bluuebunny/crossref_metadata_2025 huggingface dataset:
Point interactions: boundary conditions or potentials with the Dirac delta function
Authors: De Vincenzo Salvatore , Sánchez Carlet
Published: November 2010

We study the problem of a nonrelativistic quantum particle moving on a real line with an idealized and localized singular interaction with zero range at x = 0 (i.e., a point interaction there). This kind of system can be described in two ways: (i) by considering an alternative free system (i.e., without the singular potential) but excluding the point x = 0 (In this case, the point interaction is exclusively encoded in the boundary conditions.) and (ii) by explicitly considering the singular interaction by means of a local singular potential. In this paper we relate, compare, and discuss, in a simple and pedagogical way these two equivalent approaches. Our main goal in this paper is to introduce the essential ideas about point interactions in a very accesible form to advanced undergraduates.
s-wave scattering and the zero-range limit of the finite square well in arbitrary dimensions
Authors: Farrell Aaron , van Zyl Brandon P.
Published: November 2010

We examine the zero-range limit of the finite square well in arbitrary dimensions through a systematic analysis of the reduced, s-wave, two-body, time-independent Schrödinger equation. A natural consequence of our investigation is the requirement of a delta function multiplied by a regularization operator to model the zero-range limit of the finite-square well when the dimensionality is greater than one. The case of two dimensions turns out to be surprisingly subtle, and needs to be treated separately from all other dimensions.
The information loss for QCD matter in mini black holes at LHC
Authors: Zomorrodian Mohammad Ebrahim , Sepehri Alireza , Moradi Marjaneh Aliakbar
Published: November 2010

In this paper we find information loss in mini black holes at LHC by extending the Horowitz and Maldacena mechanism to gluons and calculate the information transformation from the collapsing matter to the state of outgoing Hawking radiation for gluons, quarks, and mesons. Next, we calculate the total cross-section for mesons produced from black holes at LHC. We conclude that the more the mass of the quark within the hadrons, the lower is the cross-section. Then, we consider the effect of quarks inside the black hole on the density matrix of individual quarks within the meson outside of a black hole. At the end, we show that information is not lost in black holes if we ignore interactions between particles inside the event horizon in comparison with the effect of a black hole on particles. However, we observe that the unstable condition of excited black holes causes information loss in them. After that, we anticipate quantum black hole production by using electron–positron annihilation modeling at TeV centre of mass energies and compare the corresponding cross-sections calculated, at this stage, for different black hole states. Finally, we calculate the dependence of gluon tree level amplitudes to their thermal distributions near mini black holes at LHC.
Re-scaling of energy in stringy charged black hole solutions using approximate symmetries
Authors: Sharif M. , Waheed Saira
Published: November 2010

This paper examines the energy problem in General Relativity using approximate Lie symmetry methods for differential equations. We evaluate second-order approximate symmetries of the geodesic equations for the stringy charged black hole solutions. We conclude that energy must be re-scaled by some factor in the second-order approximation.
Squeal vibrations, glass sounds, and the stick-slip effect
Authors: Patitsas A. J.
Published: November 2010

The origin of the squeal acoustic emissions when a chalk is rubbed on a blackboard or better on a ceramic plate, and those when a wet finger is rubbed on a smooth surface, such as a glass surface, is sought in the stick-slip effect between the rubbing surfaces. In the case of the squealing chalk, the stick-slip effect is anchored by shear modes of vibration in about a 0.3 mm thick chalk powder band at the rubbing interface, while in the case of the wet finger on glass, by such modes in a band comprising the finger skin. Furthermore, there are the interfacial bands at the contact areas that result in the decrease of the friction coefficient with relative velocity of slide, i.e., the condition for the stick-slip effect to occur. Such bands are basically composed of the asperities on the surface of the chalk band and of the epidermis ridges and the water layer, respectively.
Particle-in-cell analysis of beam-wave interaction in gyrotron cavity with tapered magnetic field
Authors: Kumar Anil , Khatun Hasina , Kumar Nitin , Singh Udaybir , Vyas V. , Sinha A. K.
Published: November 2010

A commercially available electromagnetic simulator — MAGIC, a particle-in-cell (PIC) code — has been used to carry out a comparative study of the beam-wave interaction under uniform and tapered magnetic field profiles of a 42 GHz, 200 kW gyrotron. The magnetic field profile across the resonant cavity varies by ±6.5% with a peak value of 1.615 T. The MAGIC simulation shows the desire performance of the gyrotron under both magnetic field conditions with an operating mode TE03 and a pitch factor of 1.26. The analysis of the simulated results show that stability in the power growth was reached more quickly and achieved higher output power in the case of a tapered magnetic field.
Resonances in the dipositronium system: Rydberg states
Authors: DiRienzi Joseph , Drachman Richard J.
Published: November 2010

We were previously successful in representing series of Ps + H scattering resonances as mainly due to quasi-bound Rydberg states in either the closed e+ + H– or Ps– + H+ system. An obvious extension would be to investigate the analogous Ps + Ps system, as either e+ + Ps– or e– + Ps+. Here we treat the system in four increasingly complete approximations: with and without including electron and positron symmetry and charge conjugation symmetry. A comparison is made with previous calculations, and in an Appendix the relationship between quasi-bound states and scattering resonances is clarified.
LOVE AND APPEAL IN STANDARD COUPLES
Authors: RINALDI SERGIO , ROSSA FABIO DELLA , DERCOLE FABIO
Published: November 2010

