bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulating Gene Expression through Psychotherapy: The Contribution of Noninvasive Somatic Interventions
Authors: Feinstein David , Church Dawson
Published: December 2010

Mapping the relationship between gene expression and psychopathology is proving to be among the most promising new frontiers for advancing the understanding, treatment, and prevention of mental disorders. Each cell in the human body contains some 23,688 genes, yet only a tiny fraction of a cell's genes are active or “expressed” at any given moment. The interactions of biochemical, psychological, and environmental factors influencing gene expression are complex yet relatively accessible technologies for assessing gene expression have allowed the identification of specific genes implicated in a range of psychiatric disorders, including depression, anxiety, and schizophrenia. Moreover, successful psychotherapeutic interventions have been shown to shift patterns of gene expression. Five areas of biological change in successful psychotherapy that are dependent upon precise shifts in gene expression are identified in this article. Psychotherapy ameliorates (a) exaggerated limbic system responses to innocuous stimuli, (b) distortions in learning and memory, (c) imbalances between sympathetic and parasympathetic nervous system activity, (d) elevated levels of cortisol and other stress hormones, and (e) impaired immune functioning. The thesis of this article is that psychotherapies that utilize noninvasive somatic interventions may yield greater precision and power in bringing about therapeutically beneficial shifts in gene expression that control these biological markers. The article examines the manual stimulation of acupuncture points during psychological exposure as an example of such a somatic intervention. For each of the five areas, a testable proposition is presented to encourage research that compares acupoint protocols with conventional therapies in catalyzing advantageous shifts in gene expression.
Herbert Simon's Decision-Making Approach: Investigation of Cognitive Processes in Experts
Authors: Campitelli Guillermo , Gobet Fernand
Published: December 2010

Herbert Simon's research endeavor aimed to understand the processes that participate in human decision making. However, despite his effort to investigate this question, his work did not have the impact in the “decision making” community that it had in other fields. His rejection of the assumption of perfect rationality, made in mainstream economics, led him to develop the concept of bounded rationality. Simon's approach also emphasized the limitations of the cognitive system, the change of processes due to expertise, and the direct empirical study of cognitive processes involved in decision making. In this article, we argue that his subsequent research program in problem solving and expertise offered critical tools for studying decision-making processes that took into account his original notion of bounded rationality. Unfortunately, these tools were ignored by the main research paradigms in decision making, such as Tversky and Kahneman's biased rationality approach (also known as the heuristics and biases approach) and the ecological approach advanced by Gigerenzer and others. We make a proposal of how to integrate Simon's approach with the main current approaches to decision making. We argue that this would lead to better models of decision making that are more generalizable, have higher ecological validity, include specification of cognitive processes, and provide a better understanding of the interaction between the characteristics of the cognitive system and the contingencies of the environment.
Intelligence and Substance Use
Authors: Kanazawa Satoshi , Hellberg Josephine E. E. U.
Published: December 2010

Why do some individuals choose to drink alcohol, smoke cigarettes, and use illegal drugs while others do not? The origin of individual preferences and values is one of the remaining theoretical questions in social and behavioral sciences. The Savanna-IQ Interaction Hypothesis suggests that more intelligent individuals may be more likely to acquire and espouse evolutionarily novel values than less intelligent individuals. Consumption of alcohol, tobacco, and drugs is evolutionarily novel, so the Savanna-IQ Interaction Hypothesis would predict that more intelligent individuals are more likely to consume these substances. Analyses of two large, nationally representative, and prospectively longitudinal data from the United Kingdom and the United States partly support the prediction. More intelligent children, both in the United Kingdom and the United States, are more likely to grow up to consume more alcohol. More intelligent American children are more likely to grow up to consume more tobacco, while more intelligent British children are more likely to grow up to consume more illegal drugs.
The Relationship between Religious Identity and Preferred Coping Strategies: An Examination of the Relative Importance of Interpersonal and Intrapersonal Coping in Muslim and Christian Faiths
Authors: Fischer Peter , Ai Amy L. , Aydin Nilüfer , Frey Dieter , Haslam S. Alexander
Published: December 2010

Religious affiliation has consistently been shown to help individuals cope with adversity and stressful events. The present paper argues that this proposition is valid for both Christians and Muslims, but that these religious identities foster different types of coping. In accordance with historical, cultural, and psychological accounts, it is proposed that the Christian core self is relatively individualistic, whereas the Muslim core self is oriented more toward the collective. As a consequence, it is hypothesized that when confronted with a stressful life event, Muslims are more likely to adopt interpersonal (collective) coping strategies (such as seeking social support or turning to family members), while Christians are more likely to engage intrapersonal (individualistic) coping mechanisms, such as cognitive restructuring or reframing the event. Evidence from the literature on coping strategies is reviewed and systematized. Evidence lend support to the analysis by indicating that Muslims indeed tend to use an interpersonally oriented (collective) coping style when dealing with adversity, whereas Christians are more likely to employ intrapersonally oriented (individualistic) strategies when facing comparable scenarios. Implications for theory and practice are discussed.
Systematic Survey of the Design, Statistical Analysis, and Reporting of Studies Published in the 2008 Volume of the Journal of Cerebral Blood Flow and Metabolism
Authors: Vesterinen Hanna V , Egan Kieren , Deister Amelie , Schlattmann Peter , Macleod Malcolm R , Dirnagl Ulrich
Published: December 2010

