bluuebunny/crossref_metadata_2025 huggingface dataset:
An orbital-invariant and strictly size extensive post-Hartree-Fock correlation functional
Authors: Kollmar Christian , Neese Frank
Published: August 2011

A strictly size extensive post-Hartree-Fock correlation functional being invariant with respect to orbital transformations within the occupied and virtual subspaces is presented. While avoiding the necessity to solve additional Z vector equations for the calculation of properties and energy gradients, this functional reproduces almost exactly the results of coupled-cluster singles doubles (CCSD) calculations. In particular, it is demonstrated that the method is rigorous in the sense that it can be systematically improved by the perturbative inclusion of triple excitations in the same way as CCSD. As to the computational cost, the presented approach is somewhat more expensive than the CCSD if the energy is variationally optimized with respect to both the orbitals and the excitation amplitudes. Replacement of orbital optimization by the Brueckner condition reduces the computational cost by a factor of two, thus making the method less expensive than CCSD.
Extrinsic origin of room-temperature ferromagnetism in Co-doped ZnO annealed in Zn vapor
Authors: Yan Guoqing , Xuan Haicheng
Published: August 2011

Co-doped ZnO and CoO were prepared at 950 °C by the solid-state reaction method, then were annealed in N2 flow at 950 °C, and finally annealed in Zn vapor at 600 °C or 800 °C. The samples before annealing in Zn vapor have no ferromagnetism, but after annealing in Zn vapor, Co-doped ZnO and CoO both exhibit room-temperature ferromagnetism. Through x-ray diffraction and element composition measurements, it was found that the ferromagnetism of Co-doped ZnO annealed in Zn vapor is extrinsic and comes from cubic Co5Zn21 and/or cubic CoZn.
A Thomson parabola ion imaging spectrometer designed to probe relativistic intensity ionization dynamics of nanoclusters
Authors: Rajeev R. , Rishad K. P. M. , Trivikram T. Madhu , Narayanan V. , Krishnamurthy M.
Published: August 2011

Conventional techniques of probing ionization dynamics at relativistic intensities for extended target systems such as clusters are difficult both due to problems of achieving good charge resolution and signal integration over the focal volume. Simultaneous measurement of arrival time, necessary for these systems, has normally involved complicated methods. We designed and developed a Thomson parabola imaging spectrometer that overcomes these problems. Intensity sampling method evolved in this report is proved to be mandatory for probing ionization dynamics of clusters at relativistic intensities. We use this method to measure charge resolved kinetic energy spectra of argon nanoclusters at intensities of 4 × 1018 W cm−2.
Interface controlled photovoltaic effect in epitaxial Pb(Zr,Ti)O3 films with tetragonal structure
Authors: Pintilie L. , Dragoi C. , Pintilie I.
Published: August 2011

It is shown that the short-circuit photocurrent measured under illumination in Pb(Zr,Ti)O3 epitaxial films is strongly dependent on the metal used as the top electrode. The magnitude of the photocurrent varies by more than 2 orders of magnitude from Pt (largest signal) to Al (smallest signal). The differences are for both directions of polarization. The imprint is also dependent on the top metal electrode, with a direct effect on the shape of the spectral distribution. The results support the hypothesis that the origin of the photovoltaic effect in ferroelectric thin films is different from that of the anomalous photovoltaic effect observed in bulk ceramics and single crystals.
Colloidal interactions mediated by end-adsorbing polymer-like micelles
Authors: Helgeson Matthew E. , Wagner Norman J.
Published: August 2011

We derive a statistical mechanical model for colloidal interactions mediated by polymer-like micelles (PLMs) that adsorb at the colloid surface. The model considers the end-adsorption and reversible scission of ideal chains, and is based on experimentally measurable parameters relevant to PLMs. The model predicts interparticle attractions due to micellar bridging that are stronger and longer-range than those encountered in ordinary telechelic polymers. Mapping the analytical potential onto the more familiar Double Yukawa potential allows, for the first time, accurate, a priori prediction of suspension microstructure and phase behavior when compared to experimental data for model nanoparticles dispersed in wormlike micelles over a range of solution conditions.
Electron acceleration by laser wakefield and x-ray emission at moderate intensity and density in long plasmas
Authors: Ferrari H. E. , Lifschitz A. F. , Maynard G. , Cros B.
Published: August 2011

The dynamics of electron acceleration by laser wakefield and the associated x-rays emission in long plasmas are numerically investigated for parameters close to the threshold of laser self-focusing. The plasma length is set by the use of dielectric capillary tubes that confine the gas and the laser energy. Electrons self-injection and acceleration to the 170 MeVs are obtained for densities as low as 5 × 1018 cm−3 and a moderate input intensity (0.77 × 1018 W/cm2). The associated x-ray emission at the exit of the capillary tube is shown to be an accurate diagnostic of the electrons self-injection and acceleration process.
Analysis on switching mechanism of graphene oxide resistive memory device
Authors: Ki Hong Seul , Eun Kim Ji , Kim Sang Ouk , Jin Cho Byung
Published: August 2011