Through the analysis of a mathematical model we construct in this paper the full catalog of possible love stories among standard (i.e. secure and non-synergic) individuals. For this, we first distinguish between robust and fragile couples, i.e. couples which have one or two stable equilibria. We also distinguish between high and low quality relationships by looking at the sign of the feelings among the partners. Finally, we split fragile couples into two distinct classes, namely those that start from the state of indifference to evolve toward their most desirable equilibrium, as opposed to those that have an unfavorable evolution. The boundaries separating the various classes in any two-dimensional parameter space are either bifurcation curves or special curves characterized by the annihilation of a suitably defined indicator associated to the equilibria or to their basins of attraction. The analysis is performed in part analytically and in part numerically (through continuation methods), and is mainly focused on the role of the appeals of the individuals. The results are in agreement with common wisdom and observations and show, in particular, that love stories can evolve positively even if one of the two individuals has negative feelings in the initial phase of the relationship.
CIRCUIT MIMICKING TiO2 MEMRISTOR: A PLUG AND PLAY KIT TO UNDERSTAND THE FOURTH PASSIVE ELEMENT
Authors: SODHI AVANTIKA , GANDHI GAURAV
Published: November 2010

A plug-and-play kit that can be used as a teaching aid in high school has been designed, which mimics the behavior of recently discovered TiO2 based memristor. The circuit uses easily available off-the-shelf components to emulate a memristor. SPICE simulations and lab results are shown to validate the proposed circuit.
A SIMPLE CIRCUIT WITH DYNAMIC LOGIC ARCHITECTURE OF BASIC LOGIC GATES
Authors: CAMPOS-CANTÓN I. , PECINA-SÁNCHEZ J. A. , CAMPOS-CANTÓN E. , ROSU H. C.
Published: November 2010

We report experimental results obtained with a circuit possessing dynamic logic architecture based on one of the theoretical schemes proposed by H. Peng and collaborators in 2008. The schematic diagram of the electronic circuit and its implementation to get different basic logic gates are displayed and discussed. In particular, we show explicitly how to get the electronic NOR, NAND and XOR gates. The proposed electronic circuit is easy to build because it employs only resistors, operational amplifiers and comparators.
BREAKING A CHAOTIC CRYPTOGRAPHIC SCHEME BASED ON COMPOSITION MAPS
Authors: LI CHENGQING , ARROYO DAVID , LO KWOK-TUNG
Published: November 2010

Recently a chaotic cryptographic scheme based on composition maps was proposed. This paper studies the security of the scheme and reports the following problems: (1) the scheme can be broken by a differential attack with 6 + ⌈ log L(MN)⌉ chosen plaintexts, where MN is the size of the plaintext and L is the number of different elements in plaintext; (2)the two composition maps both do not work as a secure and efficient source of random numbers; (3)the scheme is not sensitive to the changes of the plaintext.
EXISTENCE CONDITIONS OF THIRTEEN LIMIT CYCLES IN A CUBIC SYSTEM
Authors: YANG JUNMIN , HAN MAOAN , LI JIBIN , YU PEI
Published: November 2010

In this paper, we study a cubic system and obtain a concrete condition under which the cubic system has 13 limit cycles.
BIFURCATIONS OF LIMIT CYCLES AND CENTER PROBLEM FOR A CLASS OF CUBIC NILPOTENT SYSTEM
Authors: LIU YIRONG , LI JIBIN
Published: November 2010

For a class of cubic nilpotent system, the formulae of the first eight quasi-Lyapunov constants are obtained. We show that the origin of this system is a center if and only if the first eight Lyapunov constants are zeros. Under a small perturbation, eight limit cycles can be created from the eight-order weakened focus.
CHARACTERIZATION, TEST AND LOGIC SYNTHESIS OF NOVEL CONSERVATIVE AND REVERSIBLE LOGIC GATES FOR QCA
Authors: DAS KUNAL , DE DEBASHIS
Published: November 2010

Quantum dot cellular automaton (QCA) is an emerging technology in the field of nanotechnology. Reversible logic is emerging as a promising computing paradigm with applications in low-power quantum computing and QCA in the field of very large scale integration (VLSI) design. In this paper, we worked on conservative logic gate (CLG) and reversible logic gate (RLG). We examined that RLG and CLG are two classes of logic family intersecting each other. The intersection of RLG and CLG is parity preserving reversible (PPR) or conservative reversible logic gate (CRLG). We proposed in this paper, three algorithms to find different k × k RLG as well as CLG. Here, we demonstrate only the most promising two proposed gates of different categories. We compared the results with that of the previous Fredkin gate. The result shows that logic synthesis using above two gates will be a promising step towards the low-power QCA design era. We have shown a parity preserving approach to design all possible CLG. We also discuss a coupled Majority–minority-Voter (MmV) in a single nanostructure, dual outputs are driven simultaneously. This MmV gate is used for implementing n variables symmetric functions, testing the conservative gates as we explained that parity must be preserved if Majority and Minority output are same as input as well as output of CLG.
TEM-BASED INVESTIGATIONS ON CVD-ASSISTED GROWTH OF ZnO NANOWIRES INSIDE NANOCHANNELS OF ANODIZED ALUMINUM OXIDE TEMPLATE
Authors: DEULKAR SUNDEEP H. , YO HWEI-JANG , HUANG JOW-LAY
Published: November 2010

The role of Chemical Vapor Deposition's (CVD) temperature and time duration on the mass transport properties and repercussions of these properties on the crystalline growth of ZnO nanowires inside Anodic Aluminum Oxide (AAO) nanotubes (aspect ratio = 1500) have been investigated.