Translating experimental findings into clinically effective therapies is one of the major bottlenecks of modern medicine. As this has been particularly true for cerebrovascular research, attention has turned to the quality and validity of experimental cerebrovascular studies. We set out to assess the study design, statistical analyses, and reporting of cerebrovascular research. We assessed all original articles published in the Journal of Cerebral Blood Flow and Metabolism during the year 2008 against a checklist designed to capture the key attributes relating to study design, statistical analyses, and reporting. A total of 156 original publications were included (animal, in vitro, human). Few studies reported a primary research hypothesis, statement of purpose, or measures to safeguard internal validity (such as randomization, blinding, exclusion or inclusion criteria). Many studies lacked sufficient information regarding methods and results to form a reasonable judgment about their validity. In nearly 20% of studies, statistical tests were either not appropriate or information to allow assessment of appropriateness was lacking. This study identifies a number of factors that should be addressed if the quality of research in basic and translational biomedicine is to be improved. We support the widespread implementation of the ARRIVE (Animal Research Reporting In Vivo Experiments) statement for the reporting of experimental studies in biomedicine, for improving training in proper study design and analysis, and that reviewers and editors adopt a more constructively critical approach in the assessment of manuscripts for publication.
Environmental Basis of Cardiovascular Disease
Authors: Bhatnagar A.
Published: December 2010

Cardiovascular diseases (CVD) are the leading cause of death world-wide. In humans, under atherosclerotic lesion formation is the most prevalent cause of CVD. Although cardiac deaths are common in the great apes, the human form of atherosclerotic heart disease is rarely seen in apes. Because humans and apes are genetically similar, the high-incidence of atherosclerotic disease in humans suggests that human susceptibility to CVD may be related to the maladaptation of ancestral genes to the modern environment. The environmental basis of CVD disease is supported by studies showing that the risk of the disease is rapidly modified by changes in the environment. Several components of the natural, community and personal environments are strong determinants of CVD risk in humans. Aspects of the natural environment such as the day-night cycles, seasonal variations, sunlight, and altitude modify CVD risk. Human CVD risk is also affected by the socioeconomic factors, social networks, the built environment, and neighborhood characteristics. The impact of cultural and social environments that humans live in is transmitted over successive generations to the extent that it appears to an agent of natural selection of genes that regulate cardiovascular function and metabolism. Pollutants, toxic chemicals and changes in the global climate are associated with an increase in CVD risk. In addition, aspects of the personal environment created by lifestyle choices such as diet, physical activity and smoking profoundly affect cardiovascular health. Several studies show that a majority of CVD and diabetes in human populations could be attributed to unhealthy personal lifestyle choices and is, therefore, preventable. A better understanding of the mechanisms by which environmental factors affect CVD risk and mortality will help in designing more effective preventive and therapeutic approaches - not only to decrease risk factor burden but also to promote healthful living.
Cardiovascular Effects of Particulate-Matter Air Pollution: An Overview and Perspectives
Authors: Araujo J. A. , Brook R. D.
Published: December 2010

Air Pollution has been associated with significant adverse health effects leading to increased overall morbidity and mortality of worldwide significance. Cumulative epidemiological studies support the notion that the largest portion of air pollution-related mortality is due to cardiovascular diseases, predominantly those of ischemic nature. While both gases and particles have been linked to detrimental health effects, at the present time more evidence implicates the particulate matter (PM) components as major responsible for a large portion of the cardiovascular effects. This chapter is a general overview of the most significant epidemiological studies that support the association between PM air pollution and increased cardiovascular morbidity and mortality, along with a broad review of specific clinical and sub-clinical cardiovascular outcomes that provide insights into the potentially responsible pathobiological mechanisms.
Air Pollution and Diabetes
Authors: Wilker E. H. , Schwartz J. D.
Published: December 2010

Numerous studies have found evidence suggesting that diabetics are particularly susceptible to the health effects of air pollution. While a number of plausible pathways related to inflammation and oxidative stress have been proposed, the mechanisms underlying the observed associations remain unclear, both because of the complex nature of diabetes etiology as well as the heterogeneous composition of air pollution. This review attempts to address the major health-related areas in which diabetes has been demonstrated to influence vulnerability to ambient pollution exposures, and to provide an overview of proposed mechanisms. Given the extent of the public health and medical costs related to diabetes treatment and prevention strategies, as well as the projected increase in prevalence of this disease, identification of environmental risk factors which can be regulated may be an important public health intervention.
Ambient Particulate Matter and the Risk of Stroke
Authors: Wellenius G. A. , Gold D. R. , Mittleman M. A.
Published: December 2010

