce3+-doped MgS crystals have been investigated by using the first-principles total energy calculations. The results show that MgS:Ce has a direct band gap of 2.38 eV, and the top of the valence band is determined by S 3p and Ce 4f states and the bottom of the conduction band is determined by Mg 2p, 3s and Ce 4f, 5d states, respectively. The Ce–S bond shows more ionic character than the Mg–S bond. Our results suggest that the green emission from MgS:Ce is produced by doped cerium. Furthermore, it is shown that MgS:Ce is a promising dielectric material.
Scaling identities for solitons beyond Derrick’s theorem
Authors: Manton Nicholas S.
Published: March 2009

New integral identities satisfied by topological solitons in a range of classical field theories are presented. They are derived by considering independent length rescalings in orthogonal directions, or equivalently, from the conservation of the stress tensor. These identities are refinements of Derrick’s theorem.
A simple three-dimensional vortex micromixer
Authors: Long Maureen , Sprague Michael A. , Grimes Anthony A. , Rich Brent D. , Khine Michelle
Published: March 2009

We demonstrate rapid homogenous micromixing at low Reynolds numbers in an easily fabricated and geometrically simple three-dimensional polystyrene vortex micromixer. Micromixing is critically important for miniaturized analysis systems. However, rapid and effective mixing at these small scales remains a persistent challenge. We compare our micromixer’s performance against a two-dimensional square-wave design by examining its effectiveness in mixing solutions of dissimilar concentration as well as suspension solutions comprised of microparticles. Numerical simulations confirm our experimental observations and provide insights on the self-rotational mixing dynamics achieved with our simple geometry at low Reynolds numbers. This rapid, robust, and easily fabricated micromixer is amenable readily to large scale integration.
Is the p-chloroaniline anion bound almost entirely by correlation?
Authors: Smuczyńska Sylwia , Gwarda Iwona , Anusiewicz Iwona , Skurski Piotr
Published: March 2009

Negatively charged p-chloroaniline (PCA) was studied using ab initio coupled-cluster CCSD(T) method with the aug-cc-pVDZ+5s4p3d basis sets. It was found that the PCA forms a stable (although weakly bound) anionic state whose electron binding energy is 81 cm−1. The analysis of various contributions to electronic stability of the PCA anion showed the enormously large terms resulting from the electron correlation effects. It was concluded that the negatively charged PCA is an anion bound almost entirely by electron correlation because these effects are responsible for 96% of the total electron binding energy of PCA−.
Multiwalled carbon nanotube films as small-sized temperature sensors
Authors: Di Bartolomeo A. , Sarno M. , Giubileo F. , Altavilla C. , Iemmo L. , Piano S. , Bobba F. , Longobardi M. , Scarfato A. , Sannino D. , Cucolo A. M. , Ciambelli P.
Published: March 2009

We present the fabrication of thick and dense carbon nanotube networks in the form of freestanding films (CNTFs) and the study of their electric resistance as a function of the temperature, from 4 to 420 K. A nonmetallic behavior with a monotonic R(T) and a temperature coefficient of resistance around −7×10−4 K−1 is generally observed. A behavioral accordance of the CNTF conductance with the temperature measured by a solid-state thermistor (ZnNO, Si, or Pt) is demonstrated, suggesting the possibility of using CNTFs as temperature small-sized (freely scalable) sensors, besides being confirmed by a wide range of sensitivity, fast response, and good stability and durability. Concerning electric behavior, we also underline that a transition from nonmetal to metal slightly below 273 K has been rarely observed. A model involving regions of highly anisotropic metallic conduction separated by tunneling barrier regions can explain the nonmetallic to metallic crossover based on the competing mechanisms of the metallic resistance rise and the barrier resistance lowering.
Second-order susceptibilities of ZnO nanorods from forward second-harmonic scattering
Authors: Geren K. , Liu S. W. , Zhou H. J. , Zhang Y. , Tian R. , Xiao Min
Published: March 2009

