bluuebunny/crossref_metadata_2025 huggingface dataset:
Nuclear safeguards: 1. The IAEA program
Authors: Sharpe Bernard W.
Published: January 2009

WITH THE SIGNING of the Treaty on the Nonproliferation of Nuclear Weapons (NPT), the International Atomic Energy Agency will become responsible for ensuring that nations without nuclear weapons do not acquire them. The IAEA Department of Safeguards and Inspection has for many years been making inspections to ensure that nuclear material being used for peaceful purposes is not diverted for weapons production.
States of aggregation
Authors: Mendelssohn Kurt
Published: January 2009

SUPERFLUIDITY and superconductivity (figures 1 and 2) can be discussed in terms of a subject much older than either: states of aggregation.
Hot Water Source in Space May Act as Maser
Authors: Lubkin Gloria B.
Published: January 2009

Water molecules have been found in the interstellar medium and appear to be acting like masers, according to a research team at Berkeley (Albert C. Cheung, David Rank, Charles Townes, Douglas Thornton, William Welch) and the Naval Research Laboratory (Cornell Mayer and Stephen Knowles). By microwave observations with the 20-foot Hat Creek radio telescope and then the 85-foot NRL radio telescope, which gave more directivity, the group found water in eight different regions (Nature 221, 626, 1969 and Science 163, 1055, 1969).
A Visit to Arecibo Finds a Telescope Seeking Improvement
Authors: Ellis R. Hobart
Published: January 2009

The cable car looks not on white slopes and prancing skiers but on the tropical green and brown of Puerto Rican forests. At the top terminus you can look straight down a distance equal to the height of the Washington monument. You look into the center of the world's largest dish—18 acres of wire mesh on a carefully positioned spherical network of supporting cables. You walk around on a 500-ton assembly that supports two carriage houses, a workshop, cables, waveguides and motors to turn and slide its various parts. Below extend the horns, snouts and Yagi antennas that can transmit and receive radio frequencies between 20 and 600 megahertz. A few miles south of the northern coast of Puerto Rico, this is the radar and radio telescope of the Arecibo Ionospheric Observatory. It was dedicated in 1963 (PHYSICS TODAY, January 1964, page 66).
The origin of the elements
Authors: Clayton Donald D.
Published: January 2009

THE NUCLEAR THEORY of the origin of the elements, commonly called nucleosynthesis, is the attempt to interpret the abundances of nuclear species in terms of their nuclear properties and the naturally occurring circumstances in which the nuclei would be assembled. We have a very sizable body of data to guide the construction of the theory and to test its success. There are 81 stable elements, with numbers of stable isotopes ranging from one for sodium, for example, to ten for tin; they comprise a total of 280 stable nuclear species. The abundances of these species in the solar system constitute 280 data points for the theory, to which must be added all observable abundance ratios in other stars.
Particles beyond the light barrier
Authors: Bilaniuk Olexa-Myron , Sudarshan E. C. George
Published: January 2009

FOR MANY DECADES now the view has prevailed that no particle could possibly travel with a velocity greater than the velocity of light in vacuum, c = 3×108 m/sec. It is generally held that this limitation is a direct consequence of the special theory of relativity. Albert Einstein himself has said so in his original paper on relativity.
Correlation between structural and low-temperature thermoelectric properties of Zn13+xSb10 compounds
Authors: Nakamoto Go , Kinoshita Keisuke , Kurisu Makio
Published: January 2009

Structural, metallurgical, and low-temperature thermoelectric properties have been investigated for Zn13+xSb10 compounds prepared by the gradient freeze and vacuum melt-quench methods at various starting Zn compositions. The Rietveld analysis of the powder x-ray diffraction profiles indicates that the excess Zn occupies mainly the 36f-3 and 36f-4 interstitial sites. It is also revealed that the actual Zn composition and lattice constants have strong correlation with occupation factors of the 36f-3 and 36f-4 sites. The thermoelectric property strongly depends on the actual Zn composition. The enhancement in the electrical resistivity and Seebeck coefficient associated with the β to α structural phase transition is more remarkable for the samples with larger starting Zn composition. On the other hand, the lattice thermal conductivity also exhibits a remarkable increase at the transition temperature, indicating an ordered Zn structure in the α phase. These facts indicate that the occupation of Zn in the two interstitial 36f-3 and 36f-4 sites gives a significant effect on the crystal and electronic structures of the Zn13+xSb10 system.
Generalized instantons on complex projective spaces
Authors: Kihara Hironobu , Nitta Muneto
Published: January 2009

We study a class of generalized self-duality relations in gauge theories on the complex projective space with the Fubini–Study metric. Our theories consist of only gauge fields with gauge group U(n). The pseudoenergies which we consider contain higher orders of field strength and are labeled by an integer p smaller than or equal to [n/2]. For making the Bogomol’nyi completion we need nonsingle trace terms in the pseudoenergies, unlike the models defined on spheres, which were studied previously. We construct an explicit solution in dimension 2n to generalized self-duality equations as Bogomol’nyi equations by using a part of the spin connection.
Few-cycle laser pulses to obtain spatial separation of OHF− dissociation products
Authors: Elghobashi-Meinhardt Nadia , González Leticia , Barth Ingo , Seideman Tamar
Published: January 2009