CVD assisted growth of nanowires in AAO nanochannels was carried out for 27 min at deposition temperature of 813 K (A1) and for 180 min at 903 K (A2) under identical gas flow rates ( Ar : 23 sccm and O2 : 0.45 sccm) under a chamber pressure of 4.45 torr.

Electron diffraction patterns (SAED) of the ZnO diffused inside A1 nanotube (exposed in Focused Ion Beam milled cross-sections) showed a ringed pattern, signifying polycrystalline morphology at the tip as well as the channel bottom. For A2, a single crystal formation at least in the tip region was confirmed by the SAED pattern while the corresponding High Resolution TEM image (HRTEM) revealed a lattice spacing of 0.24 nm corresponding to the (1 0 1) growth direction of zincite (JCPDS-36-1451).

Chemical composition of the nanowires, reflected the inherent stoichiometry of preferentially nucleated ZnO in the grooved orifices of individual nanopores. Data points of normalised values of the Zn concentration (TEM-EDS line scan) versus penetration depth (~ 0.6 μm), were empirically fitted with solutions of modified Fickian diffusion equation in 1-D. The Diffusion coefficient values of the order of 0.06 nm2 s-1 and 0.22 nm2 s-1 were obtained for ZnO flow inside nanochannels of A1 and A2, respectively. Observed variations, in diffusivity and relative density, have been explained qualitatively by considering the transport of ZnO inside the nanochannels as arising from superposition of the temperature dependent contributions of the convectional viscous creep and surface diffusion components.
OPTIMIZATION OF CNTs PRODUCTION USING FULL FACTORIAL DESIGN AND ITS ADVANCED APPLICATION IN PROTEIN PURIFICATION
Authors: MUBARAK N. M. , YUSOF FARIDAH , ALKHATIB M. F. , AMEEN EMAD , KHALID M. , MOHAMMED AL SAADI. , MUATAZ A. , QUDSIEH I. Y. , RASHMI W.
Published: November 2010

Carbon nanotubes (CNTs) have been successfully synthesized by using in-house fabricated Double Stage Chemical Vapor Deposition (DS-CVD) technique, using acetylene (C2H2) and hydrogen (H2) as the precursor gases. The purity, morphology and the structure of CNTs were then characterized using Field Emission Scanning Microscope (FESEM), Transmission Electron Microscope (TEM) and Thermogravimetric Analysis (TGA). The effects of the process parameters were examined whereby the experimental design of the investigation was conducted using Design Expert® Version 6.0.8. The statistical analysis reveals that the optimized conditions for the best CNTs yield production at 850°C reaction temperature, 60 min reaction time, with gas flow rates at 40 and 150 ml/min for C2H2 and H2 , respectively. The CNTs produced were successfully used as column chromatographic media. Due to its nanosized structured dimension, CNTs' have tremendously large surface area and that lead to highly efficient protein purification. Skim latex protein has been used as the model protein and we aim to recover useful proteins and enzymes from this known wasteful material. During the purification, the process parameters such as pH and ionic strength of the running buffer were optimized to enhance protein purification. Results reveal that CNTs behave efficiently as a hydrophobic interaction chromatographic media.
INFLUENCE OF INHOMOGENEITY OF A MULTILAYER STRUCTURE ON REDISTRIBUTION OF INFUSED DOPANT DURING PRODUCTION — A BIPOLAR TRANSISTOR
Authors: PANKRATOV E. L.
Published: November 2010

It has been recently shown, that inhomogeneity of a multilayer structure leads to increasing of sharpness of diffusion-junction rectifier (see, for example, Refs. 1–3), which was formed in the multilayer structure. It has also been shown, that together with increasing sharpness the homogeneity of impurity distribution in doped area increases. In this paper both the effects (increasing of the sharpness of diffusion-junction rectifier and increasing the homogeneity of impurity distribution) have been used for production of a system of p-n-junctions (a bipolar transistors). Annealing time has been optimized for simultaneously increasing the sharpness and the homogeneity.
CHARACTERISTIC PHOTOLUMINESCENCE OF SWCNT/CdS NANOHYBRID SYNTHESIZED BY A SIMPLE CHEMICAL ROUTE
Authors: PAUL RIMA , KUMBHAKAR P. , MITRA A. K.
Published: November 2010

The authors report a simple chemical technique to prepare a hybrid nanostructure of single wall carbon nanotubes (SWCNT) with CdS nanocrystals. By chemical reaction of cadmium acetate and sodium sulphide in the sodium dodecyl sulphate (SDS) solution containing SWCNT, cadmium sulphide quantum dots (QDs) of average size 5.5 nm are decorated onto the walls of SWCNT bundles. The hybrid material has been characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and Raman spectroscopy. Characteristic optical properties of the hybrid structure have been identified through UV-Vis and photoluminescence (PL) spectroscopy.
PHOTOACOUSTICS AND MAGNETIC STUDIES OF Fe3O4 NANOPARTICLES
Authors: RAJKUMAR N. , UMAMAHAESWARI D. , RAMACHANDRAN K.
Published: November 2010