Recently, a flexible resistive switching memory device using graphene oxide was successfully demonstrated. In this work, the new findings on the switching mechanism of the graphene oxide memory are presented through a comprehensive study on the switching phenomena. It has been found that the switching operation of graphene oxide resistive switching memory (RRAM) is governed by dual mechanism of oxygen migration and Al diffusion. However, the Al diffusion into the graphene oxide is the main factor to determine the switching endurance property which limits the long term lifetime of the device. The electrode dependence on graphene oxide RRAM operation has been analyzed as well and is attributed to the difference in surface roughness of graphene oxide for the different bottom electrodes.
Numerical simulation of anomaleous electrons generation in a vacuum diode
Authors: Levko D. , Gurovich V. Tz. , Krasik Ya. E.
Published: August 2011

The results of numerical simulations of electron beam generation in a vacuum coaxial diode where the electron emission is governed first by field emission and then by explosive emission are presented. It is shown that the transition from field emission to explosive emission leads to the generation of anomalous fast electrons with energies larger than the applied voltage. The latter occurs due to the acceleration of the field-emitted electrons by the self-electric field of the electrons that are emitted into the cathode-anode gap at the beginning of the explosive emission. It is shown that the energy of anomalous electrons depends on the radius of the cathode, time of the beginning of the explosion emission, and the amplitude of the cathode potential and its rise time.
Giant magnetocaloric effect in antiferromagnetic borocarbide superconductor RNi2B2C (R = Dy, Ho, and Er) compounds
Authors: Li Lingwei , Nishimura Katsuhiko , Kadonaga Michiaki , Qian Zhenghong , Huo Dexuan
Published: August 2011

The magnetocaloric effect (MCE) in antiferromagnetic borocarbide superconductor RNi2B2C (R = Dy, Ho, and Er) compounds have been investigated by measuring the temperature and field dependences of heat capacity. An inverse MCE was observed, which is attributed to the nature of the antiferromagnetic state under low magnetic field and at low temperatures for the present RNi2B2C compounds. A normal giant/large MCE was observed under higher magnetic field change, which is related to a field-induced first-order metamagnetic transition from antiferromagnetic to ferromagnetic state. For a field change of 5 T, the maximum values of magnetic entropy change (− ΔSMmax) reach 17.6, 17.7, and 9.8 J kg−1 K−1 for R = Dy, Ho, and Er, respectively. The corresponding values of maximum adiabatic temperature changes (ΔTadmax) are 9.7, 11, and 4.6 K. The present results indicated the antiferromagnetic borocarbide superconductor RNi2B2C compounds could be promising candidates for low temperature magnetic refrigeration.
BioPhotonics workstation: A versatile setup for simultaneous optical manipulation, heat stress, and intracellular pH measurements of a live yeast cell
Authors: Aabo Thomas , Banás Andrew Raphael , Glückstad Jesper , Siegumfeldt Henrik , Arneborg Nils
Published: August 2011

In this study we have modified the BioPhotonics workstation (BWS), which allows for using long working distance objective for optical trapping, to include traditional epi-fluorescence microscopy, using the trapping objectives. We have also added temperature regulation of sample stage, allowing for fast temperature variations while trapping. Using this modified BWS setup, we investigated the internal pH (pHi) response and membrane integrity of an optically trapped Saccharomyces cerevisiae cell at 5 mW subject to increasing temperatures. The pHi of the cell is obtained from the emission of 5-(and-6)-carboxyfluorescein diacetate, succinimidyl ester, at 435 and 485 nm wavelengths, while the permeability is indicated by the fluorescence of propidium iodide. We present images mapping the pHi and permeability of the cell at different temperatures and with enough spatial resolution to localize these attributes within the cell. The combined capability of optical trapping, fluorescence microscopy and temperature regulation offers a versatile tool for biological research.
An approximate density-functional method using the Harris-Foulkes functional
Authors: Bellchambers G. D. , Manby F. R.
Published: August 2011

We present a method which uses the results of a molecular Kohn-Sham calculation at a reference geometry to approximate the energy at many different geometries. The Kohn-Sham electron density of the reference geometry is decomposed into atomic fragments, which move with the nuclei to approximate the density at a new geometry and the energy is evaluated with the Harris-Foulkes functional. Preliminary results for a biological quantum-mechanics/molecular-mechanics trajectory are promising: the errors of reference-geometry Harris-Foulkes (compared to full self-consistent Kohn-Sham) for the PBE exchange-correlation functional have the same magnitude as the difference between the energies of PBE and BLYP.
Reciprocity in the degeneracies of some tetra-atomic molecular ions
Authors: Bene Erika , Vértesi Tamás , Englman Robert
Published: August 2011

Various ab initio computations, as, e.g., in G. J. Halász and Á. Vibók, Int. J. Quantum Chem. 111, 342 (2011), have shown that in molecules of the type (HCCH)+, when the extremal H atoms are distorted from a linear form but maintain a planar geometry, a pair of conical intersections (ci) occur at such positions that the ratios of the distortional coordinates of the two atoms are in the two ci's reciprocals of each other. These computations have here been extended to locate the ci's also for HCNH. The two groups of results are explained by simple analytic perturbational expressions for the energy differences of the lowest adjacent electronic states, with inclusion of excited state effects.
Pattern formation and nonlinear evolution in alloy surfaces by ion-beam sputtering
Authors: Bharathi M. S. , Ramanarayan H. , Zhang Y. W.
Published: August 2011