In a two-part theoretical study, field-free orientation of OHF− is achieved by means of moderately intense half-cycle, infrared laser pulses. In the first step, a short linearly polarized pulse excites a superposition of rigid rotor rotational eigenstates via interaction with the permanent dipole moment of OHF−. After the field has been switched off, pronounced molecular orientation is observed for several picoseconds. In the second step, femtosecond few-cycle laser pulses are applied to the oriented system to steer vibrational dynamics, modeled by anharmonic vibrational wave functions calculated on a potential energy surface obtained with unrestricted fourth order Møller-Plesset ab initio calculations. The result is selective bond breaking of OHF, followed by the spatial separation of dissociation products in the space-fixed frame. Due to revivals in the rotational wavepacket, product yields can be enhanced over long times.
Time evolution of dynamic propensity in a model glass former: The interplay between structure and dynamics
Authors: Fris J. A. Rodriguez , Alarcón L. M. , Appignanesi G. A.
Published: January 2009

By means of the isoconfigurational method, we calculate the change in the propensity for motion that the structure of a glass-forming system experiences during its relaxation dynamics. The relaxation of such a system has been demonstrated to evolve by means of rapid crossings between metabasins of its potential energy surface (a metabasin being a group of mutually similar, closely related structures which differ markedly from other metabasins), as collectively relaxing units (d-clusters) take place. We now show that the spatial distribution of propensity in the system does not change significantly until one of these d-clusters takes place. However, the occurrence of a d-cluster clearly decorrelates the propensity of the particles, thus ending up with the dynamical influence of the structural features proper of the local metabasin. We also show an important match between particles that participate in d-clusters and that which show high changes in their propensity.
The partition function of the two-matrix model as an isomonodromic τ function
Authors: Bertola M. , Marchal O.
Published: January 2009

We consider the Itzykson–Zuber–Eynard–Mehta two-matrix model and prove that the partition function is an isomonodromic τ function in a sense that generalizes that of Jimbo et al. [ “Monodromy preserving deformation of linear ordinary differential equations with rational coefficients,” Physica D 2, 306 (1981)]. In order to achieve the generalization we need to define a notion of τ function for isomonodromic systems where the adregularity of the leading coefficient is not a necessary requirement.
Blend composition study of poly(3,3‴-didodecylquaterthiophene)/[6,6]-phenyl C61 butyric acid methyl ester solution processed organic solar cells
Authors: Yuen Avery P. , Preston John S. , Hor Ah-Mee , Klenkler Richard , Macabebe Erees Queen B. , Ernest van Dyk E. , Loutfy Rafik O.
Published: January 2009

Photovoltaic devices made from blends of poly(3,3‴-didodecylquaterthiophene) (PQT-12) and [6,6]-phenyl C61 butyric acid methyl ester have been fabricated and characterized. By varying the polymer loading in the blend, an optimal power conversion efficiency (PCE) of 0.70% has been achieved for a blend consisting of 15 wt % PQT-12, which is an order of magnitude higher than the PCE for a 50 wt % blend. The apparent reason for the large difference is the fact that blends with higher PQT-12 loading are transport limited, with much larger hole-to-electron mobility ratios.
Methane-water clusters under pressure: Are clathrate cages optimal clusters?
Authors: Hartke Bernd
Published: January 2009

Global cluster structure optimization is applied to CH4(H2O)n, n=4–21, in a simple model but with the additional application of external pressure. The combined effect of pressure and of the presence of a methane molecule leads to a structural transition away from the well-known pure water cluster structures. The exact location of this transition is a function of pressure and of cluster size, but it invariably leads to “nestlike” structures as high-pressure form. Clathratelike cages around the methane molecule in the cluster center are less favorable than the best nests for all sizes and at all pressures studied, but they do become low-energy local minima at high pressures.
Structural changes of water in a hydrogel during dehydration
Authors: Sekine Yurina , Ikeda-Fukazawa Tomoko
Published: January 2009

Raman spectra of poly-N,N,-dimethylacrylamide hydrogel were measured in order to investigate the mechanism of the structural changes in water and the polymer network during dehydration. The results show that the vibrational energies of the CO and the O–H stretching modes increase with the extent of dehydration, whereas that of the CH3 rocking mode decreases. The energy shifts observed in the CO stretching and CH3 rocking modes indicate that the polymer network shrinks with the dehydration and undergoes a glass transition at some point. The energy shifts of the OH stretching modes are attributed to changes in the water structure with the structural change of the polymer network. By applying a structural model of bulk water to the spectra of the OH stretching region, the local water structures in the gel and the dried glassy polymer were analyzed. The result shows that a tetragonal water structure consisting of four hydrogen bonds increases in the residual water of the dried glassy polymer, suggesting that the residual water forms a two-dimensional hydrogen-bonded network. The local water structure in a polymer might have important implications for the interpretation of properties of localized water, for instance, water in a mineral crack.
Calculus with a quaternionic variable
Authors: Schwartz Charles
Published: January 2009

