bluuebunny/crossref_metadata_2025 huggingface dataset:
Prefrontal cortical microcircuits bind perception to executive control
Authors: Opris Ioan , Santos Lucas , Gerhardt Greg A. , Song Dong , Berger Theodore W. , Hampson Robert E. , Deadwyler Sam A.
Published: July 2013

During the perception-to-action cycle, our cerebral cortex mediates the interactions between the environment and the perceptual-executive systems of the brain. At the top of the executive hierarchy, prefrontal cortical microcircuits are assumed to bind perceptual and executive control information to guide goal-driven behavior. Here, we tested this hypothesis by comparing simultaneously recorded neuron firing in prefrontal cortical layers and the caudate-putamen of rhesus monkeys, trained in a spatial-versus-object, rule-based match-to-sample task. We found that during the perception and executive selection phases, cell firing in the localized prefrontal layers and caudate-putamen region exhibited similar location preferences on spatial-trials, but less on object- trials. Then, we facilitated the perceptual-executive circuit by stimulating the prefrontal infra-granular-layers with patterns previously derived from supra-granular-layers and produced stimulation-induced spatial preference in percent correct performance on spatial trials, similar to neural tuning. These results show that inter-laminar prefrontal microcircuits play causal roles to the perception-to-action cycle.
IF1, a natural inhibitor of mitochondrial ATP synthase, is not essential for the normal growth and breeding of mice
Authors: Nakamura Junji , Fujikawa Makoto , Yoshida Masasuke
Published: July 2013

IF1 is an endogenous inhibitor protein of mitochondrial ATP synthase. It is evolutionarily conserved throughout all eukaryotes and it has been proposed to play crucial roles in prevention of the wasteful reverse reaction of ATP synthase, in the metabolic shift from oxidative phosphorylation to glycolysis, in the suppression of ROS (reactive oxygen species) generation, in mitochondria morphology and in haem biosynthesis in mitochondria, which leads to anaemia. Here, we report the phenotype of a mouse strain in which IF1 gene was destroyed. Unexpectedly, individuals of this IF1-KO (knockout) mouse strain grew and bred without defect. The general behaviours, blood test results and responses to starvation of the IF1-KO mice were apparently normal. There were no abnormalities in the tissue anatomy or the autophagy. Mitochondria of the IF1-KO mice were normal in morphology, in the content of ATP synthase molecules and in ATP synthesis activity. Thus, IF1 is not an essential protein for mice despite its ubiquitous presence in eukaryotes.
Stability of Measures From Children's Interviews: The Effects of Time, Sample Length, and Topic
Authors: Heilmann John , DeBrock Lindsay , Riley-Tillman T. Chris
Published: July 2013

Purpose

The purpose of this study was to examine the reliability of, and sources of variability in, language measures from interviews collected from young school-age children.

Method

Two 10-min interviews were collected from 20 at-risk kindergarten children by an examiner using a standardized set of questions. Test–retest reliability coefficients were calculated for 8 language measures. Generalizability theory (G-theory) analyses were completed to document the variability introduced into the measures from the child, session, sample length, and topic.

Results

Significant and strong reliability correlation coefficients were observed for most of the language sample measures. The G-theory analyses revealed that most of the variance in the language measures was attributed to the child. Session, sample length, and topic accounted for negligible amounts of variance in most of the language measures.

Conclusion

Measures from interviews were reliable across sessions, and the sample length and topic did not have a substantial impact on the reliability of the language measures. Implications regarding the clinical feasibility of language sample analysis for assessment and progress monitoring are discussed.
Speech Sound Disorders in a Community Study of Preschool Children
Authors: McLeod Sharynne , Harrison Linda J. , McAllister Lindy , McCormack Jane
Published: July 2013

Purpose

To undertake a community (nonclinical) study to describe the speech of preschool children who had been identified by parents/teachers as having difficulties “talking and making speech sounds” and compare the speech characteristics of those who had and had not accessed the services of a speech-language pathologist (SLP).

Method

Stage 1: Parent/teacher concern regarding the speech skills of 1,097 4- to 5-year-old children attending early childhood centers was documented. Stage 2a: One hundred forty-three children who had been identified with concerns were assessed. Stage 2b: Parents returned questionnaires about service access for 109 children.

Results

The majority of the 143 children (86.7%) achieved a standard score below the normal range for the percentage of consonants correct (PCC) on the Diagnostic Evaluation of Articulation and Phonology (Dodd, Hua, Crosbie, Holm, & Ozanne, 2002). Consonants produced
incorrectly
were consistent with the late-8 phonemes (Shriberg, 1993). Common phonological patterns were fricative simplification (82.5%), cluster simplification (49.0%)/reduction (19.6%), gliding (41.3%), and palatal fronting (15.4%). Interdental lisps on /s/ and /z/ were produced by 39.9% of the children, dentalization of other sibilants by 17.5%, and lateral lisps by 13.3%. Despite parent/teacher concern, only 41/109 children had contact with an SLP. These children were more likely to be unintelligible to strangers, to express distress about their speech, and to have a lower PCC and a smaller consonant inventory compared to the children who had no contact with an SLP.