Fe3O4 nanoparticles of size 10 and 12 nm were synthesized by chemical reduction method and characterized for their structural, optical, thermal and magnetic properties at room temperature. Photoacoustic analysis shows a reduction in thermal conductivity atleast by one order from the bulk but within the nanoregime, thermal conductivity increases with decreasing particle size. VSM measurements indicate superparamagnetism in Fe3O4 nanoparticles.
ELECTROCHEMICAL NANOSTRUCTURING OF SEMICONDUCTOR WAFERS BY CAPILLARY-FORCE-ASSISTED METHOD
Authors: TIMOSHENKO VICTOR YU. , GONCHAR KYRILL A. , MASLOVA NATALIA E. , TAURBAYEV YERZHAN T. , TAURBAYEV TOKHTAR I.
Published: November 2010

Wafers of crystalline silicon (c-Si) and compound semiconductors (GaP, GaAs) were nanostructured by using the electrochemical etching in specially designed cells with two or more electrodes spaced at 100–500 μm distances, which allowed keeping the electrolyte due to capillary forces. Investigations by means of atomic force microscopy and optical spectroscopy revealed nanoporous and nanocrystalline structure of the prepared samples. The employed capillary-force-assisted method is promising for preparation of thin layers of nanostructured semiconductors with desired optical properties having advantages of cost saving, quickness and flexibility in the electrical contact arrangements versus conventional electrochemical etching methods.
ONLINE SURFACE MEASUREMENT WITH DIGITAL SHACK–HARTMANN WAVEFRONT SENSOR
Authors: YIN XIAOMING , ZHAO LIPING , LI XIANG , FANG ZHONGPING
Published: November 2010

Shack–Hartmann wavefront sensor splits the incident wavefront into many subsections and transfers the distorted wavefront detection into the centroid measurement. The accuracy of the centroid measurement determines the accuracy of the SHWS. In this paper, we have presented an automatic centroid measurement method based on the image processing technology for practical applications of the digital SHWS in surface profile measurement. The method can detect the centroid of each focal spot accurately and robustly by eliminating the influences of various noises. Based on this centroid detection method, we have developed a digital SHWS system which can automatically detect centroids of focal spots, reconstruct the wavefront, and measure the 3D profile of the surface. The experimental results demonstrate that the system has good accuracy, repeatability and compatibility to optical misalignment. The system is suitable for online applications of surface measurement.
REAL TIME VISUALIZATION OF SURFACTANT EFFECTS ON COLLOIDAL SELF-ASSEMBLY
Authors: ZHAO Q. , NG E. , KANG H. K. , YIP C. H. , HARTONO M. R. , WONG C. C.
Published: November 2010

Patterned substrates, coupled with surfactant addition, offer a way to exercise more control in the convective self-assembly of colloidal nanospheres. In this work, we investigated the surfactant effects on dynamic colloidal self-assembly during evaporation in a sessile drop. The real time video monitoring revealed that the surfactant plays a dominating role to determine the wetting angle of the colloidal suspension in a sessile drop. Meanwhile, surfactant also had great influence on the cluster formation during assembly process and the final lattice structure.
TEMPERATURE-DEPENDENT MODIFICATIONS OF Ag/SiO2/p-Si SCHOTTKY CONTACTS FORMED AT 20 K
Authors: ALI A. , YASAR M. , NASIM F. , BHATTI A. S.
Published: November 2010

The Schottky contacts of Ag/SiO2 /p- Si were fabricated by thermal evaporation at 20 K. The effect of annealing temperatures varying from 373 to 773 K on the morphology and electrical properties of these contacts was investigated. The average grain size increased while the density of grains decreased with increasing temperature. Ideality factor initially observed was as high as 4.15 with a low barrier height of 0.04 eV for contact grown at 20 K. Annealing resulted in shift of ideality factor and barrier height towards ideal behavior. Thus, it is demonstrated that Ag/SiO2 /p- Si contacts grown at low temperature can be modified by annealing.
HAND POSTURE AND FACE RECOGNITION USING A FUZZY-ROUGH APPROACH
Authors: KUMAR P. PRAMOD , VADAKKEPAT PRAHLAD , LOH AI POH
Published: November 2010

A novel algorithm based on fuzzy-rough sets is proposed for the recognition of hand postures and face. Features of the image are extracted using the computational model of the ventral stream of visual cortex. The recognition algorithm translates each quantitative value of the feature into fuzzy sets of linguistic terms using membership functions. The membership functions are formed by the fuzzy partitioning of the feature space into fuzzy equivalence classes, using the feature cluster centers generated by the subtractive clustering technique. A rule base generated from the lower and upper approximations of the fuzzy equivalence classes classifies the images through a voting process. Using genetic algorithm, the number of features required for classification is reduced by identifying the predictive image features. The margin of classification, which is a measure of the discriminative power of the classifier, is used to ensure the quality of classification process. The fitness function suggested assists in the feature selection process without compromising on the classification accuracy and margin. The proposed algorithm is tested using two hand posture and three face datasets. The algorithm provided good classification accuracy, at a less computational effort. The selection of relevant features further reduced the computational costs of both feature extraction and classification algorithms, which makes it suitable for real-time applications. The performance of the proposed algorithm is compared with that of support vector machines.
DESIGN OF A POSITION AND FORCE CONTROL SCHEME FOR 6RSS PARALLEL ROBOTS AND ITS APPLICATION IN CHEWING ROBOTS
Authors: HUANG L. , XU W. L. , TORRANCE J. , BRONLUND J. E.
Published: November 2010