Most of theoretical physics is based on the mathematics of functions of a real or a complex variable; yet we frequently are drawn in trying to extend our reach to include quaternions. The noncommutativity of the quaternion algebra poses obstacles for the usual manipulations of calculus, but we show in this paper how many of those obstacles can be overcome. The surprising result is that the first order term in the expansion of F(x+δ) is a compact formula involving both F′(x) and [F(x)−F(x∗)]/(x−x∗). This advance in the differential calculus for quaternionic variables also leads us to some progress in studying integration.
Measurement of femtosecond electron pulse length and the temporal broadening due to space charge
Authors: Wang Xuan , Nie Shouhua , Park Hyuk , Li Junjie , Clinite Rick , Li Renkai , Wang Xijie , Cao Jianming
Published: January 2009

The temporal width of ultrashort electron pulses as a function of beam intensity was measured on the femtosecond time scale with a customized streak camera. The results show that the temporal profile of an electron pulse is Gaussian at low beam intensity and progressively evolves to a top-hat shape due to space charge broadening as the beam intensity increases. The strong correlation between the pulse width and beam intensity observed in our streaking measurements agrees very well with the mean-field calculation and supports the main conclusion of previous theoretical studies that the space charge broadening plays a determinant role.
The impact of nearest neighbor interaction on the resonances in terahertz metamaterials
Authors: Singh Ranjan , Rockstuhl Carsten , Lederer Falk , Zhang Weili
Published: January 2009

By using terahertz time-domain spectroscopy and rigorous simulations, we investigate the impact of gap orientation of neighboring split rings on the three lowest order eigenmodes for a metamaterial based on split ring resonators. We distinct scenarios where neighboring split rings have their gap either on the same or on opposite sides. The two lowest order eigenmodes are marginally affected, whereas the higher order eigenmode experiences a significant spectral reshaping. By modifying the period it is shown that due to a coherent interaction a huge resonance sharpening is observed. Hence potential application can be anticipated by using such materials, e.g., in sensing devices.
Transport properties of AlGaAs/GaAs parabolic quantum wells
Authors: Gao K. H. , Yu G. , Zhou Y. M. , Zhou W. Z. , Lin T. , Chu J. H. , Dai N. , SpringThorpe A. J. , Austing D. G.
Published: January 2009

We report on the magnetotransport properties of 100 nm wide parabolic quantum wells and observe an enhancement of the Hall resistance in one sample but not the other. This phenomenon is likely related to the effective thickness of the electronic slab. We also observe a parabolic negative magnetoresistance originating from electron-electron interactions when only one subband is occupied in one of the samples. The interaction correction to the Drude conductivity is extracted using two methods. We find that the extracted interaction correction increases with increasing tilted angle, for which two possible explanations are given.
Paradoxical phenomena between the homogeneous and inhomogeneous deformations of metallic glasses
Authors: Park Kyoung-Won , Lee Chang-Myeon , Lee Mi-Rim , Fleury Eric , Falk Michael L. , Lee Jae-Chul
Published: January 2009

Experiments in binary alloys demonstrate that metallic glasses exhibiting more plastic strain during homogeneous deformation tend to show lower global plasticity during inhomogeneous deformation. Testing of Cu–Zr binary alloys supports the hypothesis that the formation energy of a shear transformation zone, as extracted from the experimental data, is related to the homogeneous flow rate. We also report the microstructural aspects that control the global plasticity of metallic glasses in the light of structural disordering, softening, and shear localization.
Valve-based flow focusing for drop formation
Authors: Abate Adam R. , Romanowsky Mark B. , Agresti Jeremy J. , Weitz David A.
Published: January 2009

Microfluidic devices can produce highly monodisperse drops at kilohertz rates using flow-focus drop formation. We use single-layer membrane valves to control, in real time, the dimensions of the flow-focus drop makers. This allows drop size and frequency to be controlled in real time and without adjusting flow rates.
Ferroelectric tunable balanced right- and left-handed transmission lines
Authors: Marteau Aurélien , Velu Gabriel , Houzet Gregory , Burgnies Ludovic , Lheurette Eric , Carru Jean Claude , Lippens Didier
Published: January 2009

The tuning of the dispersion characteristics of a balanced composite right- and left-handed transmission lines is demonstrated at centimeter and millimeter wavelengths. To this aim, coplanar waveguides, periodically loaded by interdigitated capacitances and stublike inductances, were fabricated onto a Ba0.5Sr0.5TiO3 ferroelectric thin film. The scattering parameter measurements show that the lines are left handed from 8 to 18 GHz and right handed above. The results are interpreted by the retrieval of the effective permittivity and permeability, which exhibit Drude-like dispersion characteristics with a magnetic plasma frequency, which can be tuned via the voltage-controlled permittivity variation in the BST thin film.
Fabrication of three-dimensional terahertz photonic crystals with diamond structure by particle manipulation assembly
Authors: Takagi Kenta , Kawasaki Akira
Published: January 2009

