bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolement et identification de Clostridium tetani dans le sol des Cantons de l'Est de la province de Québec
Authors: Beland S. , Rossier E.
Published: February 2010

The analysis of 600 samples of topsoil of the Eastern Townships region shows that Clostridium tetani is present in 53% of those specimens. The high percentage of positivity shows the sensitivity of the technique used and the biochemical analysis of the numerous strains brings out a few characters that are different from those reported in the literature.
Characteristics of a Vibrio parahaemolyticus bacteriophage isolated from Atlantic coast sediment
Authors: Sklarow S. S. , Colwell R. R. , Chapman G. B. , Zane S. F.
Published: February 2010

A DNA-containing bacteriophage morphologically similar to the T phages and specific for Vibrio parahaemolyticus was found in sediment samples from the Atlantic coastal regions.
Isolation of mutants of Bacillus stearothermophilus blocked in catabolic function
Authors: Rowe J. J. , Goldberg I. D. , Amelunxen R. E.
Published: February 2010

A method is presented for the isolation of mutants of the obligate thermophile Bacillus stearothermophilus. Mutants blocked in fumarase, aconitase, and alcohol dehydrogenase have been isolated by the procedures described. The availability of thermophilic mutants provides a genetic approach for studying the phenomenon of thermophily.
SUBWORD OCCURRENCES, PARIKH MATRICES AND LYNDON IMAGES
Authors: SALOMAA ARTO , YU SHENG
Published: February 2010

We investigate the number of occurrences of a word u as a (scattered) subword of a word w. The notion of a Parikh matrix, recently introduced, is a basic tool in this investigation. In general, several words are associated with a Parikh matrix. The ambiguity can be resolved by associating a unique word called the Lyndon image to each Parikh matrix. In this paper we will investigate properties of Lyndon images and the corresponding questions of ambiguity. We give an exhaustive characterization in the case of a binary alphabet. Our main results in the general case deal with the comparison of unambiguous words and Lyndon images, algorithms for constructing Lyndon images, as well as classes of words with the same Parikh matrix, obtained by circular variance.
TOWARD A RELATIVITY OF DARK MATTER RODS AND CLOCKS
Authors: AHLUWALIA D. V.
Published: February 2010

In the absence of dark matter, the dynamical and kinematical interpretations of the special-relativistic space–time have been and still are the topic of philosophic debate, which, whilst fertile, is by and large of little predictive power. This changes dramatically if the debate includes a dark matter candidate in a "nontrivial" extension of the standard model. Here I argue that rods and clocks made out of dark matter may not reveal the same underlying algebraic structure as the rods and clocks made out of standard model particles. For the sake of concreteness I here exemplify the argument by looking at a particular dark matter candidate called Elko. Inevitably, one is led to the conclusion that gravity within the dark sector, and at the interface between dark matter and standard model matter, may deviate from the canonical general-relativistic predictions. For Elko dark matter such effects will be of second order, in the sense that they will depend only on the angular momentum and spin of the gravitational environment.
INTERFEROMETRIC DETECTION OF GRAVITATIONAL WAVES: THE DEFINITIVE TEST FOR GENERAL RELATIVITY
Authors: CORDA CHRISTIAN
Published: February 2010

Even though Einstein's general relativity has achieved great success and passed a lot of experimental tests, it has also shown some shortcomings and flaws which today prompt theorists to ask if it is the definitive theory of gravity. In this essay we show that if advanced projects on the detection of gravitational waves (GWs) improve their sensitivity, allowing us to perform a GW astronomy then accurate angle- and frequency-dependent response functions of interferometers for GWs arising from various theories of gravity, i.e. general relativity and extended theories of gravity, will be the definitive test for general relativity. The papers mentioned in this essay were the world's most-cited in 2007 of the Astroparticle Publication Review of ASPERA with 13 citations.
TIME, VACUUM ENERGY, AND THE COSMOLOGICAL CONSTANT
Authors: HUSAIN VIQAR
Published: February 2010

We describe a link between the cosmological constant problem and the problem of time in quantum gravity. This arises from examining the relationship between the cosmological constant and vacuum energy in light of nonperturbative formulations of quantum gravity.
DARK ENERGY: THE ABSOLUTE ELECTRIC POTENTIAL OF THE UNIVERSE
Authors: JIMÉNEZ JOSE BELTRÁN , MAROTO ANTONIO L.
Published: February 2010

Is there an absolute cosmic electric potential? The recent discovery of the accelerated expansion of the universe could be indicating that this is certainly the case. In this essay we show that the consistency of the covariant and gauge-invariant theory of electromagnetism is truly questionable when considered on cosmological scales. Out of the four components of the electromagnetic field, Maxwell's theory contains only two physical degrees of freedom. However, in the presence of gravity, one of the "unphysical" states cannot be consistently eliminated, thus becoming real. This third polarization state is completely decoupled from charged matter, but can be excited gravitationally, thus breaking gauge invariance. On large scales the new state can be seen as a homogeneous cosmic electric potential, whose energy density behaves as a cosmological constant.
DOES GRAVITY PREFER THE POINCARÉ DODECAHEDRAL SPACE?
Authors: ROUKEMA BOUDEWIJN F.
Published: February 2010

The missing fluctuations problem in cosmic microwave background observations is naturally explained by well-proportioned small universe models. Among these models, the Poincaré dodecahedral space is empirically favored. Does gravity favor this space? The residual gravity effect is the residual acceleration induced by weak limit gravity from multiple topological images of a massive object on a nearby negligible mass test object. At the present epoch, the residual gravity effect is about a million times weaker in three of the well-proportioned spaces than in ill-proportioned spaces. However, in the Poincaré space, the effect is 10,000 times weaker still, i.e. the Poincaré space is about 10,000 times "better-balanced" than ill-proportioned spaces. Both observations and weak limit dynamics select the Poincaré space to be special.
AN ANSWER TO THE MAIN BLACK HOLE PATHOLOGY: FORMING NONSINGULAR BLACK HOLES FROM DUST COLLAPSE
Authors: MAIER R. , DAMIÃO SOARES I.
Published: February 2010