Parallel robots have been found in many applications where the work requirements are beyond the capabilities of serial robots. For example, mouth movements of chewing foods can be generated by a parallel robot. In this paper, the issue of dynamic position and force control of a chewing robot with a 6RSS mechanism is addressed. The kinematic and dynamic models of a generic 6RSS robot are developed and are then simplified considering the special features of a practical chewing robot and the requirements of controller design. An impedance control scheme is proposed to achieve the position and force control of the robot. A detailed description on the steps to implement the controller is also presented.
A NOVEL SWEPT LASER SOURCE BASED ON COMBINED TUNABLE FILTERS FOR OCT
Authors: CHEN MINGHUI , DING ZHIHUA , WANG LING , WU TONG , TAO YUANHAO
Published: November 2010

A novel broad tunable bandwidth and narrow instantaneous line-width linear swept laser source using combined tunable filters working at 1,300 nm center wavelength is proposed. The combined filters consist of a fiber Fabry–Perot tunable filter and a tunable filter based on diffractive grating with scanning polygon mirror. In contrast to traditional method using single tunable filter, the trade-off between bandwidth and instantaneous line-width is alleviated. Parallel implementation of two semiconductor optical amplifiers with different wavelength range is adopted in the laser resonator for broadband light amplification. The Fourier domain mode locking swept laser source with combined tunable filters offers broadband tunable range with narrow instantaneous line-width, which is especially benefiting for high-quality optical frequency domain imaging. The proposed Fourier domain mode locking swept laser source provides a tuning range of 160 nm with instantaneous line-width of about 0.01 nm at sweeping rate of 15 kHz, a finesse of 16,000 is thus achieved.
Retinal Ganglion Cell Layer of the Caspian Seal Pusa caspica: Topography and Localization of the High-Resolution Area
Authors: Mass Alla M. , Supin A.Y.
Published: November 2010

Retinal topography, cell density and sizes of ganglion cells in the Caspian seal (Pusa caspica) were analyzed in retinal whole mounts stained with cresyl-violet. The topographic distribution of ganglion cells displayed an area of high cell density located in the temporal quadrant of the retina and was similar to the area centralis of terrestrial carnivores. It extended nasally, above the optic disk, as a streak of increased cell density. In different whole mounts, the peak cell density in the high-density area ranged from 1,684 to 1,844 cells/mm2 (mean 1,773 cells/mm2). The cell density data predict a retinal resolution of around 8.5 cycles/degree in water. A distinctive feature of the Caspian seal’s retina is the large size of ganglion cells and the low cell density compared to terrestrial mammals. The ganglion cell diameter ranged from 10 to 58 µm. Cell size histograms featured bimodal patterns with groups of small and large ganglion cells. The large cells appeared similar to α-cells of terrestrial mammals and constituted 7% of the total ganglion cell population.
Extensive Changes in the Expression of the Opioid Genes between Humans and Chimpanzees
Authors: Cruz-Gordillo Peter , Fedrigo Olivier , Wray Gregory A. , Babbitt Courtney C.
Published: November 2010

The various means by which the body perceives, transmits, and resolves the experiences of pain and nociception are mediated by a host of molecules, including neuropeptides within the opioid gene signaling pathway. The peptide ligands and receptors encoded by this group of genes have been linked to behavioral disorders as well as a number of psychiatric affective disorders. Our aim was to explore the recent evolutionary history of these two gene families by taking a comparative genomics approach, specifically through a comparison between humans and chimpanzees. Our analyses indicate differential expression of these genes between the two species, more than expected based on genome-wide comparisons, indicating that differential expression is pervasive among the opioid genes. Of the 8 family members, three genes showed significant expression differences (PENK, PNOC, and OPRL1), with two others marginally significant (OPRM1 and OPRD1). Accelerated substitution rates along human and chimpanzee lineages within the putative regulatory regions of OPRM1, POMC, and PDYN between the human and chimpanzee branches are consistent with positive selection. Collectively, these results suggest that there may have been a selective advantage to modulating the expression of the opioid genes in humans compared with our closest living relatives. Information about the cognitive roles mediated by these genes in humans may help to elucidate the trait consequences of these putatively adaptive expression changes.
Comparing Different Methods to Assess Erosive Lesion Depths and Progression in vitro
Authors: Stenhagen K.R. , Hove L.H. , Holme B. , Taxt-Lamolle S. , Tveit A.B.
Published: November 2010

The aim of this study was to compare the precision and accuracy of 5 different methods applied to assess surface substance loss or changes in surface microhardness (SMH) on the same enamel surfaces after repeated acid exposures. Ground specimens from human molars were exposed to 0.01 M HCl (pH 2.2) for 6 min × 2 and measurements performed 3 times to estimate precision. The accuracies (systematic errors) were calculated against the manufacturer’s calibration standard. Lesion depth progression was from 94 to 110%, related to repeated acid exposure. The precisions/accuracies were: WLI (white light interferometry), 0.5/0.4%; SP (stylus profilometry), 4.7/0.7%; OP (optical profilometry), 1.4/12%; AAS (atomic absorption spectroscopy), 0.4/17% (measured calcium loss was converted to lesion depth). The correlation between WLI and SP was R2 = 0.98, and between WLI and OP it was R2 = 0.85. SMH gave information on qualitative changes of the surface (precision: 5.5%, accuracy: 4.0%). WLI performed best in precision and accuracy, but SP, OP and AAS are all relevant methods for analysing lesion depths and progression, SMH seems suitable for analysing minor changes in surface enamel only.
Health System Implications of Direct-to-Consumer Personal Genome Testing
Authors: McGuire Amy L. , Burke Wylie
Published: November 2010