We reported the fabrication of terahertz photonic crystals by three-dimensional (3D) particle manipulation assembly. Our method, which is based on pick-and-place manipulation and interparticle laser welding, enabled accurate assembling of an arbitrary 3D structure, regardless of particle polydispersity. By using this method, we fabricated a diamond crystal from ZrO2/polyethylene composite particles (diameter of 400 μm). The obtained crystal exhibited a photonic stop gap in the ⟨111⟩ direction; this result was in good agreement with the theoretical result, suggesting that the crystal has a full photonic bandgap at around 0.2 THz.
X-ray photoelectron spectroscopy measurement of n-ZnO/p-NiO heterostructure valence-band offset
Authors: Deng R. , Yao B. , Li Y. F. , Zhao Y. M. , Li B. H. , Shan C. X. , Zhang Z. Z. , Zhao D. X. , Zhang J. Y. , Shen D. Z. , Fan X. W.
Published: January 2009

Valence-band offset (VBO) of n-ZnO/p-NiO heterojunction has been investigated by x-ray photoelectron spectroscopy. Core levels of Zn 2p and Ni 2p were used to align the VBO of n-ZnO/p-NiO heterojunction. It was found that n-ZnO/p-NiO heterojunction has a type-II band alignment and its VBO is determined to be 2.60±0.20 eV, and conduction-band offset is deduced to be 2.93±0.20 eV. The experimental VBO value is in good agreement with the calculated value based on the electron affinity of ZnO and NiO.
Prediction of a Rift Valley fever outbreak
Authors: Anyamba Assaf , Chretien Jean-Paul , Small Jennifer , Tucker Compton J. , Formenty Pierre B. , Richardson Jason H. , Britch Seth C. , Schnabel David C. , Erickson Ralph L. , Linthicum Kenneth J.
Published: January 2009

El Niño/Southern Oscillation related climate anomalies were analyzed by using a combination of satellite measurements of elevated sea-surface temperatures and subsequent elevated rainfall and satellite-derived normalized difference vegetation index data. A Rift Valley fever (RVF) risk mapping model using these climate data predicted areas where outbreaks of RVF in humans and animals were expected and occurred in the Horn of Africa from December 2006 to May 2007. The predictions were subsequently confirmed by entomological and epidemiological field investigations of virus activity in the areas identified as at risk. Accurate spatial and temporal predictions of disease activity, as it occurred first in southern Somalia and then through much of Kenya before affecting northern Tanzania, provided a 2 to 6 week period of warning for the Horn of Africa that facilitated disease outbreak response and mitigation activities. To our knowledge, this is the first prospective prediction of a RVF outbreak.
A zipper network model of the failure mechanics of extracellular matrices
Authors: Ritter Michael C. , Jesudason Rajiv , Majumdar Arnab , Stamenović Dimitrije , Buczek-Thomas Jo Ann , Stone Phillip J. , Nugent Matthew A. , Suki Béla
Published: January 2009

Mechanical failure of soft tissues is characteristic of life-threatening diseases, including capillary stress failure, pulmonary emphysema, and vessel wall aneurysms. Failure occurs when mechanical forces are sufficiently high to rupture the enzymatically weakened extracellular matrix (ECM). Elastin, an important structural ECM protein, is known to stretch beyond 200% strain before failing. However, ECM constructs and native vessel walls composed primarily of elastin and proteoglycans (PGs) have been found to fail at much lower strains. In this study, we hypothesized that PGs significantly contribute to tissue failure. To test this, we developed a zipper network model (ZNM), in which springs representing elastin are organized into long wavy fibers in a zipper-like formation and placed within a network of springs mimicking PGs. Elastin and PG springs possessed distinct mechanical and failure properties. Simulations using the ZNM showed that the failure of PGs alone reduces the global failure strain of the ECM well below that of elastin, and hence, digestion of elastin does not influence the failure strain. Network analysis suggested that whereas PGs drive the failure process and define the failure strain, elastin determines the peak and failure stresses. Predictions of the ZNM were experimentally confirmed by measuring the failure properties of engineered elastin-rich ECM constructs before and after digestion with trypsin, which cleaves the core protein of PGs without affecting elastin. This study reveals a role for PGs in the failure properties of engineered and native ECM with implications for the design of engineered tissues.
TRPA1 acts as a cold sensor in vitro and in vivo
Authors: Karashima Yuji , Talavera Karel , Everaerts Wouter , Janssens Annelies , Kwan Kelvin Y. , Vennekens Rudi , Nilius Bernd , Voets Thomas
Published: January 2009

TRPA1 functions as an excitatory ionotropic receptor in sensory neurons. It was originally described as a noxious cold-activated channel, but its cold sensitivity has been disputed in later studies, and the contribution of TRPA1 to thermosensing is currently a matter of strong debate. Here, we provide several lines of evidence to establish that TRPA1 acts as a cold sensor in vitro and in vivo. First, we demonstrate that heterologously expressed TRPA1 is activated by cold in a Ca2+-independent and Ca2+store-independent manner; temperature-dependent gating of TRPA1 is mechanistically analogous to that of other temperature-sensitive TRP channels, and it is preserved after treatment with the TRPA1 agonist mustard oil. Second, we identify and characterize a specific subset of cold-sensitive trigeminal ganglion neurons that is absent in TRPA1-deficient mice. Finally, cold plate and tail-flick experiments reveal TRPA1-dependent, cold-induced nociceptive behavior in mice. We conclude that TRPA1 acts as a major sensor for noxious cold.
Regulation of ribonuclease E activity by the L4 ribosomal protein of
Escherichia coli
Authors: Singh Dharam , Chang Ssu-Jean , Lin Pei-Hsun , Averina Olga V. , Kaberdin Vladimir R. , Lin-Chao Sue
Published: January 2009