A forward second-harmonic scattering method for determining the second-order susceptibility coefficients of ZnO nanorods on the order of 100 nm in diameter is presented. The long coherence length and strong intensity of the forward second-harmonic signal allow for a simple theoretical model to match the experimental measurements; this results in getting accurate values for the second-order susceptibility tensors. Different signs of d31 and d33 are confirmed. The results also show that Kleinman’s symmetry is destroyed at a near-resonant second-harmonic wavelength of 405 nm for the ZnO nanorods.
Hydrodynamic diffusion and mass transfer across a sheared suspension of neutrally buoyant spheres
Authors: Wang Luying , Koch Donald L. , Yin Xiaolong , Cohen Claude
Published: March 2009

We present experimental, theoretical, and numerical simulation studies of the transport of fluid-phase tracer molecules from one wall to the opposite wall bounding a sheared suspension of neutrally buoyant solid particles. The experiments use a standard electrochemical method in which the mass transfer rate is determined from the current resulting from a dilute concentration of ions undergoing redox reactions at the walls in a solution of excess nonreacting ions that screen the electric field in the suspension. The simulations use a lattice-Boltzmann method to determine the fluid velocity and solid particle motion and a Brownian tracer algorithm to determine the chemical tracer mass transfer. The mass transport across the bulk of the suspension is driven by hydrodynamic diffusion, an apparent diffusive motion of tracers caused by the chaotic fluid velocity disturbances induced by suspended particles. As a result the dimensionless rate of mass transfer (or Sherwood number) is a nearly linear function of the dimensionless shear rate (Peclet number) at moderate values of the Peclet number. At higher Peclet numbers, the Sherwood number grows more slowly due to the mass transport resistance caused by a molecular-diffusion boundary layer near the solid walls. Fluid inertia enhances the rate of mass transfer in suspensions with particle Reynolds numbers in the range of 0.5–7.
Capillary oscillations of a constrained liquid drop
Authors: Bostwick J. B. , Steen P. H.
Published: March 2009

An inviscid spherical liquid drop held by surface tension exhibits linear oscillations of a characteristic frequency and mode shape (Rayleigh oscillations). If the drop is pinned on a circle of contact the mode shapes change and the frequencies are shifted. The linear problem of inviscid, axisymmetric, volume-preserving oscillations of a liquid drop constrained by pinning along a latitude is solved here. The formulation gives rise to an integrodifferential boundary value problem, similar to that for Rayleigh oscillations, and for oscillations of a drop in contact with a spherical bowl [M. Strani and F. Sabetta, J. Fluid Mech. 141, 233 (1984)], only more constrained. A spectral method delivers a truncated solution to the eigenvalue problem. A numerical routine has been used to generate the eigenfrequencies/eigenmodes as a function of the location of the pinned circle of constraint. The effect of pinning the drop is to introduce a new low-frequency eigenmode. The center-of-mass motion, important in application, is partitioned among all the eigenmodes but the low-frequency mode is its principal carrier.
Measurements of spatial line emission profiles in the main scrape-off layer of the DIII-D tokamak
Authors: Groth M. , Ellis R. M. , Brooks N. H. , Fenstermacher M. E. , Lasnier C. J. , Meyer W. H. , Moeller J. M.
Published: March 2009

A video camera system is described as that measures the spatial distribution of visible line emission emitted from the main scrape-off layer (SOL) of plasmas in the DIII-D tokamak. A wide-angle lens installed on an equatorial port and an in-vessel mirror, which intercepts part of the lens’ view, provide simultaneous tangential views of the SOL on the low-field and high-field sides of the plasma’s equatorial plane. Tomographic reconstruction techniques are used to calculate the two-dimensional (2D) poloidal profiles from the raw data, and one-dimensional (1D) poloidal profiles simulating chordal views of other optical diagnostics from the 2D profiles. The 2D profiles can be compared with SOL plasma simulations; the 1D profiles with measurements from spectroscopic diagnostics. Sample results are presented, which elucidate carbon transport in plasmas with toroidally uniform injection of methane and argon transport in disruption mitigation experiments with massive gas jet injection.
Fast and durable electromechanical shutter for imaging spectrometers
Authors: Pöhler Denis
Published: March 2009