Direct-to-consumer personal genome testing is now widely available to consumers. Proponents argue that knowledge is power but critics worry about consumer safety and potential harms resulting from misinterpretation of test information. In this article, we consider the health system implications of direct-to-consumer personal genome testing, focusing on issues of accountability, both corporate and professional.
European Ancestry as a Risk Factor for Atrial Fibrillation in African Americans
Authors: Marcus Gregory M. , Alonso Alvaro , Peralta Carmen A. , Lettre Guillaume , Vittinghoff Eric , Lubitz Steven A. , Fox Ervin R. , Levitzky Yamini S. , Mehra Reena , Kerr Kathleen F. , Deo Rajat , Sotoodehnia Nona , Akylbekova Meggie , Ellinor Patrick T. , Paltoo Dina N. , Soliman Elsayed Z. , Benjamin Emelia J. , Heckbert Susan R. ,   for the Candidate-Gene Association Resource (CARe) Study
Published: November 2010

Background—

Despite a higher burden of standard atrial fibrillation (AF) risk factors, African Americans have a lower risk of AF than whites. It is unknown whether the higher risk is due to genetic or environmental factors. Because African Americans have varying degrees of European ancestry, we sought to test the hypothesis that European ancestry is an independent risk factor for AF.

Methods and Results—

We studied whites (n=4543) and African Americans (n=822) in the Cardiovascular Health Study (CHS) and whites (n=10 902) and African Americans (n=3517) in the Atherosclerosis Risk in Communities (ARIC) Study (n=3517). Percent European ancestry in African Americans was estimated with 1747 ancestry informative markers from the Illumina custom ITMAT-Broad-CARe array. Among African Americans without baseline AF, 120 of 804 CHS participants and 181 of 3517 ARIC participants developed incident AF. A meta-analysis from the 2 studies revealed that every 10% increase in European ancestry increased the risk of AF by 13% (hazard ratio, 1.13; 95% confidence interval, 1.03 to 1.23;
P
=0.007). After adjustment for potential confounders, European ancestry remained a predictor of incident AF in each cohort alone, with a combined estimated hazard ratio for each 10% increase in European ancestry of 1.17 (95% confidence interval, 1.07 to 1.29;
P
=0.001). A second analysis using 3192 ancestry informative markers from a genome-wide Affymetrix 6.0 array in ARIC African Americans yielded similar results.

Conclusions—

European ancestry predicted risk of incident AF. Our study suggests that investigating genetic variants contributing to differential AF risk in individuals of African versus European ancestry will be informative.
Stepping Back from the Third World: Soviet Policy toward the United Arab Republic, 1965–1967
Authors: Laron Guy
Published: November 2010

This article shows that for two years prior to the June 1967 Six-Day Mideast War, Soviet-Egyptian relations had begun to fray because the Soviet Union wanted to loosen its ties with radical regimes in the Third World, including Gamal Abdel Nasser's Egypt. Soviet leaders urged Nasser to reform the Egyptian economy, decrease Egypt's military involvement in Yemen, and allow the Soviet Navy unfettered access to Egyptian ports. But like numerous other small powers during the Cold War, Egypt was able to fend off the pressure of its superpower ally. In May 1967, when Egypt unilaterally decided to bring its forces into the Sinai, Soviet leaders were divided over how to respond to the crisis that engulfed the Middle East. In the end, the more cautious faction in Moscow prevailed, and the Soviet government continued to be wary of becoming embroiled in conflicts initiated by radical Third World regimes.
Delusion or Reality? Secret Hungarian Diplomacy during the Vietnam War
Authors: Szőke Zoltán
Published: November 2010

This article builds on work published in the Journal of Cold War Studies in 2003 by James G. Hershberg, who presented newly released archival evidence from Budapest and Warsaw concerning the role that Hungary and Poland played as intermediaries between Washington and Hanoi during the 37-day pause in the U.S. bombing campaign against North Vietnam in December 1965 and January 1966. The evidence presented here, drawing on unpublished Hungarian (and partly unpublished U.S.) archival sources, refines some of Hershberg's conclusions and sheds new light on Budapest's mediatory attempt as well as Hungary's role in the Vietnam conflict. The article provides the first critical appraisal of Delusion and Reality, the 1978 book by János Radványi, Hungary's former chargé d'affaires in Washington. For 25 years, Radványi's book constituted the only available Soviet-bloc account of the secret Communist peace efforts during the Vietnam War.
Cold War “Bridge-Building”: U.S. Exchange Exhibits and Their Reception in the Soviet Union, 1959–1967
Authors: Tolvaisas Tomas
Published: November 2010

Following the presentation of the American National Exhibition in Moscow in 1959, nine exhibits organized by the United States Information Agency traveled in the Soviet Union from 1961 to 1967. This article discusses the aims, preparation, content, and reception of these exhibits, which attracted more than five million visitors and provoked diverse reactions. The exhibitions and their guides served as a unique form of communication with Soviet citizens, informing them about U.S. achievements and freedoms and the American way of life. The initiatives offset Soviet Communist propaganda, advanced popular understanding of the United States, and promoted popular goodwill toward Americans. The low-key interactions between the guides and the visitors shed valuable light on the mindset and experiences of ordinary citizens in the USSR, who were a major target audience of these exhibitions, and also, more broadly, on U.S. public diplomacy during the Cold War.
The United States and the Kurds: A Cold War Story
Authors: Little Douglas
Published: November 2010