The dynamics of gravitational collapse is examined in the realm of string-based formalism of D-branes which encompasses general relativity as a low energy limit. A complete analytical solution is given to the spherically symmetric collapse of a pure dust star, including its matching with a corrected Schwarzschild exterior space–time. The collapse forms a black hole (an exterior event horizon) enclosing not a singularity but perpetually bouncing matter in the infinite chain of space–time maximal analytical extensions inside the outer event horizon. This chain of analytical extensions has a structure analogous to that of the Reissner–Nordstrom solution. The interior trapped bouncing matter has the possibility of being expelled by disruptive nonlinear resonance mechanisms.
GRAVITY HEATS THE UNIVERSE
Authors: MOSS ADAM , SCOTT DOUGLAS
Published: February 2010

Structures in the Universe grew through gravitational instability from very smooth initial conditions. Energy conservation requires that the growing negative potential energy of these structures be balanced by an increase in kinetic energy. A fraction of this is converted into heat in the collisional gas of the intergalactic medium. Using a toy model of gravitational heating, we attempt to link the growth of structure in the Universe with the average temperature of this gas. We find that the gas is rapidly heated from collapsing structures at around z ~ 10, reaching a temperature > 106 K today, depending on some assumptions of our simplified model. Before that there was a cold era from z ~ 100 to ~10 in which the matter temperature was below that of the cosmic microwave background.
DIRECT DETECTION OF THE PRIMORDIAL INFLATIONARY GRAVITATIONAL WAVES
Authors: NI WEI-TOU
Published: February 2010

Inflationary cosmology is successful in explaining a number of outstanding cosmological issues, including the flatness, the horizon and the relic issues. More spectacular is the experimental confirmation of the structure as arising from the inflationary quantum fluctuations. However, the physics in the inflationary era is unclear. Polarization observations of cosmic microwave background (CMB) missions may detect the tensor mode effects of inflationary gravitational waves (GWs) and give an energy scale of inflation. To probe the inflationary physics, direct observation of GWs generated in the inflationary era is needed. In this essay, we advocate that the direct observation of these GWs with sensitivity down to Ω GW ~ 10-23 is possible using the presently projected technology development if the foreground could be separated.
ENTROPY DENSITY OF SPACE–TIME AND GRAVITY: A CONCEPTUAL SYNTHESIS
Authors: PADMANABHAN T.
Published: February 2010

I show that combining the principle of equivalence and the principle of general covariance with the known properties of local Rindler horizons, perceived by accelerated observers, leads to the following inescapable conclusion: The field equations describing gravity in any diffeomorphism-invariant theory must have a thermodynamic interpretation. This synthesis of quantum theory, thermodynamics and gravity shows that the gravitational dynamics can be interpreted completely in terms of entropy balance between matter and space–time. This idea has far-reaching implications for the microstructure of space–time and quantum gravity.
BEND IT LIKE EINSTEIN: GRAVITATIONAL DEFLECTION OF CLASSICAL, QUANTUM AND EXOTIC LIGHT
Authors: UNNIKRISHNAN C. S. , GILLIES G. T.
Published: February 2010

Gravitational bending of light is a spectacular prediction of Einstein's general relativity, tested and observed in numerous situations. We examine the fine structure of gravitational bending in new light to obtain insights pertaining to some deep links between gravity and quantum mechanics. The new results include quantum-theoretical interpretation of part of the light bending, making a good case for gravity encompassing wave–particle duality, perhaps a new insight for quantum gravity itself. We reiterate the mutual compatibility of the equivalence principle and quantum dynamics in a simple proof. Finally, we address certain unresolved issues regarding the gravitational bending of ultraslow light and tunneling photons in the context of experiments that might pose fresh challenges for the interface of the two century-old theories.
VIDEO IMAGE CLUSTERING BASED ON HUMAN FACE AND SHIRT COLOR
Authors: HOSSAIN MD. SHAFAEAT , RAHMAN KHANDAKER ABIR , HASANUZZAMAN MD. , BHUYIAN M. A. , UENO H.
Published: February 2010

This paper proposes a novel video image clustering method based on human face and shirt color. Clustering has been performed in unsupervised manner where no prior knowledge about the input video clip is required. For face detection, multi-resolution templates based pattern matching method has been used. We have experimented on 11 video clips of various durations in order to evaluate the performance of the proposed system. The ability of the system to generate a meaningful number of clusters that exist in the input video clip is definitely well. The performance of the system with respect to precision and recall rate is also highly satisfactory.
CONSTRUCTING SURFACE FEATURES THROUGH DEFORMATION
Authors: WANG XIAOPING , LIU SHENGLAN , ZHANG LIYAN
Published: February 2010

A frequent problem in computer aided mechanical design is the construction of arbitrarily-shaped ribs and beads on surfaces, to increase their rigidity or for aesthetic reasons. We improve upon a previous mathematical approach for defining such ribs and beads, based on using so-called extension functions to define a deformation matrix, which is then applied to the underlying shape. Our improvements offer important practical advantages: firstly, by use of cosine extension functions, we get a greater control over, and flexibility of, rib shape, including the possibility of repeating ribs; secondly, we can directly control the spine curves. We give experimental results to demonstrate that the method is simple and intuitive, has low computational cost, and is potentially useful for computer aided design, computer graphics and other applications.
FRAGMENTED PARTICLES-BASED ROBUST OBJECT TRACKING WITH FEATURE FUSION
Authors: NIGAM CHHABI , BABU R. VENKATESH , RAJA S. KUMAR , RAMAKRISHNAN K. R.
Published: February 2010