The presented electromechanical shutter for imaging spectrometers meets the needs of imaging spectroscopy with continuous exposure at short integration times. The shutter blocks the light during readout of the two-dimensional charge-coupled device detector to preserve the spatial resolution. Commercially available shutters have significant problems in terms of lifetime and sometimes also in speed. The developed shutter is fast with a total response time of 3 ms to open and 5 ms to close and durable since the lifetime exceeds 20×106 exposures. The shutter is constructed with only a few simple mechanical parts. It can therefore easily be repaired, which reduces the running cost. The construction of the shutter, the mechanical properties, and the required optical configurations will be described. Furthermore the performance for imaging spectroscopic measurements with short exposure times is demonstrated.
Origin of the enthalpy features of water in 1.8 nm pores of MCM-41 and the large Cp increase at 210 K
Authors: Johari G. P.
Published: March 2009

It is shown that exothermic and endothermic features of dHm/dt observed on heating rapidly precooled and slowly precooled states of water in 1.8 nm pores of MCM-41 and the unusually large increase in the specific heat in the 210–230 K range [M. Oguni, Y. Kanke, S. Namba, and AIP Conf, Proc. 982, 34 (2008)] are inconsistent with kinetic unfreezing of a disordered solid, or glass softening. The exotherm is attributable to the melt’s gradual conversion to distorted icelike structures and the endotherm to the reverse process until their fractional amounts reach a reversible equilibrium on heating. The large increase in Cp,m with T is attributed to the latent heat, similar to that seen on premelting of fine grain crystals. The available calorimetric data on freezing and melting and the pore-size dependence of the features support this interpretation. The findings also put into question a conclusion from neutron scattering studies that in 1.8 nm pores water undergoes a structural and kinetic transition at ∼225 K while remaining a liquid.
Polyamorphism in tin tetraiodide
Authors: Fuchizaki Kazuhiro , Hase Takaki , Yamada Akihiro , Hamaya Nozomu , Katayama Yoshinori , Funakoshi Ken-ichi
Published: March 2009

The discovery of a first-order phase transition in fluid phosphorus aroused renewed interest in polyamorphism in liquids with a locally tetrahedral molecular structure. We have performed in situ synchrotron x-ray diffraction measurements on tin tetraiodide, which consists of SnI4 tetrahedral molecules at ambient pressure, and established that the liquid forms existing above and below 1.5 GPa, where the slope of the melting curve of the solid phase changes abruptly, have different structures. This discovery offers evidence of thermodynamically stable polyamorphism in general compounds as well as in elements. A possible phase diagram that includes the two amorphous states already found is proposed based on the pseudobinary regular solution model. The vertex-to-face orientation between the nearest molecules plays a key role in the transition from the low-pressure to the high-pressure liquid phase.
Second-harmonic generation and spectrum modulation by an active nonlinear metamaterial
Authors: Wang Zhiyu , Luo Yu , Peng Liang , Huangfu Jiangtao , Jiang Tao , Wang Dongxing , Chen Hongsheng , Ran Lixin
Published: March 2009

The nonlinear properties of a metamaterial sample composed of double-layer metallic patterns and voltage controllable diodes are experimentally investigated. Second harmonics and spectrum modulations are clearly observed in a wide band of microwave frequencies, showing that this kind of metamaterial is not only tunable by low dc bias voltage but also behaves strong nonlinear property under a small power incidence. These properties are difficult to be found in normal naturally occurring materials.
A nonbiological system offers insight into biological synchronization
Authors: Miller Johanna
Published: March 2009