Conclusion

A significant number of preschool-age children with speech sound disorders (SSD) have not had contact with an SLP. These children have mild-severe SSD and would benefit from SLP intervention. Integrated SLP services within early childhood communities would enable earlier identification of SSD and access to intervention to reduce potential educational and social impacts affiliated with SSD.
Line Spread as a Visual Clinical Tool for Thickened Liquids
Authors: Lund Annelise Masters , Garcia Jane Mertz , Chambers Edgar
Published: July 2013

Purpose

Preparing modified liquids to a target level of consistency is critical to patients' nutritional care. This study examined the relationship of line spread (i.e., the distance a liquid flows) to viscometer measurements for a variety of product/liquid combinations and determined if flow distance visually differentiated nectar-thick versus honey-like consistency.

Method

Combinations of 4 thickening products (3 starch-based and 1 gum-based thickener) prepared with 6 serving-temperature liquids that had various levels of fat, fiber, and added nutrients were tested. A total of 32 product/liquid combinations tested within the target range of 80–800 centipoise (cP). Measurements were recorded using line spread and a Brookfield RVDV-II+ viscometer.

Results

Nectar-thick and honey-like consistencies significantly differed in their degree of line spread. Using our line spread apparatus, a value of 4.5 cm differentiated between nectar-thick and honey-like consistencies. There was an inverse correlation (−.75) between viscometer data and line spread results. That is, high viscosity values represented samples with less flow distance (line spread), and low viscosity values represented samples with more flow distance.

Conclusion

Line spread appears to be a quick, objective, and visual method that might be used to help patients and their caregivers achieve more accurate and consistent thickened liquid preparation.
Direct magnetocaloric characterization and simulation of thermomagnetic cycles
Authors: Porcari G. , Buzzi M. , Cugini F. , Pellicelli R. , Pernechele C. , Caron L. , Brück E. , Solzi M.
Published: July 2013

An experimental setup for the direct measurement of the magnetocaloric effect capable of simulating high frequency magnetothermal cycles on laboratory-scale samples is described. The study of the magnetocaloric properties of working materials under operative conditions is fundamental for the development of innovative devices. Frequency and time dependent characterization can provide essential information on intrinsic features such as magnetic field induced fatigue in materials undergoing first order magnetic phase transitions. A full characterization of the adiabatic temperature change performed for a sample of Gadolinium across its Curie transition shows the good agreement between our results and literature data and in-field differential scanning calorimetry.
Conformational switching of modified guest chains in polymer brushes
Authors: Romeis D. , Sommer J.-U.
Published: July 2013

Using a numerical quasi off-lattice self-consistent field method which describes heterogeneous chains of spherical monomers we study the case of a densely grafted polymer brush with a fraction of free chain ends being replaced by a modified end-group differing in size and solvent selectivity. We can confirm the observation from molecular dynamics simulations that upon changing the solvent conditions, a switching in location of end-groups which are bigger than monomers from a state “exposed” to the solvent (on the top of the brush) to a “hidden” state (inside the brush) takes place. Our numerical method allows a detailed study of the switching effect as a function of the relevant parameters, such as grafting density, chain length, size of end-groups and their volume fraction. We find that the switching effect is enhanced for long chains, low fractions of modified chains, and big end-groups. We consider the case of low fraction of modified chains in more detail using a test chain method. Here, we explore the optimal grafting density as a function of the size of the end-groups, where the switching is most sensitive. These values can be in the experimental range for end-groups which are at least 3–4 times bigger than the monomers. The end-groups can be realized by attaching nano-particles to the last monomer of a brush-chain.
Origin of anomalous strain effects on the molecular adsorption on boron-doped graphene
Authors: Kang Joongoo , Kim Yong-Hyun , Glatzmaier Greg C. , Wei Su-Huai
Published: July 2013

When compressive strain is applied to a single-layered material, the layer generally ripples along the third dimension to release the strain energy. In contrast, such a rippling effect is not favored when it is under tensile strain. Here, using first-principles density-functional calculations, we show that molecular adsorption on boron-doped graphene (BG) can be largely tuned by exploiting the rippling effect of the strained graphene. Under tensile strain, the adsorption energy of K2CO3, NO2, and NH3 on BG, for which the molecular adsorption is a chemisorption characterized by a covalent B-molecule bond, exhibits a superlinear dependence on the applied strain. In contrast, when microscopic ripples are present in the BG under compressive strain, the adsorption strength is significantly enhanced with increasing the strain. Such a nonlinear and asymmetric effect of strain on the molecular adsorption is a characteristic of two-dimensional systems, because a general elastic theory of molecular adsorption on three-dimensional systems gives a linear and symmetric strain effect on the adsorption strength. We provide the underlying mechanism of the anomalous strain effect on the chemical molecular adsorption on BG, in which the microscopic rippling of the graphene and the creation of the π-dangling bond state near the Dirac point play an important role. Our finding can be used to modify chemical reactivity of graphene with a wide range of application.
Critical fluctuations in DOPC/DPPC-d62/cholesterol mixtures: 2H magnetic resonance and relaxation
Authors: Davis James H. , Ziani Latifa , Schmidt Miranda L.
Published: July 2013