Whereas ribosomal proteins (r-proteins) are known primarily as components of the translational machinery, certain of these r-proteins have been found to also have extraribosomal functions. Here we report the novel ability of an r-protein, L4, to regulate RNA degradation in
Escherichia coli
. We show by affinity purification, immunoprecipitation analysis, and
E. coli
two-hybrid screening that L4 interacts with a site outside of the catalytic domain of RNase E to regulate the endoribonucleolytic functions of the enzyme, thus inhibiting RNase E-specific cleavage in vitro, stabilizing mRNAs targeted by RNase E in vivo, and controlling plasmid DNA replication by stabilizing an antisense regulatory RNA normally attacked by RNase E. Broader effects of the L4-RNase E interaction on
E. coli
transcripts were shown by DNA microarray analysis, which revealed changes in the abundance of 65 mRNAs encoding the stress response proteins HslO, Lon, CstA, YjiY, and YaeL, as well as proteins involved in carbohydrate and amino acid metabolism and transport, transcription/translation, and DNA/RNA synthesis. Analysis of mRNA stability showed that the half lives of stress-responsive transcripts were increased by ectopic expression of L4, which normally increases along with other r-proteins in
E. coli
under stress conditions, and also by inactivation of RNase E. Our finding that L4 can inhibit RNase E-dependent decay may account at least in part for the elevated production of stress-induced proteins during bacterial adaptation to adverse environments.
Intermittent hypoxia degrades HIF-2α via calpains resulting in oxidative stress: Implications for recurrent apnea-induced morbidities
Authors: Nanduri Jayasri , Wang Ning , Yuan Guoxiang , Khan Shakil A. , Souvannakitti Dangjai , Peng Ying-Jie , Kumar Ganesh K. , Garcia Joseph A. , Prabhakar Nanduri R.
Published: January 2009

Intermittent hypoxia (IH) occurs in many pathological conditions including recurrent apneas. Hypoxia-inducible factors (HIFs) 1 and 2 mediate transcriptional responses to low O
2
. A previous study showed that HIF-1 mediates some of the IH-evoked physiological responses. Because HIF-2α is an orthologue of HIF-1α, we examined the effects of IH on HIF-2α, the O
2
-regulated subunit expression, in pheochromocytoma 12 cell cultures. In contrast to the up-regulation of HIF-1α, HIF-2α was down-regulated by IH. Similar down-regulation of HIF-2α was also seen in carotid bodies and adrenal medullae from IH-exposed rats. Inhibitors of calpain proteases (ALLM, ALLN) prevented IH-evoked degradation of HIF-2α whereas inhibitors of prolyl hydroxylases or proteosome were ineffective. IH activated calpain proteases and down-regulated the endogenous calpain inhibitor calpastatin. IH-evoked HIF-2α degradation led to inhibition of SOD2 transcription, resulting in oxidative stress. Over-expression of transcriptionally active HIF-2α prevented IH-evoked oxidative stress and restored SOD2 activity. Systemic treatment of IH-exposed rats with ALLM rescued HIF-2α degradation and restored SOD2 activity, thereby preventing oxidative stress and hypertension. These observations demonstrate that, unlike continuous hypoxia, IH leads to down-regulation of HIF-2α via a calpain-dependent signaling pathway and results in oxidative stress as well as autonomic morbidities.
Molecular dynamics calculations suggest a conduction mechanism for the M2 proton channel from influenza A virus
Authors: Khurana Ekta , Peraro Matteo Dal , DeVane Russell , Vemparala Satyavani , DeGrado William F. , Klein Michael L.
Published: January 2009

The M2 protein of the influenza A virus is activated by low endosomal pH and performs the essential function of proton transfer into the viral interior. The resulting decrease in pH within the virion is essential for the uncoating and further replication of the viral genetic material. The x-ray crystal [Stouffer AL,
et al.
(2008) Nature 451:596–599] and solution NMR [Schnell JR, Chou JJ (2008) Nature 451:591–595] structures of the transmembrane region of the M2 homo-tetrameric bundle both revealed pores with narrow constrictions at one end, leaving a question as to how protons enter the channel. His-37, which is essential for proton-gating and selective conduction of protons, lies in the pore of the crystallographic and NMR structures. Here, we explore the different protonation states of the His-37 residues of the M2 bundle in a bilayer using molecular dynamics (MD) simulations. When the His-37 residues are neutral, the protein prefers an Open
out
-Closed
in
conformation in which the channel is open to the environment on the outside of the virus but closed to the interior environment of the virus. Diffusion of protons into the channel from the outside of the virus and protonation of His-37 residues in the tetramer stabilizes an oppositely gated Closed
out
-Open
in
conformation. Thus, protons might be conducted through a transporter-like mechanism, in which the protein alternates between Open
out
-Closed
in
and Closed
out
-Open
in
conformations, and His-37 is protonated/deprotonated during each turnover. The transporter-like mechanism is consistent with the known properties of the M2 bundle, including its relatively low rate of proton flux and its strong rectifying behavior.
“Beautiful Minds”: A Seminar Course on the Psychology of Genius
Authors: Simpson Kevin E.
Published: January 2009