Stroke is a leading cause of long-term disability and the third leading cause of death after heart disease and cancer, both in the United States and globally. A large number of epidemiologic studies have found associations between short-term and long-term increases in particulate air pollution (PM) and risk of cardiovascular morbidity and mortality. However, the potential effects of PM on cerebrovascular morbidity and mortality have only recently been studied in detail. Large studies from the US, Europe, and Australia/New Zealand provide inconsistent support for an association between short-term increases in ambient PM levels and risk of cerebrovascular disease morbidity or mortality. The evidence in support of an association is more consistent among studies that have specifically evaluated hospitalization for ischemic stroke, although again, considerable heterogeneity across studies is observed. In contrast, findings from both ecological and cohort studies consistently show that long-term exposure to ambient PM is associated with increased risk of cerebrovascular morbidity and mortality. Given the well documented associations between ambient PM exposure and cardiac disease, as well as the putative mechanisms of these effects, it is plausible that ambient PM increase the risk of ischemic and/or hemorrhagic stroke. Studies to date broadly support this hypothesis, but additional studies are clearly needed.
Ultrafine Particles and Atherosclerosis
Authors: Araujo J. A.
Published: December 2010

Air Pollution has been associated with significant adverse health effects leading to increased cardiovascular morbidity and mortality. Epidemiological studies support the association of exposure to air particulate matter with atherosclerosis, to the extent that PM exposure can be regarded as a cardiovascular risk factor. Experimental animal work has demonstrated that this association is likely causal. The proatherogenic potential of ambient particles appears to depend on their ability to elicit systemic prooxidative and proinflammatory effects. Particle size and chemical composition seem to be important in determining their prooxidative properties. We have reported that ultrafine particles (>0.18 µm) enhance early atherosclerosis, partly due to their high content in redox cycling chemicals and their ability to synergize with known mediators in the activation of proatherogenic molecular pathways. These effects take place in parallel with increased evidence of phase 2 enzymes expression, via the electrophile-sensitive transcription factor, p45-NFE2 related transcription factor 2 (Nrf2). Exposure to ultrafine particles also results in alterations of the plasma HDL antiinflammatory function that could be indicative of systemic proatherogenic effects. This article reviews the epidemiological, clinical and experimental animal evidence that support the association of particulate matter, especially in the ultrafine size range, with systemic oxidative stress and atherosclerosis
Manufactured Nanoparticles
Authors: Kang G. S. , Gillespie P. A. , Chen L. C.
Published: December 2010

There is growing interest in engineered nanoparticles (NPs) for various medical and technological applications, but the environmental and health effects of these NPs are largely unknown. The purpose of this chapter is to review and summarize some of the recent publications pertaining to engineered NPs and their potential adverse effects on the cardiovascular system. The limitations of these studies and directions for future studies are also discussed.
Impact of surface topography and laser pulse duration for laser ablation of solar cell front side passivating SiNx layers
Authors: Hermann Sonja , Dezhdar Tara , Harder Nils-Peter , Brendel Rolf , Seibt Michael , Stroj Sandra
Published: December 2010

Local contact openings in SiNx layers that passivate the front side of solar cells offer an attractive alternative to the current standard “fire-through” screen printing process for front grid fabrication. Additionally, this technology can be used for enabling a selective emitter. In the present paper, we investigate laser ablation of SiNx layers on planar and textured silicon surfaces for various laser wavelengths and pulse durations in the nanosecond (ns) to femtosecond (fs) range. We characterize the dark J-V characteristics of diodes with laser contact openings in the SiNx layer passivating the emitter. Our results show that on alkaline textured surfaces the ablation by a ns laser produces less damage than by an ultrashort pulse laser. The dark currents of alkaline textured diodes treated with picosecond (ps) or fs lasers are one order of magnitude higher than those of ns laser treated diodes. High ideality factors furthermore indicate crystal damage in the ∼500 nm deep space charge region of the diodes. Scanning electron microscope and transmission electron microscope images of textured samples, confirm the presence of extensive and deep crystal damage after ps laser ablation, which are not observed in laser treated samples with planar surfaces. Correspondingly, for planar surfaces we find for both, ns and for ps laser ablated regions, emitter saturation current densities J0e,abl of ∼2 pA/cm2. The recombination in textured samples in contrast differs vastly for ns and ps laser ablation. The ns laser results in an only slightly increased value of 3.7 pA/cm2 while the ps laser treated sample was not evaluable due to severe crystal damage leading to effective lifetimes of <5 μs.
Isochoric heating with laser-accelerated proton beams
Authors: Carrié M. , Combis P. , Lefebvre E.
Published: December 2010

Numerical simulations are used to study acceleration of protons by intense laser pulses and the induced heating of a secondary target using this proton beam. Laser-plasma interaction and ion acceleration are modeled with a multidimensional, relativistic particle-in-cell code. Proton slowing-down and secondary target heating are computed with a two-dimensional Monte Carlo and a one-dimensional Lagrangian hydrodynamics codes. Strategies for optimization of heating uniformity include tailoring the accelerated proton spectrum with specific target geometries or laser pulse parameters. A trade-off must then be found between heating uniformity and efficiency. The parameters (temperature, depth and radius of heated zone, characteristic heating and hydrodynamics times) that could be obtained on current short pulse laser facilities, using a typical 50 fs Gaussian pulse with an intensity of several 1019 W/cm2, are explored.
Signal-to-noise analysis of biomedical photoacoustic measurements in time and frequency domains
Authors: Telenkov Sergey , Mandelis Andreas
Published: December 2010