Static and magic angle spinning (MAS) 2H nuclear magnetic resonance experiments have been performed on a series of multilamellar dispersions of di-oleoyl-sn-glycero-3-phosphocholine/di-palmitoyl-sn-glycero-3-phosphocholine-d62/cholesterol in water to investigate the compositional fluctuations which occur in the region of the line of critical points for this ternary system. The strong dependence of the MAS line widths on temperature, sample composition, and spinning rate provides a direct measure of the magnitude of the fluctuations in the 2H quadrupolar Hamiltonian. These data are analyzed in terms of models for critical fluctuations in composition leading to a value for the critical index for the correlation length, νc = 0.628, consistent with a three dimensional Ising model.
High transition temperature superconductor/insulator bilayers for the development of ultra-fast electronics
Authors: Sirena M. , Félix L. Avilés , Haberkorn N.
Published: July 2013

High transition temperature superconductor (HTc)/SrTiO3 (STO) bilayers were fabricated by sputtering deposition on (100) STO substrates. Their transport and morphological properties were characterized using conductive atomic force microscopy. The STO barriers present good insulating properties, with long attenuation lengths (λ ∼ 1 nm) which reduce the junction resistance and increase the operating critical current. The samples present roughness values smaller than 1 nm, with an extremely low density of surface defects (∼5 × 10−5 defects/μm2). The high control of the barrier quality over large defect free surfaces is encouraging for the development of microelectronics devices based in HTc Josephson junctions.
Competition enhances stochasticity in biochemical reactions
Authors: Firman Taylor , Ghosh Kingshuk
Published: July 2013

We study stochastic dynamics of two competing complexation reactions (i) A + B↔AB and (ii) A + C↔AC. Such reactions are common in biology where different reactants compete for common resources – examples range from binding enzyme kinetics to gene expression. On the other hand, stochasticity is inherent in biological systems due to small copy numbers. We investigate the complex interplay between competition and stochasticity, using coupled complexation reactions as the model system. Within the master equation formalism, we compute the exact distribution of the number of complexes to analyze equilibrium fluctuations of several observables. Our study reveals that the presence of competition offered by one reaction (say A + C↔AC) can significantly enhance the fluctuation in the other (A + B↔AB). We provide detailed quantitative estimates of this enhanced fluctuation for different combinations of rate constants and numbers of reactant molecules that are typical in biology. We notice that fluctuations can be significant even when two of the reactant molecules (say B and C) are infinite in number, maintaining a fixed stoichiometry, while the other reactant (A) is finite. This is purely due to the coupling mediated via resource sharing and is in stark contrast to the single reaction scenario, where large numbers of one of the components ensure zero fluctuation. Our detailed analysis further highlights regions where numerical estimates of mass action solutions can differ from the actual averages. These observations indicate that averages can be a poor representation of the system, hence analysis that is purely based on averages such as mass action laws can be potentially misleading in such noisy biological systems. We believe that the exhaustive study presented here will provide qualitative and quantitative insights into the role of noise and its enhancement in the presence of competition that will be relevant in many biological settings.
Indium outdiffusion and leakage degradation in metal/Al2O3/In0.53Ga0.47As capacitors
Authors: Krylov Igor , Gavrilov Arkady , Eizenberg Moshe , Ritter Dan
Published: July 2013

Annealing of Ni/Al2O3/InGaAs structures results in a significant increase of the leakage current. The same treatment of Au/Ti/Al2O3/InGaAs structures results in a slight increase in leakage only. Time of flight secondary ions mass spectrometry measurements detected an annealing induced indium outdiffusion into the dielectric layer. In structures having nickel metallization, the released indium accumulated at the Ni/Al2O3 interface. In structures having Au/Ti metallization, the indium atoms penetrated into the gold layer, and an indium free Al2O3 layer was observed. We attribute the observed different electrical behavior to the different indium diffusion behavior, and eliminate other explanations.
Modeling charge transport in quantum dot light emitting devices with NiO and ZnO transport layers and Si quantum dots
Authors: Kumar Brijesh , Campbell Stephen A. , Paul Ruden P.
Published: July 2013

We propose a model for quantum dot light emitting devices (QD-LEDs), which explores the most important parameters that control their electrical characteristics. The device is divided into a hole transport layer, several quantum dot layers, and an electron transport layer. Conduction and recombination in the central quantum dot region is described by a system of coupled rate equations, and the drift-diffusion approximation is used for the hole and electron transport layers. For NiO/Si-QDs/ZnO devices with suitable design parameter, the current and light output are primarily controlled by the quantum dot layers, specifically, their radiative and non-radiative recombination coefficients. Radiative recombination limits the device current only at sufficiently large bias.
The effects of interface misfit strain and surface tension on magnetoelectric effects in layered magnetostrictive-piezoelectric composites
Authors: Hao Feng , Pei Yongmao , Fang Daining
Published: July 2013