Genius-level achievement is a natural draw for undergraduate students, both as a cultural phenomenon and as a topic domain within the science of psychology. Yet within the teaching of psychology literature, the psychology of genius has been largely ignored. I designed a course that combines primary source material drawn from existing empirical findings in the genius and creativity literature with a novel method of inquiry for undergraduates, psychobiography. As an intellectually provocative area of study, the psychology of genius offers teachers a unique way to teach about theory and research in contemporary psychology through a case-based approach. This article describes course readings and assignments, topical areas of discussion, evidence of student learning, and student perceptions of knowledge gains.
Scholarship in Teaching and Learning: An Interview with John Mitterer
Authors: Daniel David B.
Published: January 2009

John Mitterer earned his PhD in cognitive psychology from McMaster University. Like many teaching professors, his career took an unexpected turn early on when he was hired to teach introductory psychology at Brock University, near Niagara Falls, in Ontario, Canada. It was love at first lecture. He never left the course and now, as a full professor some 25 years later, has taught well over 20,000 students. Along the way he has participated in the development of a wide variety of learning materials, including textbooks, videodiscs of support materials, student-learning CD-ROMs, online learning objects, Web sites, test banks, PowerPoint slides, study guides, and instructor's manuals. Mitterer now thinks of himself as a scholar of teaching and learning with a special interest in the educational potential of digital technology. He is a frequent presenter at conferences devoted to teaching and learning and currently holds a Brock University Chancellor's Chair for Teaching Excellence. He is the recipient of the 2003 Brock University Distinguished Teaching Award, a 2003 Ontario Confederation of University Faculty Associations (OCUFA) Teaching Award, a 2004 3M Teaching Fellowship, and the 2005 Canadian Psychological Association Award for Distinguished Contributions to Education and Training in Psychology.

David B. Daniel is involved with forging reciprocal links between cognitive-developmental psychology and teaching practices and pedagogy. He is the coordinator of the Society for Research in Child Development's (SRCD) Teaching of Developmental Science Institute as well as chair of the SRCD Teaching Committee, and the managing editor of Mind, Brain, and Education. He chaired the Society for the Teaching of Psychology's task force on pedagogical innovations. His interest in the development of effective teaching has informed his current efforts to develop effective pedagogical techniques that positively impact both student learning and teacher performance.
Development of the Fund for Excellence in the Teaching of Psychology
Authors: Korn James H.
Published: January 2009

I review the development of the Fund for Excellence, which provides financial support for the Society for the Teaching of Psychology teaching awards. James McConnell provided funds in the early years of the awards before the Fund was established in 1987. I review the growth of the Fund and its administration by a Board of Directors, then make suggestions for future directions.
Reading and spelling in children with severe speech and physical impairments: a comparative study
Authors: Smith Martine , Sandberg Annika Dahlgren , Larsson Maria
Published: January 2009

Background: Effective literacy skills are crucial in supporting communication for children with severe speech and physical impairments (SSPI). Reading and spelling difficulties are reported to be over‐represented in this group, even where language and cognitive skills are age appropriate.

Aims: To compare the performance of children with SSPI on a range of language, reading and spelling tasks with that of their typically developing peers matched for receptive vocabulary and mental age.

Methods & Procedures: A wide range of tasks was developed as part of a larger study exploring phonological awareness, reading and spelling skills. All tasks were accessible to children with severe physical impairments. Two groups of primary school‐aged children were recruited, children with SSPI of average intelligence, and naturally speaking peers, matched for receptive vocabulary. Children were assessed individually on language, non‐verbal cognition, phonological awareness, reading and spelling tasks.

Outcomes & Results: Sixteen children with SSPI were recruited. Their performance was compared with that of 15 naturally speaking peers, matched for receptive vocabulary scores. The children with SSPI achieved significantly lower scores on reading and spelling measures relative to their naturally speaking peers. However, at least one participant with SSPI scored at ceiling on each task, indicating that SSPI do not preclude the development of reading and spelling, at least in the early stages of literacy development.

Conclusions & Implications: This study indicates that some children with severe speech impairments can develop phonological awareness, reading and spelling skills. However, the data suggest that phonological awareness may not be as good a predictor of reading and spelling abilities in this group of children as in typically developing children. Further research is needed to track development of reading and spelling, as well as the instructional support needed to scaffold more effective skills in these areas.
Home literacy environment: characteristics of children with cerebral palsy
Authors: Peeters Marieke , Verhoeven Ludo , van Balkom Hans , de Moor Jan
Published: January 2009

Background: Various aspects of the home literacy environment are considered to stimulate the emergent literacy development in children without disabilities. It is important to gain insight into the home literacy environment of children with cerebral palsy given that they have been shown to have difficulty acquiring literacy skills.

Aims: The aims of the present study were to investigate whether the home literacy environment of children with cerebral palsy was comparable with that of peers without disabilities and to investigate to what extent speech, fine motor, and intellectual impairments limit their home literacy experiences.