Tracking people or objects across multiple cameras and maintaining a track within a camera is a challenging task in applications such as video surveillance, traffic monitoring, event detection and recognition. Some of the major challenges while tracking a target are illumination/scale changes and partial occlusion. In this paper, we propose a novel tracking framework using particle filter to efficiently track an object within a camera and a blob-based target association scheme for tracking across cameras. The proposed particle filter tracking algorithm uses a fragment-based approach to model the target and track it by fusing color and gradient features. The proposed solution incorporates coarser level spatial information by fragmenting each particle and is shown to be useful for tracking under partial occlusion. A fast yet robust model update is employed to overcome illumination changes. Experimental results show (i) the robustness of the fragment-based tracking approach with respect to illumination/scale change and partial occlusion and (ii) tracking persons across two cameras.
3D SEGMENTATION OF MRI BRAIN USING LEVEL SET AND UNSUPERVISED CLASSIFICATION
Authors: BOUROUIS SAMI , HAMROUNI KAMEL
Published: February 2010

The precise volumetric brain segmentation of normal and pathological MR images is a challenging problem in understanding brain anatomy and functions. The requirement to automate this process is another challenge because manual segmentation is extremely laborious. However, it has been proven to be problematic, both due to the high complexity of anatomical structures as well as their large variability, and due to difficulties caused by the presence of noise and artefacts. This paper describes a fully automatic and accurate method for segmenting normal brain tissues and a semi-automatic procedure for delineating meningiomas tissues. The approach performs the segmentation using a succession operations involving a registration step from known data, a classification step and a segmentation step based on level-set. The role of the registration and the classification is to initialize accurately the active model and to control its evolution. A hybrid region-boundary model using level set technique is also proposed. Our formalism is robust to noise and intensity inhomogeneities, since it exploits the advantage of the combination. It is evaluated on both simulated and real data, and compared with existing segmentation techniques. Qualitative and quantitative results demonstrated its performance and robustness.
COMPARATIVE STUDY OF REACTION RATE CONSTANTS FOR THE NH3 + H → NH2 + H2 REACTION WITH GLOBE DYNAMICS AND TRANSITION STATE THEORIES
Authors: LIPING JU , RUIFENG LU
Published: February 2010

The nine-dimension quasi-classical trajectory (QCT) calculations have been carried out for the title reaction with a global potential energy surface (PES) constructed by Corchado and Espinosa-García (J Chem Phys106:4013, 1997). The detailed dynamics calculations cover the specific collision energies falling in the range of 0.62–3.04 eV, which are sufficient to fit the calculated reactive cross-sections into a barrier-type excitation function and to obtain the thermal rate constants. The present QCT rate constants are in good agreement with the recent quantum dynamics (QD) results, both of which are much lower than that of the previous variational transition state theory (VTST).
THE INFLUENCES OF OXIDATION AND CATIONIZATION ON THE N-GLYCOSIDIC BOND STABILITY OF 8-OXO-2′-DEOXYADENOSINE — A THEORETICAL STUDY
Authors: ZHENG YAN , XUE YING , YAN GUO-SEN
Published: February 2010

This work is an attempt to evaluate theoretically the influences of oxidation and cationization on the N-glycosidic bond stability and the proton and sodium affinities on 8-oxo-2′-deoxyadenosine (8-oxodA) by using the density functional theory (DFT) B3LYP with basis set 6-31++G(d,p). This work shows that the cation attachment to 8-oxodA may modify the equilibrium geometry and bond dissociation. In all modified forms, the length of the N9–C1′ bond in which there is no intramolecular interaction, i.e. O8–H(Na)⋯O4′, increases relative to the neutral system 8-oxodA but that of others decreases. The analysis for the proton and sodium affinity energies indicates that the N1 and N3 atoms are the favorable sites for proton while the N1 atom is the favorable site for Na+. From the dissociation energies of the N-glycosidic bond, it has been found that the homolytic dissociation becomes more difficult upon introducing positive charge in the base ring. In contrast, these systems favor the heterolytic dissociation significantly. The influence is most prominent with the monocation obtained by O8 cationization.
PROTONATION STATES AND CONFORMATIONAL FLEXIBILITY OF THE RED FLUORESCENT PROTEIN CHROMOPHORE
Authors: YAN WEIZHONG , XIE DAIQIAN , ZENG JUN
Published: February 2010

Fluorescent proteins are important reporter molecules widely used in biotechnology and the biological sciences, generally. Their unusual spectrophotometric and fluorescence characteristics are controlled via protonation states of the chromophore, as for green fluorescent proteins (GFPs), and/or via cis–trans isomerization of the chromophore, as for red fluorescent proteins (RFPs). Here, we have performed both quantum mechanical calculations on substituted chromophores and structural comparisons of several RFPs (Rtms5, eqFP611, HcRed, and DsRed) and wild-type GFP. Our results indicate that the chromophore cis and trans isomers are comparably stable, and cis–trans isomerization has only a minor effect on electronic excitation. The chromophore is also found to exist in either the anionic or possibly zwitterionic protonation state. Structural comparisons of RFPs reveal that the conformation of the chromophore within a specific RFP is determined by only a few key residues, which could serve as mutation targets for engineering new fluorescent proteins for novel biotechnological applications.
SOLVENT AND SUBSTITUENT EFFECTS ON THE INTRAMOLECULAR AMIDE HYDROLYSIS OF N-METHYLMALEAMIC ACID
Authors: CAI JUN , WU ZHIJIAN
Published: February 2010