A nonlinear model is proposed to study low-frequency magnetoelectric (ME) effects in layered magnetostrictive-piezoelectric composites, taking into account the effects of interface misfit strain and surface stress. As a specific case, L-T mode of Terfenol-D/lead zirconate titanate (PZT) composites is investigated. The results show that flexural deformation can suppress the ME voltage coefficient, especially for elevated Terfenol-D volume fraction. Interface misfit strain demonstrates a notable impact on the ME voltage coefficient, and this strain-mediated ME effect is intensified with increasing interface misfit strain. Owing to residual surface tension, the ME voltage coefficient is found to be size-dependent when the thickness of Terfenol-D/PZT layered composite reduces to the nanoscale. In addition, substrate effect on ME voltage coefficients is evaluated.
Interactions between ultrasound stimulated microbubbles and fibrin clots
Authors: Acconcia Christopher , Leung Ben Y. C. , Hynynen Kullervo , Goertz David E.
Published: July 2013

While it is well established that ultrasound stimulated microbubbles (USMBs) can potentiate blood clot lysis, the mechanisms are not well understood. Here we examine the interaction between USMBs and fibrin clots, which are comprised of fibrin networks that maintain the mechanical integrity of blood clots. High speed camera observations demonstrated that USMBs can penetrate fibrin clots. Two-photon microscopy revealed that penetrating bubbles can leave behind patent “tunnels” along their paths and that fluid can be transported into the clots. Finally, it is observed that primary radiation forces associated with USMBs can induce local deformation and macroscopic translation of clot boundaries.
One-step growth of vertical graphene sheets on carbon nanotubes and their field emission properties
Authors: Liu Jianlong , Zeng Baoqing , Wang Xiangru , Wang Wenzhong , Shi Honglong
Published: July 2013

Graphene-carbon nanotube hybrid is prepared by an in situ growth of vertical graphene sheets on carbon nanotubes (CNTs), using one-step plasma-enhanced chemical vapor deposition, without catalyst. TEM analysis indicates that the growth of graphene is in accordance with the defects of carbon nanotubes introduced by high-energy ion bombardment in microwave plasma and expands by epitaxial growth. The results suggest that the method is ideal for preparing uniform graphene-carbon nanotube hybrid and demonstrate a categorical explanation for the growth mechanism of graphene-CNTs hybrid. Because of its uniform networks and multistage structure, the graphene-CNTs hybrid exhibits good field emission properties.
Noise thermometry at ultra low temperatures
Authors: Rothfuß D. , Reiser A. , Fleischmann A. , Enss C.
Published: July 2013

We present a contact free cross-correlation noise thermometer experimentally characterized for temperatures between 0.8 K and 45 μK. The noise source is a cold-worked copper cylinder. The fluctuations of magnetic fields due to the thermal motion of the electrons in the copper cylinder are simultaneously monitored by two superconducting quantum interference device magnetometers. A subsequent cross-correlation of both channels reduces the noise contribution of the amplifiers by more than one order of magnitude. This technique covers almost five orders of magnitude in temperature including ultra low temperatures, which were accessible only by platinum nuclear magnetic resonance thermometers so far.
Fe3O4 films on Ag(001)—Generation of high-quality epitaxial ferrimagnetic metal oxide films
Authors: Bruns D. , Lindemann S. R. , Kuepper K. , Schemme T. , Wollschläger J.
Published: July 2013

A well-ordered Fe film epitaxially grown on Ag(001) has been applied to different post deposition treatments of oxidation and post oxidation annealing. The structure of the film and its surface has been investigated by x-ray diffraction and low energy electron diffraction, while x-ray photoelectron spectroscopy is used to determine the film stoichiometry. A first oxidation step at moderate temperature leads to a badly ordered Fe2O3 film. The structure of the film is improved by additional annealing at increased temperature. Finally, a well-ordered Fe3O4 film is obtained with well developed magnetic properties as proved by vector magneto optical Kerr effect experiments.
Surface transport properties of Fe-based superconductors: The influence of degradation and inhomogeneity
Authors: Plecenik T. , Gregor M. , Sobota R. , Truchly M. , Satrapinskyy L. , Kurth F. , Holzapfel B. , Iida K. , Kus P. , Plecenik A.
Published: July 2013

Surface properties of Co-doped BaFe2As2 epitaxial superconducting thin films were inspected by X-ray photoelectron spectroscopy, scanning spreading resistance microscopy (SSRM), and point contact spectroscopy (PCS). It has been shown that surface of Fe-based superconductors degrades rapidly if being exposed to air, what results in suppression of gap-like structure on PCS spectra. Moreover, SSRM measurements revealed inhomogeneous surface conductivity, what is consistent with strong dependence of PCS spectra on contact position. Presented results suggest that fresh surface and small probing area should be assured for surface sensitive measurements like PCS to obtain intrinsic properties of Fe-based superconductors.
Periodic diffraction correlation imaging through strongly scattering mediums
Authors: Li Hu , Shi Jianhong , Zhu Yongchao , Zeng Guihua
Published: July 2013

We demonstrate an experiment of imaging through a scattering layer based on periodic diffraction correlation imaging. No matter the scattering layer is immobile or vibratory, multiple images can be periodically obtained in the uncovered zones by periodic diffraction correlation imaging. The implementation of this experiment is quite simple and low-cost. This technique could find applications in imaging biological tissues.
Influence of a Ta spacer on the magnetic and transport properties of perpendicular magnetic tunnel junctions
Authors: Cuchet Léa , Rodmacq Bernard , Auffret Stéphane , Sousa Ricardo C. , Ducruet Clarisse , Dieny Bernard
Published: July 2013