Sensitivity analysis of photoacoustic measurements is conducted using estimates of the signal-to-noise ratio (SNR) achieved under two different modes of optical excitation. The standard pulsed time-domain photoacoustic imaging is compared to the frequency-domain counterpart with a modulated optical source. The feasibility of high-SNR continuous wave depth-resolved photoacoustics with frequency-swept (chirp) modulation pattern has been demonstrated. Utilization of chirped modulation waveforms achieves dramatic SNR increase of the periodic signals and preserves axial resolution comparable to the time-domain method. Estimates of the signal-to-noise ratio were obtained using typical parameters of piezoelectric transducers and optical properties of tissue.
Adsorption geometry, molecular interaction, and charge transfer of triphenylamine-based dye on rutile TiO2(110)
Authors: Yu Shun , Ahmadi Sareh , Zuleta Marcelo , Tian Haining , Schulte Karina , Pietzsch Annette , Hennies Franz , Weissenrieder Jonas , Yang Xichuan , Göthelid Mats
Published: December 2010

The fast development of new organic sensitizers leads to the need for a better understanding of the complexity and significance of their adsorption processes on TiO2 surfaces. We have investigated a prototype of the triphenylamine−cyanoacrylic acid (donor-acceptor) on rutile TiO2 (110) surface with special attention on the monolayer region. This molecule belongs to the type of dye, some of which so far has delivered the record efficiency of 10%–10.3% for pure organic sensitizers [W. Zeng, Y. Cao, Y. Bai, Y. Wang, Y. Shi, M. Zhang, F. Wang, C. Pan, and P. Wang, Chem. Mater. 22, 1915 (2010)]. The molecular configuration of this dye on the TiO2 surface was found to vary with coverage and adopt gradually an upright geometry, as determined from near edge x-ray absorption fine structure spectroscopy. Due to the molecular interaction within the increasingly dense packed layer, the molecular electronic structure changes systematically: all energy levels shift to higher binding energies, as shown by photoelectron spectroscopy. Furthermore, the investigation of charge delocalization within the molecule was carried out by means of resonant photoelectron spectroscopy. A fast delocalization (∼1.8 fs) occurs at the donor part while a competing process between delocalization and localization takes place at the acceptor part. This depicts the “push−pull” concept in donor−acceptor molecular system in time scale.
Past horizons in twisting algebraically special space–times
Authors: Natorf Włodzimierz
Published: December 2010

Two equations describing past marginally trapped surfaces in twisting algebraically special space–times are obtained. One of them generalizes the equation discussed by Tod for twist-free (Robinson–Trautman) metrics. The second one is solvable under certain algebraic conditions, closely related to “m > 0” and “ \documentclass[12pt]{minimal}\begin{document}$m^2 > a^2$\end{document}m2>a2” of the Kerr metric. Consequences of the existence of a null horizon are discussed. Kerr–Schild metrics admitting such horizons are shown to be of Petrov- type D.
Diamagnetic flux measurement in Aditya tokamak
Authors: Kumar Sameer , Jha Ratneshwar , Lal Praveen , Hansaliya Chandresh , Gopalkrishna M. V. , Kulkarni Sanjay , Mishra Kishore
Published: December 2010

Measurements of diamagnetic flux in Aditya tokamak for different discharge conditions are reported for the first time. The measured diamagnetic flux in a typical discharge is less than 0.6 mWb and therefore it has required careful compensation for various kinds of pick-ups. The hardware and software compensations employed in this measurement are described. We introduce compensation of a pick-up due to plasma current of less than 20 kA in short duration discharges, in which plasma pressure gradient is supposed to be negligible. The flux measurement during radio frequency heating is also presented in order to validate compensation.
Gyrokinetic statistical absolute equilibrium and turbulence
Authors: Zhu Jian-Zhou , Hammett Gregory W.
Published: December 2010

A paradigm based on the absolute equilibrium of Galerkin-truncated inviscid systems to aid in understanding turbulence [T.-D. Lee, Q. Appl. Math. 10, 69 (1952)] is taken to study gyrokinetic plasma turbulence: a finite set of Fourier modes of the collisionless gyrokinetic equations are kept and the statistical equilibria are calculated; possible implications for plasma turbulence in various situations are discussed. For the case of two spatial and one velocity dimension, in the calculation with discretization also of velocity v with N grid points (where N+1 quantities are conserved, corresponding to an energy invariant and N entropy-related invariants), the negative temperature states, corresponding to the condensation of the generalized energy into the lowest modes, are found. This indicates a generic feature of inverse energy cascade. Comparisons are made with some classical results, such as those of Charney–Hasegawa–Mima in the cold-ion limit. There is a universal shape for statistical equilibrium of gyrokinetics in three spatial and two velocity dimensions with just one conserved quantity. Possible physical relevance to turbulence, such as ITG zonal flows, and to a critical balance hypothesis are also discussed.
Implementation problem for the canonical commutation relation in terms of quantum white noise derivatives
Authors: Ji Un Cig , Obata Nobuaki
Published: December 2010

The implementation problem for the canonical commutation relation is reduced to a system of differential equations for Fock space operators containing new type of derivatives. We solve these differential equations systematically by means of quantum white noise calculus, and obtain the solution to the implementation problem.
Effect of long duration UV irradiation on diamondlike carbon surfaces in the presence of a hydrocarbon gaseous atmosphere
Authors: Riedo A. , Wahlström P. , Scheer J. A. , Wurz P. , Tulej M.
Published: December 2010