Intramolecular amide hydrolysis of N-methylmaleamic acid is revisited at the B3LYP/6-311G(2df, p)//B3LYP/6-31G(d, p) + ZVPE level, including solvent effects at the CPCM-B3LYP/6-311G(2df, p)//Onsager-B3LYP/6-31G(d, p) + ZPVE level. The concerted reaction mechanism is energetically favorable over stepwise reaction mechanisms in both the gas phase and solution. The calculated reaction barriers are significantly lower in solution than in the gas phase. In addition, it is concluded that the substituents of the four N-methylmaleamic acid derivatives considered herein have a significant effect on the gas-phase reaction barriers but a smaller, or little, effect on the barriers in solution.
THEORETICAL STUDIES ON PHOTOIONIZATION OF GUANINE TAUTOMERS AND INTERCONVERSION OF CATION RADICALS
Authors: ZHANG LIDONG , PAN YANG , QI FEI
Published: February 2010

The G3MP2B3 and P3 methods have been used to calculate the adiabatic and vertical ionization potentials (IPs) of the eight most stable tautomers of guanine. The calculated energy discrepancy between adiabatic and vertical IPs are in good agreement with the changes in geometry from neutral ground state to stable cation radicals. The geometries of imino-oxo form tautomers have no obvious change in the ionization process, which results in less energy discrepancy between vertical and adiabatic IPs. In the ionization process, the geometries of the amino-oxo and amino-hydroxy form tautomers change from nonplanar to planar structures. Hence the amino-oxo and amino-hydroxy form tautomers have larger energy discrepancy between vertical and adiabatic IPs. Further studies on the interconversion of the cation radicals shed further light on the transition process between the cation radicals and the main pathways are the hydrogen migrations and internal rotations of hydroxy (OH) and imino (NH) groups. The barriers of hydrogen rotations are lower than those of hydrogen migrations. Furthermore, the barriers for the hydrogen migrations between two rings are higher, which are about 3.0 eV.
SLIDE AND ROLLING MECHANISMS OF Pt CLUSTERS OUT OF OXYGEN VACANCY REGION ON MgO(100) SURFACE
Authors: SU YANWEI , WANG YAN , CHEN GUANGJU , TRUONG THANH N.
Published: February 2010

We present the theoretical DFT/B3LYP investigations on the cluster nucleation process and moving mechanism for the Pt n (n = 1, 2, 3, 4, 8, and 12) clusters deposited on MgO surface with an embedded cluster model. The structures and energies of the Pt n clusters adsorbed on the perfect and oxygen vacancy MgO surfaces have been calculated. Based on the nucleation of the Pt n clusters on the oxygen vacancy sites of MgO surfaces, the two moving mechanisms of slide and rolling out of the vacancy region have been energetically investigated. The results show that the needed energies per atom moving out of the vacancy region decrease as the cluster sizes increase. Consequently, the big clusters move likely out of the vacancy sites by either slide or rolling model under a certain temperature condition.
STUDY ON THE FREQUENCY CHARACTERISTIC OF PHOTOCHEMICAL OSCILLATORY SYSTEM
Authors: CHEN JING , LU XIAOQUAN
Published: February 2010

As a typical oscillating chemical system, the frequency characteristic of photochemical oscillatory system is analyzed by a reliable oscillation frequency spectrum (OFS) approach. The results show that every periodic signal have a special OFS. The relative standard deviation (RSD) values of frequencies of four relative oscillating signals which belong to photochemical oscillatory system are extracted. They have multi-frequency characteristic. OFS successfully realizes the extraction and calculation of photochemical oscillatory system. OFS can be used to analyze the frequency of complex periodic signal accurately and be suitable for many areas.
Fabrication of High-Power InGaN-Based Light-Emitting Diode Chips on Pyramidally Patterned Sapphire Substrate
Authors: Chen Yi-Ju , Kuo Cheng-Huang , Tun Chun-Ju , Hsu Shih-Chieh , Cheng Yuh-Jen , Liu Cheng-Yi
Published: February 2010

A pyramidal pattern was produced on a c-plane sapphire substrate by a mask-free etching process. Photoluminescence (PL) results show that a GaN-based light-emitting diode (LED) epilayer grown on the pyramidally patterned sapphire substrate has higher epitaxial quality than that grown on a standard flat c-plane sapphire substrate. When the input current is 350 mA, the average light output power of LED chips on the pyramidally patterned sapphire substrate is 37% larger than that of LED chips on a standard c-plane sapphire substrate.
p-Channel Tin Monoxide Thin Film Transistor Fabricated by Vacuum Thermal Evaporation
Authors: Lee Ho-Nyeon , Kim Hyung-Jung , Kim Chang-Kyo
Published: February 2010

By using tin monoxide films, p-channel oxide semiconductor thin film transistors were fabricated with a bottom-gate and bottom-contact structure. A p-type tin monoxide semiconductor thin film was obtained from tin monoxide powder by vacuum thermal evaporation. The as-deposited film showed an amorphous phase, and a polycrystalline tin monoxide was obtained by thermal annealing after the deposition. The hole concentration was on the order of 1017 cm-3, and the Hall mobility was 2.83 cm2 V-1 s-1. The resulting on-current/off-current ratio was more than 102, and the field-effect mobility was approximately 4×10-5 cm2 V-1 s-1.
Semiconducting Electronic Structure of Graphene Adsorbed on Insulating Substrate: Fragility of the Graphene Linear Dispersion Band
Authors: Okada Susumu
Published: February 2010