Ultrathin Ta layers were inserted in the bottom hard (Co/Pt)/Ta/CoFeB/MgO magnetic electrode of perpendicular magnetic tunnel junctions. The magnetization of the top part of this electrode abruptly falls in-plane when the Ta thickness exceeds 0.45 nm. This results from the balance between the various energy terms acting on this layer (exchange-like coupling through Ta, demagnetizing energy, and perpendicular anisotropy at the CoFeB/MgO interface). For small Ta thicknesses, this insertion leads to a strong improvement of the tunnel magnetoresistance, as long as the magnetization of all layers remains perpendicular-to-plane.
Band gap prediction for composition-tunable alloyed semiconductor nanocrystals
Authors: Gao Lihua , Gao Faming
Published: July 2013

Size and composition-dependences of band gap energies are important properties for nanocrystal semiconductors, and have attracted extensive attentions for the last two decades. In this letter, a simple method of band gap prediction for nanocrystal alloys is developed. The band gaps of II–VI semiconductor homogeneous alloys with zinc blende and wurtzite structure, such as zb-(ZnS)x(CdS)1−x, zb-(CdS)x(CdSe)1−x, zb-(ZnSe)x(CdSe)1−x, w-(ZnS)x(CdS)1−x, w-(ZnSe)x(CdSe)1−x, and w-(CdSe)x(CdTe)1−x nanocrystal alloys, are calculated. The calculated results are in good agreement with the available experimental data. It provides insights into the effects of structure, size, and composition on the band gap.
Contact-free pyroelectric measurements using x-ray photoelectron spectroscopy
Authors: Ehre D. , Cohen H.
Published: July 2013

Non-contact pyroelectricity measurements based on x-ray photoelectron spectroscopy (XPS) are presented. Applied to Lithium Tantalate crystals, we demonstrate how the XPS-derived surface potential provides a simple probe of the desired property, free of all top-contact related difficulties. In particular, the increase in Lithium Tantalate spontaneous polarization under cooling, an experimentally challenging feature, is evaluated. We further inspect the roll of surface contaminants and the control over trapped surface charge in the XPS vacuum environment. Our approach can be extended to other non-contact probes, as well as to measuring additional electrical properties, such as piezoelectricity and ferroelectricity.
Micro-superconducting quantum interference devices based on V/Cu/V Josephson nanojunctions
Authors: Ronzani Alberto , Baillergeau Matthieu , Altimiras Carles , Giazotto Francesco
Published: July 2013

We report on the fabrication and characterization of micrometer-sized superconducting quantum interference devices (SQUIDs) based on nanoscale vanadium/copper/vanadium Josephson weak links. Magnetically driven quantum interference patterns have been measured for temperatures in the 0.24–2 K range. As DC SQUIDs, these devices obtain flux-to-voltage transfer function values as high as 450 μV/Φ0 leading to promising magnetic flux resolution ΦN<3 μΦ0/Hz, being here limited by the room temperature preamplification stage. Significant improvement in the flux noise performance figures is expected with the adoption of cryogenic preamplification. The presented devices are suitable for operation as small-area SQUIDs at sub-Kelvin temperature, but their design can also be upscaled to include input coils enabling their use as sensitive magnetometers via the adoption of optimized electronic readout stages based on flux feedback schemes.
Ultra-low switching power, crystallographic analysis, and switching mechanism for SnXTe100−X/Sb2Te3 diluted superlattice system
Authors: Soeya Susumu , Shintani Toshimichi , Odaka Takahiro , Kondou Reiko , Tominaga Junji
Published: July 2013

Ultra-low switching power (∼1/50th–1/2250th that of a Ge2Sb2Te5 device) was obtained in a SnXTe100−X/Sb2Te3 diluted superlattice (SL) device (X = 10, 20, and 35 at. %). XRD analysis showed that there was little coexistence of the SnTe/Sb2Te3 SL, Bi2Te3-type SnSbTe-alloy and Te phases. Detailed crystallographic analysis showed that there is a high probability that the SnSbTe-alloy phase independently changed into a SL structure. This self-assembled SL structure had a vacancy layer in a specific Te layer. Some phenomenon, such as Sn switching, in the self-assembled SL might lead to the ultra-low switching power.
Structural characterization of {101¯2} twin boundaries in cobalt
Authors: Tu Jian , Zhang Xiyan , Wang Jian , Sun Q. , Liu Qing , Tomé Carlos N
Published: July 2013

Using high-resolution transmission electron microscopy, we characterized the structures of {101¯2} deformation twin boundaries (TBs) in cobalt and found that TBs consist of {101¯2} coherent twinning boundaries and basal-prismatic interfaces (BPs or PBs). According to these structural features, the propagation of {101¯2} twins cannot be simply accomplished through the glide-shuffle mechanism of twinning dislocations. Correspondingly, two migration mechanisms of such TBs are proposed based on dislocation theory. In addition, abundant basal stacking faults are observed experimentally to connect with TBs, and this phenomenon is ascribed to the release of residual dislocations resulting from the migration of the BPs and PBs.
Communication: Fundamental equation of state correlation with hybrid data sets
Authors: Rutkai G. , Thol M. , Lustig R. , Span R. , Vrabec J.
Published: July 2013