Measurements of the effect of long duration UV irradiation (up to 2905 min) of flight quality diamondlike carbon charge state conversion surfaces for application in space research in the presence of a hydrocarbon atmosphere were done. An isopropanol atmosphere was used for simulating the hydrocarbon gaseous environment for an instrument on a satellite in space. Charge state conversion surfaces are used in neutral particle sensing instruments where neutral atoms have to be ionized prior to the analysis. A narrow-band (126±5 nm) discharge lamp and a broad-band deuterium lamp (112–370 nm) were used as sources of UV radiation. The UV irradiation of a surface results in the desorption of some volatiles present on the surface and the decomposition of others. Desorption of volatiles, mostly water, is observed for both UV sources. The decomposition of the hydrocarbons and the subsequent build-up of a hydrocarbonaceous layer is only observed for the broad-band UV lamp, which is more representative for the space environment. Unfortunately, the hydrocarbonaceous layer cannot be removed thermally, i.e., it is permanent, and causes a degradation of the performance of the charge state conversion surfaces. With the present measurements we can quantify the UV influence at which the degradation of the conversion surfaces becomes noticeable.
Size, shape, composition, and electronic properties of InAs/GaAs quantum dots by scanning tunneling microscopy and spectroscopy
Authors: Gaan S. , He Guowei , Feenstra R. M. , Walker J. , Towe E.
Published: December 2010

InAs/GaAs quantum dot (QD) heterostructures grown by molecular beam epitaxy are studied using cross-sectional scanning tunneling microscopy and spectroscopy. The images reveal individual InAs QDs having a lens shape with maximum base diameter of 10.5 nm and height of 2.9 nm. Analysis of strain relaxation of the QDs reveals an indium composition varying from 65% at the base of the QD, to 95% at its center, and back to 65% at its apex. Room-temperature tunneling spectra acquired 3–4 nm from the center of a dot show a peak located in the upper part of the GaAs band gap originating from the lowest electron confined state of the QD, along with a tail in the conductance extending out from the valence band and originating from QD hole states. A computational method is developed for simulating the tunneling spectra using effective-mass bands treated in an envelope function approximation. By comparison of the computations to low-current spectra, the energy of the lowest electron, and highest hole QD states are determined. These energies are found to be in reasonably good agreement both with optical measurements and prior theoretical predictions of Wang et al. [Phys. Rev. B 59, 5678 (1999)].
Experimental studies on coaxial vortex loops
Authors: Mariani R. , Kontis K.
Published: December 2010

An experimental study has been conducted on the formation and propagation of coaxial vortex loops using a shock tube facility. The study aimed at evaluating the flow characteristics of pairs of corotating vortex rings that generate the leapfrogging phenomenon. The driver and driven gas of the shock tube were air. Three driver pressures were used (4, 8, and 12 bars) with the driven gas being at ambient conditions. The Mach numbers of the shock wave generated inside the shock tube were 1.34, 1.54, and 1.66, respectively. The sudden expansion present at the diaphragm location effectively decreased the Mach number value of the traveling shock wave. Results showed that a pair of vortex rings staggered with respect to time and with the same direction rotation lead to leapfrogging. Results also indicated that the number of leapfrogging occurrences is related to the Reynolds number of the vortex ring pairs with a decrease in leapfrogs at higher Reynolds numbers.
Improved epitaxy of ultrathin praseodymia films on chlorine passivated Si(111) reducing silicate interface formation
Authors: Gevers S. , Flege J. I. , Kaemena B. , Bruns D. , Weisemoeller T. , Falta J. , Wollschläger J.
Published: December 2010

Ultrathin praseodymia films have been deposited on both Cl-passivated and nonpassivated Si(111) substrates by molecular beam epitaxy. Comparative studies on the crystallinity and stoichiometry are performed by x-ray photoelectron spectroscopy, x-ray standing waves, and x-ray reflectometry. On nonpassivated Si(111) an amorphous silicate film is formed. In contrast, praseodymia deposited on Cl-passivated Si(111) form a well-ordered crystalline film with cubic-Pr2O3 (bixbyite) structure. The vertical lattice constant of the praseodymia film is increased by 1.4% compared to the bulk value. Furthermore, the formation of an extended amorphous silicate interface layers is suppressed and confined to only one monolayer.
Rarefaction criterion and non-Fourier heat transfer in hypersonic rarefied flows
Authors: Wang Zhihui , Bao Lin , Tong Binggang
Published: December 2010

As a hypersonic flow transits from continuous to more and more rarefied, both the bow shock wave and the boundary layer over a leading edge will gradually become thickening, touching, and interlacing with each other, characterizing the evolution of the flow field structure. Correspondingly, an increasing nonlinear non-Fourier feature emerges from the aeroheating instead of the linear Fourier’s law. An intuitive theoretical model is proposed, and it is found that the ratio of the non-Fourier’s part to Fourier’s part of the heat flux term is a universal flow parameter to predict and describe both the physical phenomena above-mentioned. This model leads to a physically meaningful criterion to classify hypersonic rarefied flow regimes. New conclusions obtained are validated by present direct simulation Monte Carlo results.
Single-pixel coherent diffraction imaging
Authors: Lee Kanghee , Ahn Jaewook
Published: December 2010