Nanoscale pattern formation on surfaces by ion beam sputtering is driven by the competition between the erosion and the diffusion processes. In alloys, these processes are component-dependent. We present a kinetic Monte Carlo model for sputtering of alloy surfaces which exhibits morphological ripples and compositional patterns. The evolution of the ripple amplitude shows a crossover from an early stage exponential growth to a later stage power-law growth. We also present a nonlinear dynamic model which shows both the crossover and the surface patterns, confirming the importance of nonlinear terms in understanding the dynamics of alloy sputtering.
How accurate are the nonlinear chemical Fokker-Planck and chemical Langevin equations?
Authors: Grima Ramon , Thomas Philipp , Straube Arthur V.
Published: August 2011

The chemical Fokker-Planck equation and the corresponding chemical Langevin equation are commonly used approximations of the chemical master equation. These equations are derived from an uncontrolled, second-order truncation of the Kramers-Moyal expansion of the chemical master equation and hence their accuracy remains to be clarified. We use the system-size expansion to show that chemical Fokker-Planck estimates of the mean concentrations and of the variance of the concentration fluctuations about the mean are accurate to order Ω−3/2 for reaction systems which do not obey detailed balance and at least accurate to order Ω−2 for systems obeying detailed balance, where Ω is the characteristic size of the system. Hence, the chemical Fokker-Planck equation turns out to be more accurate than the linear-noise approximation of the chemical master equation (the linear Fokker-Planck equation) which leads to mean concentration estimates accurate to order Ω−1/2 and variance estimates accurate to order Ω−3/2. This higher accuracy is particularly conspicuous for chemical systems realized in small volumes such as biochemical reactions inside cells. A formula is also obtained for the approximate size of the relative errors in the concentration and variance predictions of the chemical Fokker-Planck equation, where the relative error is defined as the difference between the predictions of the chemical Fokker-Planck equation and the master equation divided by the prediction of the master equation. For dimerization and enzyme-catalyzed reactions, the errors are typically less than few percent even when the steady-state is characterized by merely few tens of molecules.
The classical exchange algebra of a Green-Schwarz sigma model on supercoset target space with $\mathbb {Z}_{4m}$Z4m grading
Authors: Ke Sanmin , Yang Wenli , Wang Chun , Jiang Kexia , Shi Kangjie
Published: August 2011

We investigate the classical exchange algebra of the monodromy matrix for a Green-Schwarz sigma model on supercoset target space with $\mathbb {Z}_{4m}$Z4m grading by using a first-order Hamiltonian formulation and by adding to the Lax connection terms proportional to constraints. This enables us to show that the conserved charges of the theory are in involution in the Poisson bracket sense. Our calculation is based on a general world-sheet metric. Taking a particular case of m = 1 (and a particular choice of supergroup), our results coincide with those of the Green-Schwarz superstring theory in AdS5 × S5 background obtained by Magro [J. High Energy Phys. 0901, 021 (2009)]10.1088/1126-6708/2009/01/021.
Chemical structure study of SiO2/4H-SiC (0001) interface transition region by angle-dependent x-ray photoelectron spectroscopy
Authors: Zhu Qiaozhi , Huang Lingqin , Li Wenbo , Li Shenmin , Wang Dejun
Published: August 2011

The chemical structure of SiO2/4H-SiC (0001) interface transition region is investigated using angle-dependent x-ray photoelectron spectroscopy. The relative intensities of various silicon oxycarbides (SiOxCy) components as a function of polar emission angle suggest that SiOC3, SiO2C2, SiO3C, and SiO2 have different depth distributions at the interface. Then a nonabrupt four-layer structure model is proposed. And the relative intensities of various SiOxCy species are fitted based on the model by an electron damping scheme. The well fitted results indicate that the SiO2/4H-SiC (0001) interface transition region can be described by a chemically nonabrupt four-layer structure model well.
Third-order nonlinearity in silicon beyond 2350 nm
Authors: Gholami Faezeh , Zlatanovic Sanja , Simic Aleksandar , Liu Lan , Borlaug David , Alic Nikola , Nezhad Maziar P. , Fainman Yeshaiahu , Radic Stojan
Published: August 2011

Measurement of the Kerr nonlinearity in silicon is reported in the 2350 nm to 2750 nm wavelength range, where three-photon absorption effect is present. The measurements confirm that the Kerr interaction strength is comparable to that in the near-infrared. The measured dispersion trend for the Kerr coefficient is consistent with that obtained using Kramers-Krönig relations. Three-photon absorption was measured, and its effect on the nonlinear figure of merit in silicon appears not to be as restrictive as that of two-photon absorption. The results identify silicon as a promising platform for parametric processes in mid-infrared spectral region.
A spin-valve device based on dumbbell-shaped graphene nanoislands
Authors: Ma Zhaoli , Sheng Weidong
Published: August 2011

Electron transport in a graphene nanoisland with mixed edge profiles is studied by using the spin-unrestricted Hubbard model. The dumbbell-shaped device consists of two hexagonal nanoislands with zigzag edges connected by a armchair nanoribbon. Including the nearest-neighbor hopping and on-site Coulomb repulsion, the self-consistent calculation shows that two distinct ferromagnetic configurations allowed for the proposed device act like ON and OFF states for spin-polarized electrons. Furthermore, the spin-valve effect is demonstrated, as a proof of concept, in the device occupied by one ferromagnetic configuration without resorting to external magnetic or electric fields.
Communication: Uncovering molecule-TiO2 interactions with nonlinear spectroscopy
Authors: Miller Stephen A. , West Brantley A. , Curtis Anna C. , Papanikolas John M. , Moran Andrew M.
Published: August 2011