A strategy is proposed for empirical fundamental equation of state correlations for pure fluids on the basis of hybrid data sets, composed of experimental and molecular simulation data. Argon and hydrogen chloride are used as examples.
A phenotypic marker for quantifying heat stress impact during microsporogenesis in rice (Oryza sativa L.)
Authors: Jagadish Krishna S. V. , Craufurd Peter , Shi Wanju , Oane Rowena
Published: July 2013

Gametogenesis in rice (Oryza sativa L.), and particularly male gametogenesis, is a critical developmental stage affected by different abiotic stresses. Research on this stage is limited, as flowering stage has been the major focus for research to date. Our main objective was to identify a phenotypic marker for male gametogenesis and the duration of exposure needed to quantify the impact of heat stress at this stage. Spikelet size coinciding with microsporogenesis was identified using parafilm sectioning, and the panicle (spikelet) growth rate was established. The environmental stability of the marker was ascertained with different nitrogen (75 and 125 kg ha–1) and night temperature (22°C and 28°C) combinations under field conditions. A distance of –8 to –9 cm between the collar of the last fully opened leaf and the flag leaf collar, which was yet to emerge was identified as the environmentally stable phenotypic marker. Heat stress (38°C) imposed using the identified marker induced 8–63% spikelet sterility across seven genetically diverse rice genotypes. Identifying the right stage based on the marker information and imposing 6 consecutive days of heat stress ensures that >95% of the spikelets in a panicle are stressed spanning across the entire microsporogenesis stage.
Coding Gene Single Nucleotide Polymorphism Population Genetics of Nonnative Brook Trout: The Ghost of Introductions Past
Authors: Neville H. M. , Bernatchez L.
Published: July 2013

Fish have been translocated throughout the world, and introductions often have been executed repeatedly and have used mixtures of different strains from the native range. This history might have contributed to their invasive potential by allowing introduced and invading populations to circumvent expected reductions in genetic diversity from founder effects in a scenario termed the “genetic paradox” of invasions. We characterize patterns of genetic diversity in nonnative Brook Trout Salvelinus fontinalis, which have been introduced across the western United States for over a century but have also invaded broadly and pose a primary threat to native trout. We analyzed 155 coding gene single nucleotide polymorphisms (SNPs) in 34 nonnative Brook Trout populations sampled across eight large river systems as well as samples from the only four hatchery strains with documented use in Idaho. We uncovered similar within‐population genetic diversity and large effective population sizes in naturalized populations compared with hatchery samples. Naturalized populations also showed substantial genetic structuring (maximum pairwise FST = 0.23) across and even within watersheds and indicated suggestions of admixture in certain regions. Assignment probabilities confirmed two main hatcheries as the origin of most fish collected in the field; however, the four hatcheries were excluded as being the origin for 8% of individuals, mirroring results from clustering analyses and suggesting the influence of an additional unsampled hatchery source or sources. Simulated admixtures of hatchery samples produced genetic patterns similar to those observed in field samples, further supporting an influence of multiple historic hatchery stocks on the contemporary genetic structure of Brook Trout in Idaho. Our study highlights the potential contribution of historic hatchery and introduction practices in creating genetically variable and structured naturalized Brook Trout populations across Idaho, which may have allowed these fish to defy the “genetic paradox” early on in their nonnative history and set the stage for successful establishment and subsequent invasion.
Identification of Largemouth Bass Virus in the Introduced Northern Snakehead Inhabiting the Chesapeake Bay Watershed
Authors: Iwanowicz L. , Densmore C. , Hahn C. , McAllister P. , Odenkirk J.
Published: July 2013

The Northern Snakehead Channa argus is an introduced species that now inhabits the Chesapeake Bay. During a preliminary survey for introduced pathogens possibly harbored by these fish in Virginia waters, a filterable agent was isolated from five specimens that produced cytopathic effects in BF-2 cells. Based on PCR amplification and partial sequencing of the major capsid protein (MCP), DNA polymerase (DNApol), and DNA methyltransferase (Mtase) genes, the isolates were identified as Largemouth Bass virus (LMBV). Nucleotide sequences of the MCP (492 bp) and DNApol (419 pb) genes were 100% identical to those of LMBV. The nucleotide sequence of the Mtase (206 bp) gene was 99.5% identical to that of LMBV, and the single nucleotide substitution did not lead to a predicted amino acid coding change. This is the first report of LMBV from the Northern Snakehead, and provides evidence that noncentrarchid fishes may be susceptible to this virus.