We demonstrate single-pixel coherent diffraction imaging, whereby broadband terahertz waveforms passed through a slanted phase retarder (SPR), diffracted from an object, were measured by a terahertz detector located in the far field. For one dimensional imaging, the fixed-location single-pixel broadband detector simultaneously measured all the spatial frequency components of the object because the frequency components of the source maintain a one-to-one correspondence with the object’s spatial frequency. For two dimensional imaging, the angular position of the SPR enabled the diffracted terahertz wave to carry an angular projection image of the object.
Communication: Experimental proof of symmetry breaking in tilted smectics composed of molecules with axial chirality
Authors: Glogarová Milada , Hampl František , Lejček Lubor , Novotná Vladimíra , Svoboda Jiří , Cigl Martin
Published: December 2010

For the first time, domains with twisted structures have been established in planar samples of achiral compounds in tilted smectic C phase. This evidences separation of molecular conformers differing in the sense of axial chirality and confirms polar \documentclass[12pt]{minimal}\begin{document}$C_2$\end{document}C2 symmetry of these domains. A simple model considering polar surface anchoring energy and bulk energy of the twist can account for this finding. Conditions for coexistence of twisted and homogeneous domains are discussed.
Amplitude scaling of a static wrinkle at an oil-air interface created by dielectrophoresis forces
Authors: Brown C. V. , Al-Shabib W. , Wells G. G. , McHale G. , Newton M. I.
Published: December 2010

Dielectrophoresis forces have been used to create a static periodic wrinkle with a sinusoidal morphology on the surface of a thin layer of 1-decanol oil. The surface deformation occurs when a voltage V is applied between adjacent coplanar strip electrodes in an interdigitated array onto which the oil film is coated. It has been shown experimentally that the peak-to-peak amplitude A of the wrinkle scales according to the functional form A∝V2 exp(-αh¯/p) for a range of oil film thicknesses h¯ (between 15 and 50 μm) and wrinkle pitches p (160, 240, and 320 μm).
Real-time direct measurement of field rise time and dynamic instability of perpendicular writers
Authors: Czoschke Peter , Kaka Shehzaad , Gokemeijer N. J. , Franzen Scott
Published: December 2010

A method is presented to measure the dynamic write field of a perpendicular recording head directly in the time domain using a tunneling magnetoresistive read sensor. The method is used to measure the magnetic field rise time of two different writer designs and real-time measurements of the write field without averaging are demonstrated, enabling investigation of transient switching behavior that would not be observed with stroboscopic or frequency-domain techniques. A dynamic instability is observed and characterized in a particular writer design and is attributed to the insertion of an antiferromagnetic coupling layer in the writer pole.
Atomic layer deposition of CuCl nanoparticles
Authors: Natarajan G. , Maydannik P. S. , Cameron D. C. , Akopyan I. , Novikov B. V.
Published: December 2010

We report the growth of copper (I) chloride by atomic layer deposition. CuCl was deposited as nanoparticle arrays whose size and density were controlled by the process conditions. The nanoparticles were deposited using the self-limiting reaction of [bis(trimethylsilyl)acetylene]-(hexafluoroacetylacetonato)-copper(I) and hydrogen chloride. UV absorption measurements showed the characteristic Z1,2 and Z3 exciton absorption bands of CuCl. A strong UV emission was observed at 5 K from the free exciton Z3 and bound exciton I1 at 386.7 and 390.6 nm, respectively. A previously unreported visible emission band at 408 nm was also observed and attributed to the acceptor level of Cu vacancies.
Polarity effect on interfacial reactions at soldered junctions of electrically stressed thermoelectric modules
Authors: Liao Chien-Neng , Chen Wen-Tai , Lee Ching-Hua
Published: December 2010

Polarity-dependent interfacial reaction at soldered junctions of bismuth telluride based thermoelectric modules is reported. Using infrared thermal imaging system asymmetrical heating at various soldered junctions of thermoelectric modules under electrical stressing was directly observed. It is suggested that electromigration (EM) coupled with asymmetrical heating leads to preferential consumption of Ni barrier and formation of Ni3Sn4, SnTe, and SbSn compounds at the cathode junction of p-type element. By measuring the EM-induced Sn atomic flux, the product of diffusivity and effective charge number, DZ∗, was determined to be 10−8–10−9 cm2/s at 200 °C.
Temperature dependence of current-voltage characteristics of Ni–AlGaN/GaN Schottky diodes
Authors: Lim Wantae , Jeong Jae-Hyun , Lee Jae-Hoon , Hur Seung-Bae , Ryu Jong-Kyu , Kim Ki-Se , Kim Tae-Hyung , Song Sang Yeob , Yang Jong-In , Pearton S. J.
Published: December 2010

Ni–AlGaN/GaN Schottky barrier diodes (SBDs) with lateral geometry were fabricated on sapphire substrates. At 300 K, devices with 500-μm-diameter Schottky contacts exhibited breakdown voltage (VB) of 765 V, forward current (IF) of 0.065 A at 1.5 V, and specific on-resistance (Ron) of 81.3 mΩ cm2, producing a figure-of-merit (VB2/Ron) of ∼7.2 MW cm−2. Measured in multifinger patterns, the same parameters were 420 V, 3.2 A, 4.6 mΩ cm2, and 38.4 MW cm−2, respectively, at 300 K. With the increase in measurement temperature from 300 to 450 K, SBDs with dimensions of 3000×3000 μm2 showed larger effective barrier heights (0.8 eV at 300 K and 1.27 eV at 475 K) and a slightly negative temperature coefficient (−0.48 V K−1) for reverse breakdown voltage, while there was a little change in reverse leakage current. These results show the strong influence of barrier height inhomogeneity on the temperature dependence of apparent barrier heights obtained through current-voltage measurements.
Direct imaging of boron segregation to extended defects in silicon
Authors: Duguay S. , Philippe T. , Cristiano F. , Blavette D.
Published: December 2010