Methods & Procedures: Questionnaires addressed to the parents of the children were devised to investigate differences in the home literacy environment in 40 children with cerebral palsy and in 62 peers without disabilities who were comparable on chronological age, i.e., 6 years old, socio‐economic status (SES) and sex. The relative influence of speech intelligibility, fine motor skills, and intelligence skills for the home literacy environment factors of children with cerebral palsy was investigated.

Outcomes & Results: Only a few group differences were significant: children with cerebral palsy were less interested in participating in writing activities, and less involved in word‐orientation activities during shared storybook reading. On the other hand, parents of children with cerebral palsy were doing more leisure activities with their child. The speech intelligibility scores of the children with cerebral palsy predicted the amount of emergent literacy activities they were doing with their parents, as wells as their active participation in word‐related activities during storybook reading. In addition, the active participation of the child in story‐related activities could be predicted by his or her fine motor skills. Furthermore, parents of the children in the comparison group often had high expectations, while parents of the children with cerebral palsy often did not know what expectations to have for their child's literacy level at the end of elementary school.

Conclusions & Implications: Although both groups have stimulating home literacy environments, children with cerebral palsy with speech or fine motor impairments are disadvantaged in a small number of literacy activities. Teachers and speech and language therapists can work with parents to give them suggestions on how to conduct emergent literacy activities with their child with speech impairments as well as how on to involve their child with speech and fine motor dysfunctions more actively in storybook reading activities. Furthermore, parents should be given more information about their child's language development in order the better to understand what goals are achievable so they may begin to form realistic expectations.
Working-memory capacity predicts the executive control of visual search among distractors: The influences of sustained and selective attention
Authors: Poole Bradley J. , Kane Michael J.
Published: January 2009

Variation in working-memory capacity (WMC) predicts individual differences in only some attention-control capabilities. Whereas higher WMC subjects outperform lower WMC subjects in tasks requiring the restraint of prepotent but inappropriate responses, and the constraint of attentional focus to target stimuli against distractors, they do not differ in prototypical visual-search tasks, even those that yield steep search slopes and engender top-down control. The present three experiments tested whether WMC, as measured by complex memory span tasks, would predict search latencies when the 1–8 target locations to be searched appeared alone, versus appearing among distractor locations to be ignored, with the latter requiring selective attentional focus. Subjects viewed target-location cues and then fixated on those locations over either long (1,500–1,550 ms) or short (300 ms) delays. Higher WMC subjects identified targets faster than did lower WMC subjects only in the presence of distractors and only over long fixation delays. WMC thus appears to affect subjects’ ability to maintain a constrained attentional focus over time.
Short article: No evidence for a cue mismatch in negative priming
Authors: Mayr Susanne , Hauke Robert , Buchner Axel , Niedeggen Michael
Published: January 2009

An experiment is reported in which the cue mismatch hypothesis of negative priming, an important novel variant of the mismatching hypothesis, was tested. A cue mismatch and a no mismatch condition were contrasted in a visual discrimination task. In the prime display of cue mismatch ignored-repetition trials, the colour of the prime distractor was different from the colour of the cue indicating the selection feature (coloured square). In probe displays, cue and repeated stimulus had the same colour. In the no mismatch condition, the visual cue was neutral in terms of colour (always black), so that there was always no cue mismatch between prime and probe displays. Contrary to the prediction of the cue mismatch hypothesis, the negative priming effect was not larger in the cue mismatch than in the no mismatch condition. The cue mismatch hypothesis must therefore be rejected. In contrast, the episodic retrieval account is consistent with the results.
Short article: Social gaze cueing to auditory locations
Authors: Newport R. , Howarth S.
Published: January 2009

Spatial attention is oriented by social visual cues: targets appearing at cued (gazed-at) locations are detected more rapidly than those appearing at uncued locations. The current studies provide evidence that social gaze directs attention to auditory as well as visual targets at cued locations. For auditory target detection the effect lasted from 300 to 1,005 ms while for discrimination the effect was restricted to 600 ms. Improved performance at 600-ms stimulus onset asynchrony was observed across all experiments and may reflect an optimal processing window for social stimuli. In addition, the orienting of attention by gaze was impaired by the presentation of negative faces. These experiments further demonstrate the unique and cross-modal nature of social gaze cueing.
Training with anxiety has a positive effect on expert perceptual–motor performance under pressure
Authors: Oudejans Raôul R. D. , Pijpers J. Rob
Published: January 2009

In two experiments, we examined whether training with anxiety can prevent choking in experts performing perceptual–motor tasks. In Experiment 1, 17 expert basketball players practised free throws over a 5-week period with or without induced anxiety. Only after training with anxiety did performance no longer deteriorate during the anxiety posttest. In Experiment 2, 17 expert dart players practised dart throwing from a position high or low on a climbing wall, thus with or without anxiety. Again, only after training with anxiety was performance maintained during the anxiety posttest, despite higher levels of anxiety, heart rate, and perceived effort. It is concluded that practising under anxiety can prevent choking in expert perceptual–motor performance, as one acclimatizes to the specific processes accompanying anxiety.
Short Article: Tracking the Transition from Sublexical to Lexical Processing: On the Creation of Orthographic and Phonological Lexical Representations
Authors: Maloney Erin , Risko Evan F. , O'Malley Shannon , Besner Derek
Published: January 2009