Received April 8, 2013; accepted April 19, 2013
Neurotoxic unc-8 mutants encode constitutively active DEG/ENaC channels that are blocked by divalent cations
Authors: Wang Ying , Matthewman Cristina , Han Lu , Miller Tyne , Miller David M. , Bianchi Laura
Published: July 2013

Ion channels of the DEG/ENaC family can induce neurodegeneration under conditions in which they become hyperactivated. The Caenorhabditis elegans DEG/ENaC channel MEC-4(d) encodes a mutant channel with a substitution in the pore domain that causes swelling and death of the six touch neurons in which it is expressed. Dominant mutations in the C. elegans DEG/ENaC channel subunit UNC-8 result in uncoordinated movement. Here we show that this unc-8 movement defect is correlated with the selective death of cholinergic motor neurons in the ventral nerve cord. Experiments in Xenopus laevis ooctyes confirm that these mutant proteins, UNC-8(G387E) and UNC-8(A586T), encode hyperactivated channels that are strongly inhibited by extracellular calcium and magnesium. Reduction of extracellular divalent cations exacerbates UNC-8(G387E) toxicity in oocytes. We suggest that inhibition by extracellular divalent cations limits UNC-8 toxicity and may contribute to the selective death of neurons that express UNC-8 in vivo.
Series representation of the Riemann zeta function and other results: Complements to a paper of Crandall
Authors: Coffey Mark
Published: July 2013

We supplement a very recent paper of R. Crandall concerned with the multiprecision computation of several important special functions and numbers. We show an alternative series representation for the Riemann and Hurwitz zeta functions providing analytic continuation throughout the whole complex plane. Additionally, we demonstrate some series representations for the initial Stieltjes constants appearing in the Laurent expansion of the Hurwitz zeta function. A particular point of elaboration in these developments is the hypergeometric form and its equivalents for certain derivatives of the incomplete Gamma function. Finally, we evaluate certain integrals including

∫

\tiny {Re}

s
=
c

ζ
(
s
)

s

d
s

\int _{\mbox {\tiny {Re}} s=c} {{\zeta (s)} \over s} ds

and

∫

\tiny {Re}

s
=
c

η
(
s
)

s

d
s

\int _{\mbox {\tiny {Re}} s=c} {{\eta (s)} \over s} ds

, with

ζ
\zeta

the Riemann zeta function and

η
\eta

its alternating form.
Bronisław Malinowski
Authors: Holdsworth Chris
Published: July 2013

Bronisław Malinowski (b. 1884–d. 1942) is arguably the most influential anthropologist of the 20th century, certainly for British social anthropology. The list of his students is a who’s who of the most important British anthropologists of the 1930s through to the 1970s and includes, among others, Raymond Firth, E. E. Evans-Pritchard, Audrey Richards, Edmund Leach, Ashley Montagu, Meyer Fortes, and Isaac Schapera. Malinowski saw himself as effecting a revolution in anthropology by rejecting the evolutionary paradigm of his predecessors and introducing functionalism, whereby institutions satisfied human biological needs, as the way to understand other cultures. His lasting legacy, however, is methodological rather than theoretical. It was by exhorting anthropologists to give up their comfortable position on the veranda of the missionary compound or government station and to go and live and work with the people they studied that he effected his real innovation: fieldwork. Although not the first to conduct fieldwork, his lengthy stay among the Trobriand Islanders during World War I established, as Edmund Leach (in Singer 2011, cited under Documentaries) has remarked, how to “do” anthropology. Living with the people he studied, getting to know them personally, participating in their activities, and conducting his research in the vernacular has since become known as participant observation. His collection of monographs and numerous articles on the Trobriand Islanders is perhaps the most extensive ethnography of any people written to date. His magnum opus, Argonauts of the Western Pacific, published in 1922, in which he describes the Kula ring (a complex interisland exchange of arm shell bracelets and necklaces), is one of the first modern ethnographies. Unlike earlier monographs, which were dry catalogues of facts, Malinowski’s ethnographies painted a romantic picture of native life, had an institutional focus, and provided a vivid narrative where the ethnographer is seen to interact with real people. A prolific writer, Malinowski tackled some of the most important and controversial topics of his day: economics, religion, family, sex, psychology, colonialism, and war. He insisted that a proper understanding of culture required viewing these various aspects in context. Malinowski was instrumental in transforming British social anthropology from an ethnocentric discipline concerned with historical origins and based on the writings of travelers, missionaries, and colonial administrators to one concerned with understanding the interconnections between various institutions and based on fieldwork, where the goal was to “grasp the native’s point of view” (Malinowski 1984, p. 25, cited under Fieldwork and Ethnography).
Natural Variation in Maize Aphid Resistance Is Associated with 2,4-Dihydroxy-7-Methoxy-1,4-Benzoxazin-3-One Glucoside Methyltransferase Activity
Authors: Meihls Lisa N. , Handrick Vinzenz , Glauser Gaetan , Barbier Hugues , Kaur Harleen , Haribal Meena M. , Lipka Alexander E. , Gershenzon Jonathan , Buckler Edward S. , Erb Matthias , Köllner Tobias G. , Jander Georg
Published: July 2013