Femtosecond transient grating experiments are used to investigate electronic structures and transport mechanisms in dye-sensitized nanocrystalline TiO2 films. This study examines two molecular sensitizers spanning the weak (a phosphonated Ruthenium complex) and strong (catechol) molecule-TiO2 coupling regimes. It is shown that strong molecule-TiO2 interactions give rise to photoinduced vibrational coherences at the interface between species. We suggest that the amplitudes of these coherences reflect the molecule-TiO2 coupling strength and signify the delocalization of excited state wavefunctions.
Trophic ecology of two non-native hydrozoan medusae in the upper San Francisco Estuary
Authors: Wintzer Alpa P. , Meek Mariah H. , Moyle Peter B.
Published: August 2011

Blooms of some gelatinous zooplankton are increasing worldwide, often disrupting foodwebs. Invasions of non-native jellyfish are a growing problem in many estuaries, including the San Francisco Estuary, where at least two species of Ponto-Caspian hydrozoans, Maeotias marginata Modeer, 1791 and Moerisia sp., are abundant. The present study investigated their trophic ecology, testing the following hypotheses: (1) diets over the bloom and at the diel scale are comprised of a variety of prey items; (2) hydrozoans are generalist feeders; (3) hydrozoans feed on the larvae of declining fish species; and (4) the potential for prey competition exists between the hydrozoans and two declining planktivorous fishes, striped bass (Morone saxatilis) and threadfin shad (Dorosoma petenense). Both hydrozoans ate a variety of crustaceans, most notably calanoid copepods, which were found in greater proportion in the guts than in the environment. The only fish larvae consumed were gobies. Density of Moerisia sp., was negatively correlated with gut fullness for both fishes, and diet overlap was high between shad and hydrozoans, but low for bass. Because of strong spatial and temporal overlap between hydrozoans and shad, competition for zooplankton may be occurring. These hydrozoans have invaded other systems, and should be monitored to assess potential ecological interactions in these locations.
The biology and management of Tilapia mariae (Pisces:Cichlidae) as a native and invasive species: a review
Authors: Bradford Matt , Kroon Frederieke J. , Russell D. John
Published: August 2011

Tilapia mariae (Cichlidae) is a tropical teleost, native to West African coastal drainages in the Gulf of Guinea and naturalised in the USA, Australia and possibly Russia. This paper reviews published information on the species from its native and introduced range to improve the effective management of fisheries as well as manage current infestations, reduce further spread and promote research on control measures outside its natural range. Within its natural range, the species is abundant and contributes to the local subsistence and artisanal fisheries; however, it is not extensively utilised for aquaculture. Outside its native range, it has proliferated, particularly in disturbed aquatic ecosystems. Tilapia mariae has several characteristics that make it successful in both its natural and introduced range. These include plasticity in reproductive behaviour (particularly parental care of the brood), a variety of feeding behaviours and dietary components, tolerance of a wide range of environmental conditions and aggressive behaviour to other fish species. Although tilapiine species are considered to be amongst the world’s worst invasive alien species, surprisingly little information is available on potential impacts of T. mariae on native species and aquatic ecosystems outside its native range.
Spatial patterns in the demography of a large estuarine teleost: king threadfin, Polydactylus macrochir
Authors: Moore B. R. , Welch D. J. , Simpfendorfer C. A.
Published: August 2011

Understanding spatial patterns in demographic parameters of exploited fish species is of critical importance to effective fisheries management. In the present study, patterns in demography of a large, protandrous, estuarine teleost, king threadfin, Polydactylus macrochir, were compared among three estuaries on the eastern coast of Queensland, Australia. Significant variation in age and growth was observed between fish from the Fitzroy River and those from the Mary and Brisbane Rivers, with Fitzroy River fish living longer (22 years v. 10 and 14 years, respectively), reaching a greater asymptotic length (1222-mm fork length (FL) v. 975- and 1047-mm FL, respectively), and attaining greater length-at-ages of 6 years and beyond. No difference in growth was detected between Mary and Brisbane River fish, or in total mortality among any of the sites. Fitzroy River fish were generally found to mature and change sex at greater lengths and ages than those from the Mary and Brisbane Rivers. The observed variability suggests that spatially segregated populations of P. macrochir may respond differently to fishing pressure and highlights the importance of understanding the spatial patterns in demography of exploited estuarine fish populations.
Trophic Relations of Introduced Flathead Catfish in an Atlantic River
Authors: Baumann Jessica R. , Kwak Thomas J.
Published: August 2011