Porous microparticles suspended in a reagent solution can make the transition to synchronous activity in two ways—one gradual, the other sudden.
John Wheeler’s work on particles, nuclei, and weapons
Authors: Ford Kenneth W.
Published: March 2009

For a time, Wheeler regarded nuclear physics as the best way to “do battle with nature.” But then he became attracted to the simplicity of the muon, which is immune to the strong nuclear force. He himself, however, could not escape the ramifications of that force in a world at war.
The superhydrophilic and superoleophilic leaf surface of Ruellia devosiana (Acanthaceae): a biological model for spreading of water and oil on surfaces
Authors: Koch Kerstin , Blecher Inga Christina , König Gabriele , Kehraus Stefan , Barthlott Wilhelm
Published: March 2009

Most leaves of plants are hydrophobic or even superhydrophobic. Surprisingly the leaves of the tropical herb of Ruellia devosiana Makoy ex E. Morr. Hort. (Acanthaceae) are superamphiphilic. Water droplets (10 µL) spread to a film with a contact angle of zero degree within less than 0.3 s. Such surfaces with a high affinity to water are termed superhydrophilic. Droplets of oil applied on R. devosiana leaves and replicas showed a similar spreading behaviour as water. These surfaces are superoleophilic, and in combination with their superhydrophilicity they are called superamphiphilic. Independent of the growing conditions, a reversibility of the superhydrophilicity in R. devosiana leaves was found. Additionally, on 90° tilted leaves a pressure free capillary transport of water occurs against the force of gravity. By using a low pressure environmental scanning electron microscope (ESEM), the water condensation and evaporation process on the leaves has been observed. The leaf surfaces are composed of five different cell types: conical cells, glands, multicellular hairs, hair-papilla cells and longitudinal expanded, flat epidermis cells, which, in combination with the surrounding papilla cells, form channel like structures. Replication of the leaf surface structure and coating of the replicas with hydrophilic Tween 20 and a water soluble extract gained from the leaf surfaces resulted in artificial surfaces with the same fast water spreading properties as described for the leaves.
Phylogeny and generic concepts of the parasitoid wasp family Aulacidae (Hymenoptera: Evanioidea)
Authors: Turrisi Giuseppe F. , Jennings John T. , Vilhelmsen Lars
Published: March 2009

The results of the first phylogenetic investigation of members of the Aulacidae of the world are presented. The main objective was to test the monophyly of the currently recognised genera. In total, 79 morphological characters were scored for a substantial sample of the extant aulacid fauna, including 72 species, as well as 12 outgroup taxa belonging to Evaniidae, Gasteruptiidae, Megalyridae, Trigonalidae, Braconidae and Stephanidae. All zoogeographic regions were represented. The dataset was analysed under different conditions (ordered, unordered, equal and implied weighting). The results under different weighting conditions are not fully congruent and many relationships remain unresolved. However, the analyses demonstrate that the current generic classification of the Aulacidae is not a natural one. There is support for a very large, monophyletic clade which includes all Pristaulacus Kieffer spp. + Panaulix Benoit spp. This suggests a wider generic concept for Pristaulacus, which is redefined and rediagnosed here. As a consequence, Panaulix becomes a junior synonym of Pristaulacus (syn. nov.), and the two described species of Panaulix are transferred to Pristaulacus: Pristaulacus rex (Benoit, 1984), comb. nov., and Pristaulacus irenae (Madl, 1990), comb. nov. The genus Aulacus Jurine was consistently paraphyletic and is not valid as currently defined. Furthermore, we failed to retrieve a consistent topology among the different clades of Aulacus. A satisfactory reclassification of Aulacus, however, requires a much more comprehensive taxon sample and/or additional character data.
Soil indicators and their use by farmers in the Billabong Catchment, southern New South Wales
Authors: Kelly B. , Allan C. , Wilson B. P.
Published: March 2009