Using the first-principle total-energy procedure within the framework of the density functional theory, we study the electronic structure of graphene adsorbed on hexagonal boron nitride (h-BN). We find that the linear dispersion band of graphene is fragile and that graphene adsorbed on h-BN exhibits semiconducting properties with a narrow energy gap. The energy gap size depends weakly on the relative atomic arrangement between graphene and the h-BN substrate. Nonuniform electron density on the substrate causes an imbalance in the electrostatic potential between the two sublattices on graphene, leading to their semiconducting property when adsorbed on h-BN.
Structural and Piezoelectric Properties of (1-x)(Na0.5K0.5)NbO3–xBa(Ti0.9Sn0.1)O3 Lead-Free Ceramics
Authors: Cha Yu-Joung , Jeong Young Hun , Lee Young-Jin , Paik Jong-Hoo , Nahm Sahn
Published: February 2010

Lead-free (1-x)(Na0.5K0.5)NbO3–xBa(Ti0.9Sn0.1)O3 ceramics doped with 1 mol % MnO2 [(1-x)NKN–xBTS] were prepared by the conventional solid state method and their structural and piezoelectric properties were investigated. The (1-x)NKN–xBTS ceramics were well synthesized and a dense microstructure was achieved when sintered at 1050 °C for 8 h. The phase transition temperature of the tetragonal–cubic (T
C) peaks became broadened with increasing x, suggesting that a diffuse phase transition was induced and that the ceramic was changed gradually from a normal ferroelectric to a relaxor ferroelectric. The significantly enhanced piezoelectric properties of d
33=256 and k
p=42% were obtained for the 0.94NKN–0.06BTS ceramics.
Induction of Orientational Order through Coupling with Hyper Shear Flow
Authors: Hirano Taichi , Sakai Keiji
Published: February 2010

We directly observed the molecular orientation induced by a hyper shear strain rate of 106 s-1 during the head-on collision of microdroplets. The magnitude of the induced orientational order can be almost equal to that in the nematic state with a spontaneous director. The actual orientational order estimated from microscopic images agreed with the anisotropy determined theoretically from our previous experiments.
Three-Dimensional Tomographic Imaging in Terahertz Region
Authors: Kitahara Hideaki , Tani Masahiko , Hangyo Masanori
Published: February 2010

We have developed a terahertz (THz) tomographic imaging system based on reflective two-dimensional (2D) electro-optic (EO) sampling using a high-speed complementary metal–oxide–semiconductor (CMOS) camera. The inner structures of the sample were identified with the three-dimensional (3D) tomographic image. By using the 2D-THz imaging system, 3D tomographic imaging can be demonstrated within only 3 min.
Measurement of Oscillation Frequency and Spectral Linewidth of Sub-Terahertz InP-Based Resonant Tunneling Diode Oscillators Using Ni–InP Schottky Barrier Diode
Authors: Karashima Koichi , Yokoyama Ryo , Shiraishi Masato , Suzuki Safumi , Aoki Satoshi , Asada Masahiro
Published: February 2010

We report on the measurement of oscillation frequency and spectral linewidth of sub-terahertz GaInAs/AlAs resonant tunneling diode (RTD) oscillators by harmonic heterodyne detection using a Ni–InP Schottky barrier diode integrated with a bow-tie antenna. For an RTD oscillating at 550 GHz and having an output power ≤1 µW, the measured spectral linewidth was at most 10 MHz; this value is in consistent with that obtained theoretically. A narrow linewidth is expected for a device having high output power and Q-factor. We also accurately measured the frequency change with changing bias voltage for the RTD oscillator; this result is useful for frequency modulation and can be applied to the phase-locked loop system.
Transport Properties in a Single Domain of Microscale Sr2RuO4 Single Crystals
Authors: Nobukane Hiroyoshi , Inagaki Katsuhiko , Tsuchiya Satoshi , Asano Yasuhiro , Ichimura Koichi , Yamaya Kazuhiko , Takayanagi Shigeru , Kawasaki Ikuto , Tenya Kenichi , Amitsuka Hiroshi , Tanda Satoshi
Published: February 2010

We report our approach to measuring the transport properties in a single chiral order parameter domain of microscale Sr2RuO4 single crystals. Sr2RuO4 single crystals were grown by the solid-phase reaction. Microscale single crystals were deposited from a dispersed liquid, and selected from the result of the chemical composition and crystallinity of the dispersed crystals. The selected crystals attached to gold electrodes show superconducting properties. We also found the anomalous current–voltage characteristics that show that induced voltage is an even function of bias current.
A New Intercalation Superconductor Mgx(PC)yZrNCl
Authors: Tezuka Hiroto , Kato Masatsune , Noji Takashi , Yamanaka Shoji , Koike Yoji
Published: February 2010

A new superconducting layered nitride Mg
x
(PC)
y
ZrNCl (PC: propylene carbonate) with x=0.3 has successfully been synthesized by an electrochemical Mg-intercalation technique in PC used as a solvent. From the powder X-ray diffraction measurement, PC molecules are expected to be co-intercalated with Mg. The magnetic susceptibility measurements have revealed the appearance of superconductivity with the superconducting transition temperature T
c∼15 K, which is the same as those in alkali-metal intercalation compounds A

x
ZrNCl (A=Li, Na, K). The present Mg
x
(PC)
y
ZrNCl is the first Mg-intercalated superconductor.
Fundamental Oscillation of up to 915 GHz in Small-Area InGaAs/AlAs Resonant Tunneling Diodes with Planar Slot Antennas
Authors: Shiraishi Masato , Suzuki Safumi , Teranishi Atsushi , Asada Masahiro , Sugiyama Hiroki , Yokoyama Haruki
Published: February 2010