The flathead catfish Pylodictis olivaris is a large piscivore that is native to the Mississippi and Rio Grande river drainages but that has been widely introduced across the United States. River ecologists and fisheries managers are concerned about introduced flathead catfish populations because of the negative impacts on native fish communities or imperiled species associated with direct predation and indirect competition from this apex predator. We studied the trophic relations of introduced flathead catfish in an Atlantic river to further understand the effects on native fish communities. Crayfish (Astacidea) occurred most frequently in the flathead catfish diet, while sunfish Lepomis spp. comprised the greatest percentage by weight. Neither of two sympatric imperiled fish species (the federally endangered Cape Fear shiner Notropis mekistocholas and the Carolina redhorse Moxostoma sp., a federal species of concern) was found in any diet sample. An ontogenetic shift in diet was evident when flathead catfish reached about 300 mm, and length significantly explained the variation in the percent composition by weight of sunfish and darters Etheostoma and Percina spp. Flathead catfish showed positive prey selectivity for taxa that occupied similar benthic microhabitat, highlighting the importance of opportunistic feeding and prey encounter rates. Flathead catfish displayed a highly variable diel feeding chronology during July, when they had a mean stomach fullness of 0.32%, but then showed a single midday feeding peak during August (mean fullness = 0.52%). The gastric evacuation rate increased between July (0.40/h) and August (0.59/h), as did daily ration, which more than doubled between the 2 months (3.06% versus 7.37%). Our findings increase the understanding of introduced flathead catfish trophic relations and the degree of vulnerability among prey taxa, which resource managers may consider in fisheries management and conservation of native fish populations and imperiled species.
Educational Development in Iran: The Pivotal Role of the Mission Schools and Alborz College
Authors: Lorentz John H.
Published: August 2011

There were many channels of Western impact on nineteenth-century Iran. The military sphere was the first and continued to be of importance throughout the nineteenth and twentieth centuries. Diplomatic interchanges, travelers and new types of economic activity were all influential in opening Iranians to awareness of another world. But perhaps the foremost channel through which the impact of the West was transmitted to Iran was education. Several areas in the educational sphere were important in the influx of Western ideas and ways into nineteenth and early twentieth century Iran. These were: students sent abroad; Western-inspired educational institutions set up by the Iranian government, and later by private individuals; and mission schools. This analysis focuses on the last of these influences and, above all, on the most renowned of the mission schools, Alborz College. In surveying the evidence, one can conclude that mission-provided Western education formed a significant chapter in the early modern period of Iranian history.
Inculcate Tehran: Opening a Dialogue of Civilizations in the Shadow of God and the Alborz
Authors: Zirinsky Michael
Published: August 2011

This essay discusses the establishment of Alborz College by American Presbyterian missionaries. Alborz's early years, before its 1940 nationalization by Iran, were shaped by the vision of its first president, Samuel Jordan, a liberal, athletic, pragmatic Christian reformer who led by example, a practitioner of what we now call “social work” and an encourager of female empowerment. Alborz and the Presbyterian mission which gave it birth grew in the context of American social history, including the religious awakening of the early nineteenth century, American doctrines of freedom and universal education, as well as the contradictory impulses of ethnocentricity and ecumenicism. The essay is based on private and governmental archival sources and the experience of the author as a high school student in Tehran.
The American College of Tehran, 1929–32: A Memorial Album
Authors: Gheissari Ali
Published: August 2011

This essay introduces a previously unpublished memorial album of the American College of Tehran compiled by a former student during the early Pahlavi period. The album contains a wide range of contributions by College faculty, associates, occasional visitors as well as fellow students and encompasses material on national history, ethics, sports, military service, mathematics and poetry, as well as numerous pencil drawings and art work. In addition there is a wide range of photographs of the College, its faculty and staff, its diverse student body, classrooms, athletics, special occasions and outdoor activities (a list of the album's contents and samples of contributions and photographs are appended to the essay). As discussed in the essay, and in manifold ways, the documentary evidence illustrates how both physically and cognitively the College provided a necessary space for participation in educational reform during the early decades of the twentieth century. Seen from this perspective, it was part of a wider context of modernization with which a broad range of individuals from different social and community backgrounds and generations identified themselves. On the whole, the album offers valuable glimpses into the social and educational aspects of the early Pahlavi Iran.
Mojtahedi and the Founding of the Arya-Mehr University of Technology
Authors: Zarghamee Mehdi
Published: August 2011

The paper presents an account of the founding of the Arya-Mehr (now Sharif) University of Technology, and the role that Dr. Mohammad Ali Mojtahedi had in its creation in 1965. The paper describes the landscape of science and technology in Iran in 1965, the year in which Shah Mohammad Reza Pahlavi appointed Mojtahedi to establish this university. It describes the various challenges that Mojtahedi faced in establishing the university, such as avoiding crippling government regulations and bureaucracy, hiring qualified faculty, attracting top students, developing an appropriate milieu for the cultivation of scientific and technological culture and, most importantly, setting the course for the university to become not only Iran's leading institution, but also one of world's credible institutions in science and engineering. The paper also discusses Mojtahedi's unique approach to these challenges, and how, despite his best intentions, he created the animosity and intrigues that resulted in his ousting in 1967. The university did in fact become Iran's leading institution in sciences and engineering, a position which it holds even today.
A comparative study of the impact of mainstream and special school placement on the behaviour of children with Autism Spectrum Disorders
Authors: Reed Phil , Osborne Lisa A. , Waddington Emma M.
Published: August 2011