‘Soil health’ programs and projects in Australia’s agricultural districts are designed to influence farmers’ management behaviours, usually to produce better outcomes for production, conservation, and sustainability. These programs usually examine soil management practices from a soil science perspective, but how soils are understood by farmers, and how that understanding informs their farm management decisions, is poorly documented. The research presented in this paper sought to better understand how dryland farmers in the Billabong catchment of southern New South Wales use soil indicators to inform their management decisions. Thematic content analysis of transcripts of semi-structured, face-to-face interviews with farmers suggest several themes that have implications for soil scientists and other professionals wishing to promote soil health in the dryland farming regions of south-eastern Australia. In particular, all soil indicators, including those related to soil ‘health’, need to relate to some clear, practical use to farmers if they are to be used in farm decision making. This research highlights a reliance of the participants of this research on agronomists. Reliance on agronomists for soil management decisions may result in increasing loss of connectivity between farmers and their land. If this reflects a wider trend, soil health projects may need to consider where best to direct their capacity-building activities, and/or how to re-empower individual farmers.
Heavy metal distribution, bioaccessibility, and phytoavailability in long-term contaminated soils from Lake Macquarie, Australia
Authors: Kim Kwon-Rae , Owens Gary , Naidu Ravi
Published: March 2009

This study was conducted to investigate the distribution, bioaccessibility, and phytoavailability of heavy metal(loids) in long-term contaminated soils within the vicinity of a lead (Pb) and zinc (Zn) smelter in Lake Macquarie, NSW, Australia. Thirty-two representative surface (0–100 mm) soils were collected from the region surrounding the smelter. The soils were analysed for aqua regia extractable heavy metals (Cu, Zn, Cd, Pb), bioaccessibility using a simplified physiological-based extraction technique (SBET), and phytoavailability using 1 m NH4NO3 extractions, together with key soil properties known to influence metal speciation and availability.
The area was found to be potentially contaminated with heavy metals (Cu, Zn, Cd, Pb) with many soil samples exceeding the Australian Health Investigation Levels for ‘Standard’ residential areas. Lead bioaccessibility ranged from 32 to 100% of the total Pb concentration, with bioaccessibility increasing as metal loading increased. Heavy metal phytoavailability was strongly related to soil pH for Cu (r2 = 0.84, P < 0.001), Pb (r2 = 0.70, P < 0.001), and Cd (r2 = 0.66, P < 0.001), implying that the phytoavailability of these heavy metal was mainly governed by soil acidity. Most significantly, the presence of multiple metals was found to influence metal phytoavailability. For example, the presence of Pb significantly influenced the phytoavailability of Cd (r2 = 0.89, P < 0.001) and Zn (r2 = 0.78, P < 0.001) in mixed heavy metal contaminated soils.
Statistical patterns of carbonates and total organic carbon on soils of Tuber rufum and T. melanosporum (black truffle) brûlés
Authors: García-Montero L. G. , Valverde-Asenjo I. , Díaz P. , Pascual C.
Published: March 2009

The ascocarps of several truffle species, such as Tuber rufum, are harvested in T. melanosporum brûlés; these species reduce T. melanosporum production. Some authors argue that this competition might be due to the evolution of organic matter in the soil. However, soil conditions in brûlés have yet to be clarified, and most studies on T. melanosporum fail to supply statistical data. We propose a study of 40 soils to compare the values for total organic carbon (TOC), pH, and carbonates inside the brûlés with the values for the outer edges of the same brûlés, where T. rufum ascocarps are collected. A principal component analysis relates the soils from the inner brûlés with high active carbonate content and soils outside the brûlés with high TOC and total carbonate content. ANOVA analyses indicate that the mean concentration of active carbonate, total CO32–, and % active/total carbonate differ significantly depending on soil location, but there are no significant differences for pH and TOC. These results lead us to propose a new hypothesis: T. melanosporum mycelia may solubilise active carbonate (<50 μm) and the other carbonate fractions (>50 μm) inside the brûlés; however the environmental conditions of the brûlés could favour a secondary carbonate precipitation with a net increase in active carbonate. This increase would counterbalance carbonate losses from leaching, which would in turn favour T. melanosporum mycelia, suggesting a feedback process.
PD-1 expression by macrophages plays a pathologic role in altering microbial clearance and the innate inflammatory response to sepsis
Authors: Huang Xin , Venet Fabienne , Wang Yvonne L. , Lepape Alain , Yuan Zhenglong , Chen Yaping , Swan Ryan , Kherouf Hakim , Monneret Guillaume , Chung Chun-Shiang , Ayala Alfred
Published: March 2009