A fundamental oscillation of up to 915 GHz was observed at room temperature in small-area InGaAs/AlAs resonant tunneling diodes (RTDs) with planar slot antennas. The dependence of the oscillation frequency on the RTD mesa area was also shown. Although the output power was small (a few tens of nanowatts) in this study owing to the relatively low available current density (difference in current density between the peak and the valley: ∼3 mA/µm2) and the small mesa area (∼0.63 µm2), it was expected that the output power can be increased by a high available current density.
Synchrotron X-ray Diffraction Study of Single-Phase β-AlN Thin Films Heteroepitaxially Grown on Sapphire (0001) Substrates by Pulsed Laser Deposition
Authors: Sumitani Kazushi , Ohtani Ryota , Yoshida Tomohiro , Nakagawa You , Mohri Satoshi , Yoshitake Tsuyoshi
Published: February 2010

β-AlN films grown on sapphire (0001) substrates by pulsed laser deposition were crystallographically evaluated by X-ray diffraction using synchrotron radiation at the SAGA Light Source. A θ–2θ measurement suggested that single-phase β-AlN was grown. From measurements of β-AlN 111 diffraction spots, it was found that β-AlN with a lattice constant of 7.90±0.06 Å was heteroepitaxially grown on the substrate with a relationship of β-AlN(111)[121] ∥ Al2O3(0001)[1120]. The film was composed of highly-oriented β-AlN crystallites with an average diameter of about 100 Å.
GaAs Nanowire and Crystallite Growth on Amorphous Substrate from Metalorganic Precursors
Authors: Statkute Gintare , Nasibulin Albert G. , Sopanen Markku , Hakkarainen Teppo , Kauppinen Esko , Lipsanen Harri
Published: February 2010

GaAs nanowires and crystallites were grown by metalorganic chemical vapor deposition from metalorganic precursors on amorphous silica obtained by thermal oxidation of 111 plane Si. The samples were characterized by scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. It was found that crystalline GaAs structures can be grown on silica.
New Green Phosphor (Ba1.2Ca0.8-xEux)SiO4 for White-Light-Emitting Diode
Authors: Park Kwangwon , Kim Jongsu , Kung Patrick , Kim Seongsin M.
Published: February 2010

A novel promising green phosphor, (Ba1.2Ca0.8-x
Eu
x
)SiO4, has been developed for low- color-temperature solid-state lighting when used in combination with near-ultraviolet light-emitting diodes. It has a unique crystal structure (hexagonal, T phase) with five different cation sites among all possible (Ba,Sr,Ca)2SiO4:Eu2+ compounds. It exhibits a broad absorption band in the near-ultraviolet region of approximately 400 nm and an intense broad green emission. It shows a slightly higher thermal quenching temperature (175 °C) than conventional yellow (Ba,Sr,Ca)2SiO4:Eu2+ phosphors (150 °C).
A Cu-Metallized InGaP/GaAs Heterojunction Bipolar Transistor with Reliable Pd/Ge/Cu Ohmic Contact for Power Applications
Authors: Huang Jui-Chien , Lin Yueh-Chin , Tseng Yu-Ling , Chen Ke-Shian , Lu Po-Chin , Lin Mong-E , Chang Edward-Yi
Published: February 2010

A Cu-metallized InGaP/GaAs heterojunction bipolar transistor (HBT) using a Pd/Ge/Cu n-type ohmic contact, a Pt/Ti/Pt/Cu p-type ohmic contact, and a Ti/Pt/Cu interconnect has been fabricated for power applications. The 4×20 µm2 HBT had an output power of 11.25 dBm with a power-added efficiency of 35.1%. After applying current-accelerated stress for 24 h, the current gain remained larger than 125. The device was also annealed at 200 °C for 24 h, and showed a slight decrease in output power from 10.06 to 9.83 dBm. The results demonstrated that reliable Cu metallization can be used for fabricating InGaP/GaAs HBTs for power applications.
X-ray Intensity Fluctuation Spectroscopy Using Nanofocused Hard X-rays: Its Application to Study of Relaxor Ferroelectrics
Authors: Ohwada Kenji , Namikawa Kazumichi , Shimomura Susumu , Nakao Hironori , Mimura Hidekazu , Yamauchi Kazuto , Matsushita Mitsuyoshi , Mizuki Jun'ichiro
Published: February 2010

The use of a combination of coherent X-rays from a third-generation synchrotron light source and ultraprecise Kirkpatrick-Baez mirrors enables us to apply nanofocused hard X-rays in solid-state physics. We developed an apparatus for X-ray intensity fluctuation spectroscopy using the nanofocused hard X-rays and applied it to the study of relaxor ferroelectrics. We have successfully detected a large and slow intensity fluctuation of scattered X-rays above cubic-to-tetragonal phase transition temperature with a characteristic time scale on the order of 10 s. We speculated that the intensity fluctuation originates from domain number fluctuation, which is directly related to the dielectric response, particularly the frequency dispersion.
Experimental Investigation of the Electrical Parameter Changes of Tuning Fork Crystal Oscillators Exposed to Air
Authors: Song Sang-Hun
Published: February 2010

We performed frequency response measurements of commercially available tuning fork crystal oscillators and analyzed their measured electrical equivalent circuit parameters of R, L, C
S, and C
P in vacuum and in air. We observed that R and L components increased as the tuning forks were exposed to air while the capacitance components C
S and C
P decreased. Of the changes of the electrical parameters for all the tested tuning forks, the resistance R showed the most significant change. These results seem to indicate that an amplitude modulation detection scheme is advantageous over a frequency modulation detection scheme in sensor applications in gaseous environment.
Ventricular function and natriuretic peptides in sequentially combined models of hypertension
Authors: Cavallero Susana , González Germán E. , Seropian Ignacio M. , Cerrudo Carolina S. , Matorra Federico , Morales Celina , Hertig Cecilia M. , Puyó Ana M. , Fernández Belisario E. , Gelpi Ricardo J.
Published: February 2010