The current study examined the impact of school placement in mainstream or special settings on the behavioural functioning of children with Autism Spectrum Disorders (ASD). Children were assessed at the start of the school year and then again at the end of the school year using the Strengths and Difficulties Questionnaire and the Vineland Adaptive Behavior Scale. Children with ASD made improvements in both types of placements; however, those children in specialist provisions made greater improvements in areas of conduct and socialisation. These results confirm other recent demonstrations of superior performance in special schools for children with ASD. The need to re‐address specialist school placement as a viable alternative to mainstream education for children with ASD is discussed.
‘Perceived’ competition and performance in Italian secondary schools: New evidence from OECD—PISA 2006
Authors: Agasisti Tommaso , Murtinu Samuele
Published: August 2011

In this paper, we investigate the effects of competition on the performance of Italian secondary schools as measured by maths achievement scores (PISA 2006 dataset). Competition is measured by an indicator of ‘perceived’ competition (generated from an answer provided by the schools’ principals). The methodology employed is a propensity score matching that is corrected to take into account heteroskedasticity and finite sample bias. The results show a positive effect of competition on school performance. Nevertheless, this effect is quite low (between 3.62% and 4.05% computed at the average score level) and is consistent with previous findings about educational systems in Italy and worldwide. This is relevant for policy‐making because competition appears to impact school performance even in a country like Italy where specific pro‐competitive policies are quite absent.
Power and representation: A postcolonial reading of global partnerships and teacher development through North—South study visits
Authors: Martin Fran , Griffiths Helen
Published: August 2011

This paper critically analyses the neo‐liberal discourse informing global education policy and practice. We use postcolonial theory to deconstruct the contexts for global educational partnerships, highlighting how issues of power and representation are central to their development and the learning that takes place within them. Teacher development through North—South study visits is one way of challenging teachers’ worldviews, but these are not always effective. We argue that study visit courses, where learning is facilitated by differently knowledgeable others, have the potential to be more effective, but only if the courses are underpinned by postcolonial theory and informed by socio‐cultural pedagogy.
Effects of the Big Five personality dimensions on appraisal coping, and coping effectiveness in sport
Authors: Kaiseler Mariana , Polman Remco C. J. , Nicholls Adam R.
Published: August 2011

In this study, we examined the influence of the Big Five personality dimensions (Neuroticism, Extraversion, Agreeableness, Conscientiousness, and Openness to Experience) on the appraisal (intensity, control) of a self‐selected stressor, coping, and perceived coping effectiveness. Participants were 482 athletes (305 males, 177 females) who played a variety of sports. Results indicate that the Big Five dimensions influenced coping selection, coping effectiveness, stress intensity, and perceived control of the stressors, but not the type of self‐selected stressor. In particular, Neuroticism predicted higher stressor intensity and Agreeableness lower stressor intensity. Neuroticism predicted lower perceived stressor control and Conscientiousness higher perceived stressor control. Higher levels of Neuroticism were directly and indirectly associated with more emotion and avoidance coping strategies and less problem‐focused coping strategies. The other four personality dimensions were also associated with the selection of coping strategies that were perceived to be effective. This study provides support for the notion that the Big Five personality dimensions directly influence appraisal, coping, and coping effectiveness among the sample. Coping was also influenced indirectly by personality through the appraisal process. The Neuroticism dimension was found to be associated with the selection of less adaptive coping strategies and lower levels of reported coping effectiveness. The other four personality dimensions were associated with more adaptive coping strategies that were rated as effective.
Post‐exercise ingestion of different amounts of protein affects plasma insulin concentration in humans
Authors: Morifuji Masashi , Aoyama Tomoko , Nakata Ai , Sambongi Chiaki , Koga Jinichiro , Kurihara Kunihiko , Kanegae Minoru , Suzuki Katsuhiko , Higuchi Mitsuru
Published: August 2011

The synergistic stimulating effect of combined intake of carbohydrate and protein on plasma insulin concentration has been reported previously. However, it remains unclear whether the amount of protein ingested after exercise affects the concentrations of plasma insulin and amino acids. This study of trained men compared the effects of post‐exercise co‐ingestion of carbohydrate plus different amounts of whey protein hydrolysates (WPHs) with carbohydrate alone on (1) blood biochemical parameters of carbohydrate metabolism during the post‐exercise phase, and (2) endurance performance. Eight trained men exercised continuously for 70 min. Immediately after exercise and 30, 60, 90, and 120 min later, the participants received supplements containing: (1) 17.5 g carbohydrate, (2) 3.0 g WPHs and 17.5 g carbohydrate (L‐WPH), or (3) 8.0 g WPHs and 17.5 g carbohydrate (H‐WPH). After a 2‐h recovery period, the participants performed an endurance performance test. The concentrations of blood glucose were lower and plasma insulin significantly higher in the H‐WPH trial compared with the carbohydrate trial. The concentrations of plasma amino acids were increased in a dose‐dependent manner following ingestion of different amounts of WPHs with carbohydrate. Endurance performance was not significantly different between the three trials. Co‐ingestion of carbohydrate and H‐WPH was more effective than ingestion of carbohydrate alone for stimulating insulin secretion and increasing the availability of plasma amino acids. These results suggest that plasma concentrations of amino acids during the recovery period are determined by the amount of dietary protein ingested, and that it is necessary to increase the concentration of plasma amino acids above a certain level to stimulate insulin secretion.
Gendering physical education: The role of the French State in the aftermath of the First World War
Authors: Terret Thierry
Published: August 2011