Sepsis, a leading cause of death worldwide, involves concomitant expression of an overzealous inflammatory response and inefficient bacterial clearance. Macrophage function is pivotal to the development of these two aspects during sepsis; however, the mechanisms underlying these changes remain unclear. Here we report that the PD-1:PD-L pathway appears to be a determining factor of the outcome of sepsis, regulating the delicate balance between effectiveness and damage by the antimicrobial immune response. To this end we observed that PD-1
−/−
mice were markedly protected from the lethality of sepsis, accompanied by a decreased bacterial burden and suppressed inflammatory cytokine response. To the extent that this is a macrophage-specific aspect of the effects of PD-1, we found the following: first, peritoneal macrophages expressed significantly higher levels of PD-1 during sepsis, which was associated with their development of cellular dysfunction; second, when peritoneal macrophages were depleted (using clodronate liposomes) from PD-1
−/−
mice, the animals' bactericidal capacity was lowered, their inflammatory cytokine levels were elevated, and protection from septic lethality was diminished; and third, blood monocytes from both septic mice and patients with septic shock shared markedly increased PD-1 levels. Together, these data suggest that PD-1 may not only be a dysfunctional marker/effector of macrophages/monocytes, but may also be a potential therapeutic target for designing measures to modulate the innate immune response, thereby preventing the detrimental effects of sepsis.
Molecular basis for changes in behavioral state in ant social behaviors
Authors: Lucas Christophe , Sokolowski Marla B.
Published: March 2009

A hallmark of behavior is that animals respond to environmental change by switching from one behavioral state to another. However, information on the molecular underpinnings of these behavioral shifts and how they are mediated by the environment is lacking. The ant
Pheidole pallidula
with its morphologically and behaviorally distinct major and minor workers is an ideal system to investigate behavioral shifts. The physically larger majors are predisposed to defend the ant nest, whereas the smaller minors are the foragers. Despite this predisposition, majors are able to shift to foraging according to the needs of the colony. We show that the ant foraging (
ppfor
) gene, which encodes a cGMP-dependent protein kinase (PKG), mediates this shift. Majors have higher brain PKG activities than minors, and the spatial distribution of the PPFOR protein differs in these workers. Specifically, majors express the PPFOR protein in 5 cells in the anterior face of the ant brain, whereas minors do not. Environmental manipulations show that PKG is lower in the presence of a foraging stimulus and higher when defense is required. Finally, pharmacological activation of PKG increases defense and reduces foraging behavior. Thus, PKG signaling plays a critical role in
P. pallidula
behavioral shifts.
Caveolae are required for protease-selective signaling by protease-activated receptor–1
Authors: Russo Angela , Soh Unice J. K. , Paing May M. , Arora Puneeta , Trejo JoAnn
Published: March 2009