Participants read aloud nonword letter strings, one at a time, which varied in the number of letters. The standard result is observed in two experiments; the time to begin reading aloud increases as letter length increases. This result is standardly understood as reflecting the operation of a serial, left-to-right translation of graphemes into phonemes. The novel result is that the effect of letter length is statistically eliminated by a small number of repetitions. This elimination suggests that these nonwords are no longer always being read aloud via a serial left-to-right sublexical process. Instead, the data are taken as evidence that new orthographic and phonological lexical entries have been created for these nonwords and are now read at least sometimes by recourse to the lexical route. Experiment 2 replicates the interaction between nonword letter length and repetition observed in Experiment 1 and also demonstrates that this interaction is not seen when participants merely classify the string as appearing in upper or lower case. Implications for existing dual-route models of reading aloud and Share's self-teaching hypothesis are discussed.
Short article: Is luck on my side? Optimism, pessimism, and ambiguity aversion
Authors: Pulford Briony D.
Published: January 2009

The influences of optimism and pessimism on ambiguity aversion were investigated in two tasks that manipulated the presence or absence of a potentially competitive experimenter. A total of 112 participants chose which option—ambiguous or known-risk—they preferred in the two slightly differing Ellsberg urns tasks. Optimism was measured using the Extended Life Orientation Test (ELOT). Highly optimistic people showed significantly less ambiguity aversion than less optimistic people when information was given that the number of balls was randomly determined. This pattern was present but less pronounced in the condition when the composition of the ambiguous urn could be interpreted as being influenced (rigged) by the experimenter. Pessimism was uninfluential. Perceptions of the situation, especially the degree of trust in the experimenter, were significantly influenced by the participants’ optimism. People who do not have highly optimistic personalities tend to shy away from choosing ambiguous options. When ambiguity is clear, and trust issues are removed, people's optimistic outlook influences their degree of ambiguity aversion and thus their decisions.
Short article: Does conspicuity enhance distraction? Saliency and eye landing position when searching for objects
Authors: Foulsham Tom , Underwood Geoffrey
Published: January 2009

While visual saliency may sometimes capture attention, the guidance of eye movements in search is often dominated by knowledge of the target. How is the search for an object influenced by the saliency of an adjacent distractor? Participants searched for a target amongst an array of objects, with distractor saliency having an effect on response time and on the speed at which targets were found. Saliency did not predict the order in which objects in target-absent trials were fixated. The within-target landing position was distributed around a modal position close to the centre of the object. Saliency did not affect this position, the latency of the initial saccade, or the likelihood of the distractor being fixated, suggesting that saliency affects the allocation of covert attention and not just eye movements.
Short article: Active involvement, not illusory control, increases risk taking in a gambling game
Authors: Martinez Frédéric , Bonnefon Jean-François , Hoskens Julie
Published: January 2009

The research considers the influence of choice (the possibility for the player to choose a gamble or another) and involvement (the physical interaction with the gambling device) on risk taking in gambling games and whether this influence is mediated by illusory control over the outcome of the gamble. Results of a laboratory experiment ( n = 100) show that (a) although choice does increase illusory control, this influence does not translate in increased risk taking, and (b) whilst involvement does increase risk taking, this effect is not mediated by illusory control. These results are discussed in relation to problem gambling, beliefs in the deployability of personal luck, and arousal approaches to risk taking.
Short article: Dimension-based working memory-driven capture of visual selection
Authors: Pan Yi , Xu Baihua , Soto David
Published: January 2009

We studied attentional capture by dimensional cueing of visual objects. Participants received two dimension cues, one relevant for a memory test and the other relevant for an attention test. Performance in the attention task was impaired on incongruent trials (i.e., when the relevant dimensions for memory and attention did not match) relative to congruent trials. Dimensional cueing effects were enhanced when the cued dimension was held “online” in working memory through the trial, compared to when the cued dimension did not have to be held in memory. The findings demonstrate that dimensional cueing of visual selection can occur in a largely automatic manner, with working memory exerting a strong modulatory influence. We discuss the implications of these findings for understanding the interaction between memory and attention.
Short article: Language comprehenders retain implied shape and orientation of objects
Authors: Pecher Diane , van Dantzig Saskia , Zwaan Rolf A. , Zeelenberg René
Published: January 2009

According to theories of embodied cognition, language comprehenders simulate sensorimotor experiences to represent the meaning of what they read. Previous studies have shown that picture recognition is better if the object in the picture matches the orientation or shape implied by a preceding sentence. In order to test whether strategic imagery may explain previous findings, language comprehenders first read a list of sentences in which objects were mentioned. Only once the complete list had been read was recognition memory tested with pictures. Recognition performance was better if the orientation or shape of the object matched that implied by the sentence, both immediately after reading the complete list of sentences and after a 45-min delay. These results suggest that previously found match effects were not due to strategic imagery and show that details of sensorimotor simulations are retained over longer periods.