The Great War contributed greatly to challenge the gender order in France, a context that resulted in both a crisis of masculinity and a certain freedom of women. As a reaction, men and women were redefined in the aftermath of the First World War according to traditional gender expectations. This return to tradition was especially reflected in the new official discourse on physical education. Between 1919 and 1927, the so‐called “French Method of Physical Education” was written by the Military School of Joinville‐Le‐Pont and immediately imposed on the State school system for all French pupils. Consisting of three large volumes, the “French Method” offers an excellent tool to explore how the French State redefined the gender relations and presented ideal models of masculinity and femininity. The issue is of particular interest because the “French Method” became compulsory for almost half a century in France and was largely disseminated throughout the world.
Alejandro Sánchez Alvarado: Bootstrapping flatworms into the molecular age
Authors: Sedwick Caitlin
Published: August 2011

Sánchez Alvarado studies tissue regeneration in planarians.
Wee1 controls genomic stability during replication by regulating the Mus81-Eme1 endonuclease
Authors: Domínguez-Kelly Raquel , Martín Yusé , Koundrioukoff Stephane , Tanenbaum Marvin E. , Smits Veronique A.J. , Medema René H. , Debatisse Michelle , Freire Raimundo
Published: August 2011

Correct replication of the genome and protection of its integrity are essential for cell survival. In a high-throughput screen studying H2AX phosphorylation, we identified Wee1 as a regulator of genomic stability. Wee1 down-regulation not only induced H2AX phosphorylation but also triggered a general deoxyribonucleic acid (DNA) damage response (DDR) and caused a block in DNA replication, resulting in accumulation of cells in S phase. Wee1-deficient cells showed a decrease in replication fork speed, demonstrating the involvement of Wee1 in DNA replication. Inhibiting Wee1 in cells treated with short treatment of hydroxyurea enhanced the DDR, which suggests that Wee1 specifically protects the stability of stalled replication forks. Notably, the DDR induced by depletion of Wee1 critically depends on the Mus81-Eme1 endonuclease, and we found that codepletion of Mus81 and Wee1 abrogated the S phase delay. Importantly, Wee1 and Mus81 interact in vivo, suggesting direct regulation. Altogether, these results demonstrate a novel role of Wee1 in controlling Mus81 and DNA replication in human cells.
Pieces of nilpotent cones for classical groups
Authors: Achar Pramod , Henderson Anthony , Sommers Eric
Published: August 2011

We compare orbits in the nilpotent cone of typeBnB_n, that of typeCnC_n, and Kato’s exotic nilpotent cone. We prove that the number ofFq\mathbb {F}_q-points in each nilpotent orbit of typeBnB_norCnC_nequals that in a corresponding union of orbits, called a type-BBor type-CCpiece, in the exotic nilpotent cone. This is a finer version of Lusztig’s result where corresponding special pieces in typesBnB_nandCnC_nhave the same number ofFq\mathbb {F}_q-points. The proof requires studying the case of characteristic22, where more direct connections between the three nilpotent cones can be established. We also prove that the type-BBand type-CCpieces of the exotic nilpotent cone are smooth in any characteristic.
Should the U.S. National School Lunch Program continue its in‐kind food benefit? A school district‐level analysis of funding efficiency and equity
Authors: Peterson Cora , Le Grand Julian
Published: August 2011

For over 65 years, the U.S. Department of Agriculture has purchased commodity foods for the National School Lunch Program (NSLP) in an effort to support both schools and food producers. Based on data from 339 Minnesota school districts from 2001–2008, this research examined whether the NSLP's in‐kind food program is an efficient and equitable way to fund school food services. Multivariate models suggested that the program is inefficient, though offered limited insight into district‐level factors that affected utilization of commodity funding, and therefore offered less clear conclusions about equity. It was estimated that districts obtained just $0.60 in commodity food value given a $1 increase in available commodity funding over the years observed, and that the commodity program's system of “reconciled” and “rollover” funding accounted for much of this discrepancy. Based on these results, it is recommended that a cash benefit replace the NSLP's current in‐kind food benefit for schools.
Counter-comment on: Cadrin et al. (2010) “Population structure of beaked redfish, Sebastes mentella: evidence of divergence associated with different habitats. ICES Journal of Marine Science, 67: 1617–1630.”
Authors: Cadrin Steven X. , Mariani Stefano , Pampoulie Christophe , Bernreuther Matthias , Daníelsdóttir Anna Kristín , Johanssen Torild , Kerr Lisa , Nedreaas Kjell , Reinert Jákup , Sigurðsson Þorsteinn , Stransky Christoph
Published: August 2011

Cadrin, S. X., Mariani, S., Pampoulie, C., Bernreuther, M., Daníelsdóttir, A. K., Johansen, T., Kerr, L., Nedreaas, K., Reinert, J., Sigurðsson, Þ., and Stransky, C. 2011. Counter-comment on: Cadrin et al. (2010) “Population structure of beaked redfish, Sebastes mentella: evidence of divergence associated with different habitats. ICES Journal of Marine Science, 67: 1617–1630.” – ICES Journal of Marine Science, 68: 2016–2018. A one-stock hypothesis for S. mentella in the Irminger Sea was rejected in favour of one involving depth-segregated stock structure based on the best scientific information available, including recent genetic results. The depth-based hypothesis is maintained and supported, despite the criticisms by Makhrov et al. (2011), which can all be explained and refuted.
Bose–Einstein condensation of spin wave quanta at room temperature
Authors: Dzyapko O. , Demidov V. E. , Melkov G. A. , Demokritov S. O.
Published: August 2011