Hemodynamic parameters and natriuretic peptide levels were evaluated in cardiac hypertrophy produced by sequentially applied renovascular (RV) and deoxycorticosterone acetate-salt (DS) models of hypertension. We studied hypertensive rats by RV or DS treatment at 2 and 4 wk, as well as by the combination of 2 wk of each treatment in an inverse sequence: RV 2 wk/DS 2 wk (RV2/DS2) and DS 2 wk/RV 2 wk (DS2/RV2). The in vivo cardiac function, interstitial fibrosis, and synthesis and secretion of types A (ANP) and B (BNP) natriuretic peptides were monitored in hypertensive models compared with their corresponding sham (Sh2, Sh4). There were no differences in relaxation parameters among RV or DS groups and combined treatments. Left ventricular +dP/d tmax increased only in RV4 ( P < 0.01 vs. Sh4), and this increase was abolished in RV2/DS2. Interstitial collagen concentration increased after 4 wk in both RV4 and RV2/DS2 groups. Although there were no changes in collagen concentration in either DS2 or DS4 groups, clipping after 2 wk of DS (DS2/RV2) remarkably stimulated interstitial fibrosis ( P < 0.01 vs. DS2). Plasma BNP increased in RV treatment at 4 wk ( P < 0.001 vs. Sh4), but not in DS. Interestingly, RV applied after the 2 wk of DS treatment induced a marked increase in BNP levels ( P < 0.001 vs. Sh4). In this regard, plasma BNP appears to be a reliable indicator of pressure overload. Our results suggest that the second stimulus of mechanical overload in combined models of hypertension determines the evolution of hypertrophy and synthesis and secretion of ANP and BNP.
Cellular Mediators of Inflammation: Tregs andTH17Cells in Gastrointestinal Diseases
Authors: Pandolfi Franco , Cianci Rossella , Pagliari Danilo , Landolfi Raffaele , Cammarota Giovanni
Published: February 2010

Human lymphocyte subpopulations were originally classified as T- and B-cells in the 70s. Later, with the development of monoclonal antibodies, it became possible to recognize, within the T-cells, functional populations:CD4+andCD8+. These populations were usually referred to as “helper” and “suppressor” cells, respectively. However several investigations within the CD8 cells failed to detect a true suppressor activity. Therefore the term suppressor was neglected because it generated confusion. Much later, true suppressor activity was recognized in a subpopulation of CD4 cells characterized by high levels of CD25. The novel population is usually referred to as T regulatory cells (Tregs) and it is characterized by the expression of FoxP3. The heterogeneity of CD4 cells was further expanded by the recent description of a novel subpopulation characterized by production of IL-17. These cells are generally referred to asTH17. They contribute to regulate the overall immune response together with other cytokine-producing populations. Treg andTH17cells are related because they could derive from a common progenitor, depending on the presence of certain cytokines. The purpose of this review is to summarize recent findings of the role of these novel populations in the field of human gastroenterological disease.
Vaccine Efficacy of Bm86 Ortholog ofH. a. anatolicum, rHaa86 Expressed in Prokaryotic Expression System
Authors: Azhahianambi P. , Ray D. D. , Chaudhuri Pallab , Gupta Rohita , Ghosh Srikanta
Published: February 2010

The use of tick vaccine in controlling ticks and tick borne diseases has been proved effective in integrated tick management format. For the control ofH. a. anatolicum, Bm86 ortholog ofH. a. anatolicumwas cloned and expressed as fusion protein inE. coliasE. coli-pETHaa86. The molecular weight of the rHaa86 was 97 kDa with a 19 kDa fusion tag of thioredoxin protein. The expressed protein was characterized immunologically and vaccine efficacy was evaluated. After 120 hours of challenge, only 26% tick could successfully fed on immunized animals. Besides significant reduction in feeding percentages, a significant reduction of 49.6 mg;P<.01in the weight of fed females in comparison to the females fed on control animals was recorded. Following oviposition, a significant reduction of 68.1 mg;P<.05in the egg masses of ticks fed on immunized animals in comparison to the ticks fed on control animals was noted. The reduction of number of females, mean weight of eggs, adult females and efficacy of immunogen were 73.8%, 31.3%, 15.8%, and 82.3%, respectively. The results indicated the possibility of development of rHaa86 based vaccine as a component of integrated control of tick species.
Multiple Positive Periodic Solutions for Delay Differential System
Authors: Hao Zhao-Cai , Xiao Ti-Jun , Liang Jin
Published: February 2010

We obtain some existence results for multiple positive periodic solutions of some delay differential systems. Examples are presented as applications. For a general positive integer m ≥ 2, main results of this paper do not appear in
former literatures as we know. Comparing with the existing results, our results are new also when m = 1.
Molluscicidal Activity of SomeSolanumSpecies Extracts against the SnailBiomphalaria alexandrina
Authors: El-Sherbini Gehad T. , Zayed Rawia A. , El-Sherbini Eman T.
Published: February 2010