Protease-activated receptor-1 (PAR
1
) is a G-protein–coupled receptor uniquely activated by proteolysis. Thrombin, a coagulant protease, induces inflammatory responses and endothelial barrier permeability through the activation of PAR
1
. Activated protein C (APC), an anti-coagulant protease, also activates PAR
1
. However, unlike thrombin, APC elicits anti-inflammatory responses and protects against endothelial barrier dysfunction induced by thrombin. We found that thrombin and APC signaling were lost in PAR
1
-deficient endothelial cells, indicating that PAR
1
is the major effector of protease signaling. To delineate the mechanism responsible for protease-selective signaling by PAR
1
, we examined the effect of APC and thrombin on the activation of RhoA and Rac1, small GTPases that differentially regulate endothelial barrier permeability. Thrombin caused robust RhoA signaling but not Rac1 activation, whereas APC stimulated a marked increase in Rac1 activation but not RhoA signaling, consistent with the opposing functions of these proteases on endothelial barrier integrity. Strikingly, APC signaling and endothelial barrier protection effects were abolished in cells lacking caveolin-1, whereas thrombin signaling remained intact. These findings suggest that compartmentalization of PAR
1
in caveolae is critical for APC selective signaling to Rac1 activation and endothelial barrier protection. We further report that APC induces PAR
1
phosphorylation and desensitizes endothelial cells to thrombin signaling but promotes limited receptor cleavage and negligible internalization and degradation even after prolonged APC exposure. Thus, APC selective signaling and endothelial barrier protective effects are mediated through compartmentalization of PAR
1
in caveolae and a novel mechanism of PAR
1
signal regulation.
Imaging the quantal substructure of single IP
3
R channel activity during Ca
2+
puffs in intact mammalian cells
Authors: Smith Ian F. , Parker Ian
Published: March 2009

The spatiotemporal patterning of Ca
2+
signals regulates numerous cellular functions, and is determined by the functional properties and spatial clustering of inositol trisphosphate receptor (IP
3
R) Ca
2+
release channels in the endoplasmic reticulum membrane. However, studies at the single-channel level have been hampered because IP
3
Rs are inaccessible to patch-clamp recording in intact cells, and because excised organelle and bilayer reconstitution systems disrupt the Ca
2+
-induced Ca
2+
release (CICR) process that mediates channel-channel coordination. We introduce here the use of total internal reflection fluorescence microscopy to image single-channel Ca
2+
flux through individual and clustered IP
3
Rs in intact mammalian cells. This enables a quantal dissection of the local calcium puffs that constitute building blocks of cellular Ca
2+
signals, revealing stochastic recruitment of, on average, approximately 6 active IP
3
Rs clustered within <500 nm. Channel openings are rapidly (≈10 ms) recruited by opening of an initial trigger channel, and a similarly rapid inhibitory process terminates puffs despite local [Ca
2+
] elevation that would otherwise sustain Ca
2+
-induced Ca
2+
release indefinitely. Minimally invasive, nano-scale Ca
2+
imaging provides a powerful tool for the functional study of intracellular Ca
2+
release channels while maintaining the native architecture and dynamic interactions essential for discrete and selective cell signaling.
Dynamic remodeling of in-group bias during the 2008 presidential election
Authors: Rand David G. , Pfeiffer Thomas , Dreber Anna , Sheketoff Rachel W. , Wernerfelt Nils C. , Benkler Yochai
Published: March 2009

People often favor members of their own group, while discriminating against members of other groups. Such in-group favoritism has been shown to play an important role in human cooperation. However, in the face of changing conflicts and shifting alliances, it is essential for group identities to be flexible. Using the dictator game from behavioral economics, we demonstrate the remodeling of group identities among supporters of Democratic presidential candidates Barack Obama and Hillary Clinton. After Clinton's concession in June 2008, Democrats were more generous toward supporters of their own preferred candidate than to supporters of the other Democratic candidate. The bias observed in June persisted into August, and disappeared only in early September after the Democratic National Convention. We also observe a strong gender effect, with bias both appearing and subsiding among men only. This experimental study illustrates a dynamic change in bias, tracking the realignment of real world conflict lines and public efforts to reconstitute group identity. The change in salient group identity we describe here likely contributed to the victory of Barack Obama in the 2008 presidential election.