Spin waves are delocalized excitations of magnetic media that mainly determine their magnetic dynamics and thermodynamics at temperatures far below the critical one. The quantum-mechanical counterparts of spin waves are magnons, which can be considered as a gas of weakly interacting bosonic quasi-particles. Here, we discuss the room-temperature kinetics and thermodynamics of the magnon gas in yttrium iron garnet films driven by parametric microwave pumping. We show that for high enough pumping powers, the thermalization of the driven gas results in a quasi-equilibrium state described by Bose–Einstein statistics with a non-zero chemical potential. Further increases of the pumping power cause a Bose–Einstein condensation documented by an observation of the magnon accumulation at the lowest energy level. Using the sensitivity of the Brillouin light scattering spectroscopy to the degree of coherence of the scattering magnons, we confirm the spontaneous emergence of coherence of the magnons accumulated at the bottom of the spectrum, occurring if their density exceeds a critical value.
Dynamical magnetoelectric effects in multiferroic oxides
Authors: Tokura Yoshinori , Kida Noriaki
Published: August 2011

Multiferroics with coexistent ferroelectric and magnetic orders can provide an interesting laboratory to test unprecedented magnetoelectric (ME) responses and their possible applications. One such example is the dynamical and/or resonant coupling between magnetic and electric dipoles in a solid. As examples of such dynamical ME effects, (i) the multiferroic domain wall dynamics and (ii) the electric dipole active magnetic responses are discussed with an overview of recent experimental observations.
Spin in organics: a new route to spintronics
Authors: Koopmans Bert , Wagemans Wiebe , Bloom Francisco L. , Bobbert Peter A. , Kemerink Martijn , Wohlgenannt Markus
Published: August 2011

New developments in the nascent field of organic spintronics are discussed. Two classes of phenomena can be discerned. In hybrid organic spin valves (OSVs), an organic semiconducting film is sandwiched between two ferromagnetic (FM) thin films, aiming at magnetoresistive effects as a function of the relative alignment of the respective magnetization directions. Alternatively, organic magnetoresistance (OMAR) is achieved without any FM components, and is an intrinsic property of the organic semiconductor material. Some of the exciting characteristics of OMAR, in both electrical conductance and photoconductance, are presented. A systematic, combined experimental–theoretical study of sign changes between positive and negative magnetoresistance is shown to provide important insight about the underlying mechanisms of OMAR. A simple explanation of experimental observations is obtained by combining a ‘spin-blocking’ mechanism, an essential ingredient in the recently proposed bipolaron model, with specific features of the device physics of space charge limited current devices in the bipolar regime. Finally, we discuss possible links between the physics relevant for OMAR and that for OSVs. More specifically, weak hyperfine fields from the hydrogen atoms in organic materials are thought to be crucial for a proper understanding of both types of phenomena.
Anomalous transport properties of the half-metallic ferromagnets Co
2
TiSi, Co
2
TiGe and Co
2
TiSn
Authors: Barth Joachim , Fecher Gerhard H. , Balke Benjamin , Graf Tanja , Shkabko Andrey , Weidenkaff Anke , Klaer Peter , Kallmayer Michael , Elmers Hans-Joachim , Yoshikawa Hideki , Ueda Shigenori , Kobayashi Keisuke , Felser Claudia
Published: August 2011

In this work, the theoretical and experimental investigations of Co
2
Ti
Z
(
Z
=Si, Ge or Sn) compounds are reported. Half-metallic ferromagnetism is predicted for all three compounds with only two bands crossing the Fermi energy in the majority channel. The magnetic moments fulfil the Slater–Pauling rule and the Curie temperatures are well above room temperature. All compounds show a metallic-like resistivity for low temperatures up to their Curie temperature, above the resistivity changes to semiconducting-like behaviour. A large negative magnetoresistance (MR) of 55 per cent is observed for Co
2
TiSn at room temperature in an applied magnetic field of
μ
0
H
=4
T
, which is comparable to the large negative MRs of the manganites. The Seebeck coefficients are negative for all three compounds and reach their maximum values at their respective Curie temperatures and stay almost constant up to 950 K. The highest value achieved is −52 μVK
−1
for Co
2
TiSn, which is large for a metal. The combination of half-metallicity and the constant large Seebeck coefficient over a wide temperature range makes these compounds interesting materials for thermoelectric applications and further spincaloric investigations.
Spin control by application of electric current and voltage in FeCo–MgO junctions
Authors: Suzuki Yoshishige , Kubota Hitoshi , Tulapurkar Ashwin , Nozaki Takayuki
Published: August 2011

Efficient control and detection of spins are the most important tasks in spintronics. The current and voltage applied to a magnetic tunnel junction may exert a torque on the magnetic thin layer in the junction and cause its reversal or continuous precession. The discovery of the giant tunnelling magnetoresistance effect in ferromagnetic tunnelling junctions using an MgO barrier enabled us to obtain a large signal output from the magnetization reversal and precession. Also, the interplay of large spin configuration–electric conduction coupling provides highly nonlinear effects like the spin-torque diode effect. The negative resistance effect and amplification using it are predicted. A new discovery about a voltage-induced magnetic anisotropy change in Fe ultrathin films is also discussed.