Silicon was implanted with a high boron dose (5×1015 at. cm−2) at 30 keV and further annealed at 950 °C for 30 s. The sample was analyzed using transmission electron microscopy (TEM) and atom probe tomography (APT). TEM images revealed the presence of a high density of dislocation loops (∼1011/cm−2) distributed around the projected range of implanted atoms. APT reconstructions showed local enrichment of boron in the form of loops that were interpreted as Cottrell atmosphere. Boron enriched rods, interpreted as the {113} defects, were also observed. Segregation energies of boron atoms to these defects were estimated to be ∼0.35 eV.
Origin of ferromagnetism in self-assembled Ga1−xMnxAs quantum dots grown on Si
Authors: Wang S. L. , Chen L. , Meng K. K. , Xu P. F. , Meng H. J. , Lu J. , Yan W. S. , Zhao J. H.
Published: December 2010

Self-assembled Ga1−xMnxAs magnetic semiconductor quantum dots have been grown on Si (001) substrates using droplet epitaxy by molecular-beam epitaxy. Structural characterization reveals that these dots possess a zinc-blende lattice. The Ga1−xMnxAs quantum dots with 8% Mn content are ferromagnetically soft and slightly anisotropic at low temperature, and show the superparamagnetic behavior with a blocking temperature of 20 K in the in-plane direction. Moreover, the results of x-ray absorption near edge structure provide direct evidences for the substitutional Mn2+ ion with a half-filled d5 configuration for the Ga site, suggesting the hole-mediated ferromagnetism in zero-dimensional Ga1−xMnxAs quantum dots.
Collapse of charge ordering and enhancement of magnetocaloric effect in nanocrystalline La0.35Pr0.275Ca0.375MnO3
Authors: Phan M. H. , Chandra S. , Bingham N. S. , Srikanth H. , Zhang C. L. , Cheong S. W. , Hoang T. D. , Chinh H. D.
Published: December 2010

We demonstrate the possibility of enhancing both the magnetocaloric effect (MCE) and refrigerant capacity (RC) in nanostructured mixed phase manganites. A comparative study of the magnetic and magnetocaloric properties of La0.35Pr0.275Ca0.375MnO3 in single crystalline and nanocrystalline forms is presented. While the conventional trend is reduction of magnetization and MCE with nanostructuring, we show that the opposite is true in the case of mixed phase manganites. The charge-ordered state is largely suppressed and ferromagnetic order is established in the nanocrystalline sample with an average particle size of 50 nm. Consequently, a strong enhancement of MCE and RC and a strong reduction of thermal and field hysteresis losses are achieved in the nanocrystalline sample. This finding opens up a way of exploring magnetic refrigerant materials at the nanometer scale for active magnetic refrigerators.
Low-frequency noise behavior of tunneling field effect transistors
Authors: Wan J. , Le Royer C. , Zaslavsky A. , Cristoloveanu S.
Published: December 2010

We report on the low-frequency noise (LFN) properties of tunneling field effect transistors (TFETs) fabricated on silicon-on-insulator substrate. Unlike conventional large FETs, where LFN obeys a 1/f frequency dependence, in large TFETs the LFN is dominated by random telegraph signal (RTS) noise characterized by 1/f2 slope. We explain this unique LFN behavior by the local junction control of the tunneling drain current, which involves few traps in a small area. The origin of RTS noise is corroborated by the gate length independence of the ID-VGS characteristics of TFETs. The relatively high amplitude of RTS noise in TFETs will have circuit design implications.
Nonlinear electrical properties of Si three-terminal junction devices
Authors: Meng Fantao , Sun Jie , Graczyk Mariusz , Zhang Kailiang , Prunnila Mika , Ahopelto Jouni , Shi Peixiong , Chu Jinkui , Maximov Ivan , Xu H. Q.
Published: December 2010

This letter reports on the realization and characterization of silicon three-terminal junction devices made in a silicon-on-insulator wafer. Room temperature electrical measurements show that the fabricated devices exhibit pronounced nonlinear electrical properties inherent to ballistic electron transport in a three-terminal ballistic junction (TBJ) device. The results show that room temperature functional TBJ devices can be realized in a semiconductor material other than high-mobility III-V semiconductor heterostructures and provide a simple design principle for compact silicon devices in nanoelectronics.
InGaAs heterostructure formation in catalyst-free GaAs nanopillars by selective-area metal-organic vapor phase epitaxy
Authors: Shapiro J. N. , Lin A. , Wong P. S. , Scofield A. C. , Tu C. , Senanayake P. N. , Mariani G. , Liang B. L. , Huffaker D. L.
Published: December 2010