Background. Snails' species are associated with transmission parasitic disease as intermediate host. Biological control stands to be a better alternative to the chemical controls aimed against snails. The search of herbal preparations that do not produce any adverse effects in the non-target organisms and are easily biodegradable remains a top research issue for scientists associated with alternative molluscicides control.Method. Solvent extracts of fresh mature leaves ofS. nigrum, S. villosum, and S. sinaicumwere tested againstBiomphalaria alexandrina, a common intermediate host ofschistosoma mansoni. A phytochemical analysis of chloroform: ethanol extract was performed to search for active toxic ingredient. The lethal concentration was determined.Results. Extracts isolated from mature leaves ofSolanumspecies were found to be having molluscicidal properties.S. nigrumextract was recorded as the highest mortality rate. When the mortality of different solvent extracts was compared, the maximum () mortality was recorded at a concentration of 90 ppm of ethanol extract ofS. nigrum.Conclusion. Extract of mature leaves ofS. nigrumexhibited molluscicidal activity followed byS. sinaicumand the less one wasS. villosum. The study provides considerable scope in exploiting local indigenous resources for snails' molluscicidal agents.
Optimal Transfer‐Ordering Strategy for a Deteriorating Inventory in Declining Market
Authors: Shah Nita H. , Shukla Kunal T.
Published: February 2010

The retailer′s optimal procurement quantity and the number of transfers from the warehouse to the display area are determined when demand is decreasing due to recession and items in inventory are subject to deterioration at a constant rate. The objective is to maximize the retailer′s total profit per unit time. The algorithms are derived to find the optimal strategy by retailer. Numerical examples are given to illustrate the proposed model. It is observed that during recession when demand is decreasing, retailer should keep a check on transportation cost and ordering cost. The display units in the show room may attract the customer.
The Spectrum of Fundus Autofluorescence Findings in Birdshot Chorioretinopathy
Authors: Giuliari GianPaolo , Hinkle David M. , Foster C. Stephen
Published: February 2010

Objective. To describe the diverse patterns observed with the use of autofluorescence fundus photography (FAF) in patients with Birdshot chorioretinopathy (BSCR).Methods. A chart review of patients with BSCR seen at the Massachusetts Eye Research and Surgery Institution, who had autofluorescence fundus photography. The data obtained included age, gender, presence of the HLA-A29 haplotype, and current treatment.Results. Eighteen eyes with HLA-A29 associated BSCR were included. Four eyes presented with active inflammation. Correspondence of the lesions noted in the colour fundus photograph was observed in 3 eyes which were more easily identified with the FAF. Fifteen eyes had fundus lesions more numerous and evident in the FAF than in the colour fundus photograph.Conclusion. Because FAF testing provides valuable insight into the metabolic state of the PR/RPE-complex, it may serve as a useful noninvasive assessment tool in patients with posterior uveitis in which the outer retina-RPE-choriocapillaries-complex is involved.
Minimally Invasive Video-Assisted Thyroidectomy and Parathyroidectomy with Intraoperative Recurrent Laryngeal Nerve Monitoring
Authors: Kandil Emad , Wassef Shafik N. , Alabbas Haytham , Freidlander Paul L.
Published: February 2010

Objective. Our goal is to study the feasibility of using intraoperative neuromonitoring (IONM) in minimally invasive video-assisted thyroidectomy and parathyroidectomy (MIVAT/P) with emphasis given to the identification of recurrent laryngeal nerve (RLN).Methods. Consecutive series of forty-seven patients with seventy-seven recurrent laryngeal nerves at risk undergoing both MIVAT/P and IONM were enrolled in this retrospective, nonrandomized analysis study. All operations were performed by the same surgeon within an academic institution setting. All patients underwent vocal cord evaluation postoperatively. Demographics and intraoperative and postoperative complications following surgery were collected.Results. Out of seventy-seven RLNs, there was one permanent unilateral RLN injury (1.29%) in a patient with advanced papillary thyroid cancer, managed by cord injection. There was another transient RLN paresis that resolved spontaneously (1.29%). There were no instances of equipment malfunction or interference.Conclusions. To our knowledge, this is the first reported MIVAT/P series from the United States of America with a standardized IONM technique. The technical feasibility of IONM seems acceptable and may serve as a meaningful adjunct to the visual identification of nerves. Neuromonitoring during MIVAT/P is effective in providing identification of laryngeal nerves and enables surgeons to feel more comfortable with MIVAT/P. Comparative series are needed for further evaluation.
A Demonstration of Modern Bayesian Methods for Assessing System Reliability with Multilevel Data and for Allocating Resources
Authors: Graves Todd L. , Hamada Michael S.
Published: February 2010

Good estimates of the reliability of a system make use of test data and expert knowledge at all available levels. Furthermore, by integrating all these information sources, one can determine how best to allocate scarce testing resources to reduce uncertainty. Both of these goals are facilitated by modern Bayesian computational methods. We demonstrate these tools using examples that were previously solvable only through the use of ingenious approximations, and employ genetic algorithms to guide resource allocation.
Congenital Circumferential Constriction Band of the Abdomen: A Case Report
Authors: Gargh Kapil , Sullivan Carol , Laing Hamish , Banerjee Sujoy
Published: February 2010

We report a case of congenital constriction band of abdomen associated with limb pseudarthrosis. The constriction band around the abdomen, though may cause initial difficulty with ventilation and parental distress, does not interfere with feeding, bowel movements, and growth. It heals spontaneously with supportive treatment though surgery may be needed in some cases.
The Effect of Novel Binary Accelerator System on Properties of Vulcanized Natural Rubber
Authors: Kamoun Moez , Nassour Abdallah , Michael Nelles
Published: February 2010

The mechanical properties, curing characteristics, and swelling behaviour of vulcanized natural rubber with a novel binary accelerator system are investigated. Results indicate that the mechanical properties were improved. Crosslinking density of vulcanized natural rubber was measured by equilibrium swelling method. As a result, the new binary accelerator was found to be able to improve both cure rate and crosslinking density. Using the numerical analysis of test interaction between binary accelerator and operational modelling of vulcanization‐factors experiments, it can be concluded that the interaction (Cystine, N‐cyclohexyl‐2‐benzothiazyl sulfenamide) was significant and the optimum value of binary accelerator was suggested, respectively, at levels 0 and +1.