In a prolonged quest for independence after 1945, Kurdish nationalists reportedly sought help from U.S. officials who viewed the Kurdish issue through a Cold War prism and who regarded the Kurds as querulous mountain tribes useful primarily in keeping the Soviet Union and its Arab clients off balance. Recently declassified documents shed new light on three key episodes in this story: first, the secret encouragement provided by Washington to Kurds opposed to Iraq's Abdul Karim Qassim, who tilted toward Moscow after seizing power in 1958; second, the covert action launched by Richard Nixon and Henry Kissinger in Iraqi Kurdistan after Saddam Hussein allied himself with the USSR in 1972; and third, the half-hearted U.S. attempts to foment regime change in Iraq in the early 1990s. In each case, the U.S. government stirred up anti-Arab resentments among the Kurds, helped ignite an insurrection, and then pulled the plug when events spiraled out of control. U.S. duplicity plus Kurdish factionalism equaled tragedy in the mountains of Kurdistan.
Perception-Based Data Reduction for Haptic Force-Feedback Signals Using Velocity-Adaptive Deadbands
Authors: Kammerl Julius , Vittorias Iason , Nitsch Verena , Steinbach Eckehard , Hirche Sandra
Published: November 2010

In telepresence and teleaction (TPTA) systems, the transmission of haptic signals puts high demands on the applied signal processing and communication procedures. When running a TPTA session across a packet-based communication network (e.g., the Internet), minimizing the end-to-end delay results in packet rates of up to the applied sampling rate of the local control loops at the human system interface and the teleoperator. The perceptual deadband data reduction approach for haptic signals successfully addresses the challenge of high packet rates in networked TPTA systems and satisfies the strict delay constraints. In this paper, we extend the underlying perceptual model of the deadband approach by incorporating psychophysical findings on human force-feedback discrimination during operators' relative hand movements. By applying velocity-dependent perception thresholds to the deadband approach, we observe further improvement in efficiency and performance due to improved adaption to human haptic perception thresholds. The psychophysical experiments conducted reveal improved data reduction performance of our proposed haptic perceptual coding scheme without impairing the user experience. Our results show a high data reduction ability of up to 96% without affecting system transparency or the operator's task performance.
Telepresence in Industrial Applications: Implementation Issues for Assembly Tasks
Authors: Radi Marwan , Nitsch Verena
Published: November 2010

In contrast to automated production, human intelligence is deemed necessary for successful execution of assembly tasks that are difficult or expensive to automate in small and medium lots. However, human ability is hindered in some cases by physical barriers such as miniaturization or in contrast, very heavy components. Telepresence technology can be considered a solution for performing a wide variety of assembly tasks where human intelligence and haptic sense are needed. This work highlights several issues involved in deploying industrial telepresence systems to manipulate and assemble microparts as well as heavy objects. Two sets of experiments are conducted to investigate telepresence related aspects in an industrial setting. The first experiment evaluates the usefulness of haptic feedback for a human operator in a standard pick-and-place task. Three operation modes were considered: visual feedback, force feedback, and force assistance (realized as vibration). In the second experiment, two different guidance strategies for the teleoperator were tested. The comparison between a position and a velocity scheme in terms of task completion time and subjective preferences is presented.
Time Domain Passivity Control for Position-Position Teleoperation Architectures
Authors: Artigas Jordi , Ryu Jee-Hwan , Preusche Carsten
Published: November 2010

This article presents a method for passivating the communication channel of a symmetric position-position teleoperation architecture on the time domain. The time domain passivity control approach has recently gained appeal in the context of timedelayed teleoperation because passivity is not established as a design constraint, which often forces conservative rules, but rather as a property which the system must preserve during operation. Since passivity is a network property, the first design rule within this framework is to represent consistent and comprehensible circuit (i.e., network) representations of the mechanical teleoperation system. In particular, the energetic behavior of these networks is interesting because it allows straightforward conclusions about system stability. By means of so-called passivity observers (PO) and passivity controllers (PC) (Hannaford & Ryu, 2001), the energetic response of a delayed communication channel is captured and modulated over time so that the network in question never becomes nonpassive. The case analyzed in this paper tackles a communication channel that conveys position data back and forth. This type of channel does not offer intuitive network representation since only flows are actually being transmitted. Although energy clearly travels from one side to the other, port power identification, as defined by the correlated pair flow and effort, is not evident. This work first investigates how this kind of channel can be represented by means of circuit networks even with the lack of physical effort being transmitted through the channel, and identifies which networks are susceptible to become nonpassive due to the channel characteristics (i.e., time delay, discretization or package loss). Once achieved, a distributed control structure is presented based on a PC series that keeps the system at the verge of passivity (and therefore stability) independent from the channel properties. The results obtained by the simulation and by experiment sustain the presented approach.
Teaching Urban Sociology and Urban Sustainability on Two Feet, Two Wheels, and in Three Cities
Authors: Christiansen Lars , Fischer Nancy
Published: November 2010