Plants differ greatly in their susceptibility to insect herbivory, suggesting both local adaptation and resistance tradeoffs. We used maize (Zea mays) recombinant inbred lines to map a quantitative trait locus (QTL) for the maize leaf aphid (Rhopalosiphum maidis) susceptibility to maize Chromosome 1. Phytochemical analysis revealed that the same locus was also associated with high levels of 2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one glucoside (HDMBOA-Glc) and low levels of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one glucoside (DIMBOA-Glc). In vitro enzyme assays with candidate genes from the region of the QTL identified three O-methyltransferases (Bx10a-c) that convert DIMBOA-Glc to HDMBOA-Glc. Variation in HDMBOA-Glc production was attributed to a natural CACTA family transposon insertion that inactivates Bx10c in maize lines with low HDMBOA-Glc accumulation. When tested with a population of 26 diverse maize inbred lines, R. maidis produced more progeny on those with high HDMBOA-Glc and low DIMBOA-Glc. Although HDMBOA-Glc was more toxic to R. maidis than DIMBOA-Glc in vitro, BX10c activity and the resulting decline of DIMBOA-Glc upon methylation to HDMBOA-Glc were associated with reduced callose deposition as an aphid defense response in vivo. Thus, a natural transposon insertion appears to mediate an ecologically relevant trade-off between the direct toxicity and defense-inducing properties of maize benzoxazinoids.
Mineralocorticoid receptor and cardiac arrhythmia
Authors: Gravez Basile , Tarjus Antoine , Jaisser Frederic
Published: July 2013

Mineralocorticoid receptor (MR) activation has been shown to play a deleterious role in the development of heart disease in studies using specific MR antagonists (spironolactone, eplerenone) in both experimental models and patients. Pharmacological MR blockade attenuates the transition to heart failure (HF) in models of systolic left ventricular dysfunction and myocardial infarction, as well as diastolic dysfunction, in rats and mice. In humans, MR antagonism is highly beneficial in patients with mild or advanced HF and postinfarct HF. The consequences of aldosterone and MR activation for cardiac arrhythmia and its prevention and/or correction by MR antagonists are often underestimated.

 Activation of MR modulates cardiac electrical activity, causing atrial and ventricular arrhythmias. A pro‐arrhythmogenic effect of aldosterone (possibly partly dependent on fibrosis) has been suggested by several studies. Cardiac MR activation has important consequences for the control of cellular calcium homeostasis, action potential lengthening, modulation of calcium transients and sarcoplasmic reticulum diastolic leaks, resulting in the promotion of rhythm disorders. Aldosterone and/or MR activation (in both cardiomyocytes and coronary vessels) result in vascular dysfunction and also contribute to pro‐arrhythmogenic conditions.

 Together, the pro‐arrhythmic effects of aldosterone and/or MR may explain the highly beneficial effect of MR antagonism, namely a decrease in the incidence of sudden death, observed in the Randomized Aldactone Evaluation Study (RALES) and Eplerenone Post‐Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS) studies.
Linguistic and pragmatic skills in toddlers with cochlear implant
Authors: Rinaldi Pasquale , Baruffaldi Francesca , Burdo Sandro , Caselli Maria Cristina
Published: July 2013

Background

An increasing number of deaf children received cochlear implants (CI) in the first years of life, but no study has focused on linguistic and pragmatic skills in children with CI younger than 3 years of age.

Aims

To estimate the percentage of children who had received a CI before 2 years of age whose linguistic skills were within the normal range; to compare linguistic skills of children implanted by 12 months of age with children implanted between 13 and 26 months of age; and to describe the relationship among lexical, grammar and pragmatic skills.

Methods & Procedures

The participants consisted of children who were included on the patient lists of the Service of Audio‐Vestibology of the Circolo Hospital in Varese, Italy, and met the following criteria: chronological age between 18 and 36 months; CI activated between 8 and 30 months of age; absence of other reported deficits; hearing parents; and not less than 6 months of CI experience. Language development was evaluated through MacArthur–Bates CDI; pragmatic skills (assertiveness and responsiveness) were evaluated through the Social Conversational Skills Rating Scale. The scores obtained were transformed into z‐scores and compared with normative data. The relationship among lexical, grammar and pragmatic skills were tested using Spearman Rho correlations. Children with CI were divided into groups based on the age at CI activation and the differences between the two groups were tested using the Student's t‐test.

Outcomes & Results

Data from 23 deaf children were collected. Fewer than half of the children were within the normal range for lexical production and use of sentences; more than one‐third of them fell below the normal range for both lexical and grammar skills. No significant difference was found in vocabulary size or early grammar skills when comparing children who received the CI by 12 months of age with those implanted during the second year of life. Despite the strong relationship among lexical, grammar and pragmatic skills, the delays found for grammar and pragmatic skills were greater than expected based on the vocabulary size. Age at diagnosis of hearing loss was the only predictor of vocabulary size.

Conclusions & Implications

CI may provide deaf children with a good opportunity to develop language skills, but severe difficulties in early social experiences and interaction mediated by language still remain. Delays in these aspects suggest that interventions improving pragmatic skills are recommended even on very young children with CI.
What Role for Social Science in the ‘Urban Age'?
Authors: Gleeson Brendan
Published: July 2013

There is growing recognition of a new human ascendancy: ‘the urban age’. Rising interest in urbanism is evident in popular literature, the media and major global institutions. And yet, as with another great issue of the age, global warming, there is evidence that social science is being sidelined from a rapidly enlarging field of human concern. New urban knowledges are forwarded from the physical sciences and from popular commentary that are characterized by naturalism and its kindred tendencies, especially determinism. In this essay I consider why social scientific urbanism seems increasingly marginal to an ever broadening urban discussion. The regressive consequences for human knowledge and prospect are essayed. The essay's final part is prospectus: for a revivified social scientific urbanism that draws from Sayer's recent argument for renewal of critical human knowledge.