We investigate axial GaAs/InGaAs/GaAs heterostructures embedded in GaAs nanopillars via catalyst-free selective-area metal-organic chemical vapor deposition. Structural characterization by transmission electron microscopy with energy dispersive x-ray spectroscopy (EDS) indicates formation of axial InxGa1−xAs (x∼0.20) inserts with thicknesses from 36 to 220 nm with ±10% variation and graded Ga:In transitions controlled by In segregation. Using the heterointerfaces as markers, the vertical growth rate is determined to increase linearly during growth. Photoluminescence from 77 to 290 K and EDS suggest the presence of strain in the shortest inserts. This capability to control the formation of axial nanopillar heterostructures is crucial for optimized device integration.
High-performance organic field-effect transistors based on copper/copper sulphide bilayer source-drain electrodes
Authors: Gu Wen , Jin Weipeng , Wei Bin , Zhang Jianhua , Wang Jun
Published: December 2010

We demonstrate an organic field-effect transistor (OFET) using copper (Cu) and copper sulfide (CuxS) as the source-drain electrodes. The OFET using Cu/CuxS results in a fivefold higher field-effect mobility and a 12 V reduction in threshold voltage as compared with the conventional devices with gold electrodes. The improvements of device performances are attributed to the enhancement of charge-injection. X-ray photoelectron spectroscopy revealed that sulfate ions were formed during deposition, which is considered to be responsible for the improvements.
dc-switchable and single-nanocrystal-addressable coherent population transfer
Authors: Gunceler Deniz , Bulutay Ceyhun
Published: December 2010

Achieving coherent population transfer in the solid-state is challenging compared to atomic systems due to closely spaced electronic states and fast decoherence. Here, within an atomistic pseudopotential theory, we offer recipes for the stimulated Raman adiabatic passage in embedded silicon and germanium nanocrystals. The transfer efficiency spectra display characteristic Fano resonances. By exploiting the Stark effect, we predict that transfer can be switched off with a dc voltage. As the population transfer is highly sensitive to structural variations, with a choice of a sufficiently small two-photon detuning bandwidth, it can be harnessed for addressing individual nanocrystals within an ensemble.
Reexamining Contemporary Urbanism in the United States: Convenient Mix of the Old and New
Authors: Fan Yingling
Published: December 2010

This paper introduces a unique approach for characterizing contemporary urban dynamics in US cities and metropolitan areas. The proposed approach utilizes a socially and spatially integrated framework, and combines the traditional factorial ecology analysis with a novel spatial interpolation technique. The approach is demonstrated on a mid-size, decentralized metropolitan area in the US. It is found that agglomeration, sprawl, gentrification, and poverty concentration coexist in the study region, and that, despite the physical proximity, gentrified areas are largely isolated from deprived areas. The findings, although not surprising when placed in the broader urbanism literature, are not explainable by any single ‘school’ of urbanism. Researchers are recommended to adjudicate among the old and new models of urbanism and focus on integrated knowledge such as the growing threats of geographic inequity and spatial injustice in contemporary metropolitan areas.
Visceral Difference: Variations in Feeling (Slow) Food
Authors: Hayes-Conroy Allison , Hayes-Conroy Jessica
Published: December 2010

This paper responds to concerns over a lack of diversity in alternative food movements by entertaining the possibility of understanding difference as a visceral process—a process of bodily feeling/sensation. Participatory research within and around the Slow Food (SF) movement reveals the complex role of feelings in motivating food actions and activism. On the whole, the cocreated data from this research illustrate that food is never ingested by itself: in the body, molecular connections develop between food and a countless array of other factors. Thus, food and food movements come to feel differently in different bodies as a result of inner-connected biological and social forces. In paying attention to such biosocial processes alternative food movements like SF may develop new under-standings as to why they activate some people to participate in alternative food practices while chilling others. Accordingly the paper suggests that attentiveness to visceral feeling could enhance the ability of food movements to mobilize across difference.
Learning through Contact? The Effects on Earnings of Immigrant Exposure to the Native Population
Authors: Tammaru Tiit , Strömgren Magnus , Stjernström Olof , Lindgren Urban
Published: December 2010

Factors influencing immigrant labour-market outcomes have received increased scholarly attention lately. A recent research focus has been the effects of residential setting on labour-market outcomes. This study brings a new dimension to this emerging body of research, introducing the role played by workplace composition, in addition to place of residence, in immigrant earnings. Based on Swedish longitudinal register data, ordinary least squares regression is used to examine effects of previous exposure to natives on earnings in three immigrant cohorts (1990, 1995, and 2000) five years after arrival. Besides controlling for individual characteristics and various labour-market attributes, a two-step Heckman correction procedure is applied to take into account the selectivity of entering the Swedish labour market. The main finding of the study is that exposure to the native population at the workplace is more important than residential exposure for predicting immigrant earnings.
How the Brain Makes the World Appear Stable
Authors: Bridgeman Bruce
Published: December 2010

Space constancy, the appearance of a stable visual world despite shifts of all visual input with each eye movement, has been explained historically with a compensatory signal (efference copy or corollary discharge) that subtracts the eye movement signal from the retinal image shift accompanying each eye movement. Quantitative measures have shown the signal to be too small and too slow to mediate space constancy unaided. Newer theories discard the compensation idea, instead calibrating vision to each saccadic target.