The authors describe their experiences teaching Sustainable Cities in North America, a course on both urban sociology and urban sustainability. This course brought students to Portland, Oregon, and Vancouver, British Columbia, and then compared those cities with Minneapolis, Minnesota, on various dimensions of urban sustainability. After connecting this course to existing sociological scholarship on teaching urban sociology and travel–study abroad, the authors describe their course “in action”: what they did, why it was (and was not) “green,” and an assessment of the course, including postcourse actions and institutional changes that the course inspired. The authors conclude with a call for more “green” sociology courses and travel–study abroad courses as innovative and exciting ways to teach sociology and to further the discipline’s commitment to ethical environmental actions.
Learning to coordinate in complex networks
Authors: Van Segbroeck Sven , de Jong Steven , Nowé Ann , Santos Francisco C , Lenaerts Tom
Published: November 2010

Designing an adaptive multi-agent system often requires the specification of interaction patterns between the different agents. To date, it remains unclear to what extent such interaction patterns influence the dynamics of the learning mechanisms inherent to each agent in the system. Here, we address this fundamental problem, both analytically and via computer simulations, examining networks of agents that engage in stag-hunt games with their neighbors and thereby learn to coordinate their actions. We show that the specific network topology does not affect the game strategy the agents learn on average. Yet, network features such as heterogeneity and clustering effectively determine how this average game behavior arises and how it manifests itself. Network heterogeneity induces variation in learning speed, whereas network clustering results in the emergence of clusters of agents with similar strategies. Such clusters also form when the network structure is not predefined, but shaped by the agents themselves. In that case, the strategy of an agent may become correlated with that of its neighbors on the one hand, and with its degree on the other hand. Here, we show that the presence of such correlations drastically changes the overall learning behavior of the agents. As such, our work provides a clear-cut picture of the learning dynamics associated with networks of agents trying to optimally coordinate their actions.
Arbitrariness of models for augmented and coarse data, with emphasis on incomplete data and random effects models
Authors: Verbeke Geert , Molenberghs Geert
Published: November 2010

Statistical models often extend beyond the data available. First, in coarse data, what is actually observed is less detailed than what might be, owing to incompleteness, censoring, grouping, or a combination thereof. Second, in augmented data, the observed data are hypothetically supplemented with random effects, latent variables/classes, or component membership in mixture distributions. The two settings together will be referred to as enriched data. Reasons for modelling enriched data encompass mathematical and computational convenience, advantages in interpretation, and substantive plausibility. Models for enriched data combine evidence coming from empirical data with unverifiable model components, resting entirely on assumptions.

This has acute consequences for enriched data, but knowledge about this issue is somewhat scattered. We provide a unified framework for enriched data and show, generally and with focus on incomplete-data models and random-effects models on the other hand, that to any given model an entire class of models can be assigned, with all of its members producing the same fit to the observed data but arbitrary regarding the unobservable parts of the enriched data. The concepts developed are illustrated using a clinical trial in toenail dermatophyte onychomycosis and a developmental toxicity study conducted in mice.
Juvenile Justice Reform and Policy Convergence in the New Vietnam
Authors: Cox Pamela
Published: November 2010

This article analyses juvenile justice reform in Vietnam and suggests how this connects with key transformations in wider Vietnamese cultures of control. It offers a grounded investigation of themes raised in recent discussions of policy transfer in the global criminal justice field. It concurs with others that global processes of policy convergence have their local limits, using Vietnamese examples to illustrate where this convergence comes about in practice and where it does not. It explores efforts to professionalize existing community justice practices through a discussion of perceived needs for ‘training’ and for the expansion of ‘counselling’. In doing so, it aims to show how justice practices that might be called ‘neo-welfarist’ are emerging in one of East Asia’s most remarkable political hybrids — the new Vietnam — a communist state that has embraced economic liberalism and, in the process, is creating a new kind of ‘social’ sphere.
Locking Up for the Best Interests of the Child — Some Preliminary Remarks on ‘Special Care’
Authors: Pösö Tarja , Kitinoja Manu , Kekoni Taru
Published: November 2010

The article studies the practice of one special form of closed accommodation: special care. The term suggests that this is a welfare-oriented response to norm-breaking behaviour of young people. The empirical example comes from Finland, where special care is defined as restrictive activity under the Child Welfare Act and aimed at, among other things, interrupting a vicious circle of crime in young people for the best interests of the child. A contradictory picture is drawn of special care. The article suggests that the contradictions should be understood — but not necessarily accepted — within the social context in which the institutional placements take place.
Establishing a Community-Based Lung Cancer Multidisciplinary Clinic As Part of a Large Integrated Health Care System: Aurora Health Care
Authors: Bjegovich-Weidman Marija , Haid Max , Kumar Santhosh , Huibregtse Carol , McDonald Jean , Krishnan Santosh
Published: November 2010

This Lung Cancer Multidisciplinary Clinic (MDC) included medical and radiation oncologists, a thoracic surgeon, and a pulmonologist and met every third week. Establishment of the clinic resulted in improvements in quality of care, patient satisfaction, and patient retention.
Team Dynamics, Decision Making, and Attitudes Toward Multidisciplinary Cancer Meetings: Health Professionals' Perspectives
Authors: Devitt Bianca , Philip Jennifer , McLachlan Sue-Anne
Published: November 2010

As the complexity of cancer treatment increases so too has the need for coordination between health care professionals. Multidisciplinary meetings are a useful tool in treating patients with cancer and are shown to improve survival and adherence to evidence based-guidelines.