Computation of stability regions for the cylindrical ion trap with no octupole electric field as compared to the corresponding results of the Paul trap.

The cylindrical ion trap is analyzed so that the octupole component of the electric field inside the trap is set to zero. As a consequence, the diameter to height ratio is computed to be 1.20 for which the quadrupole component of the cylindrical ion trap is dominant.

Comparative performance evaluation of automated segmentation methods of hippocampus from magnetic resonance images of temporal lobe epilepsy patients.

Purpose: Segmentation of the hippocampus from magnetic resonance (MR) images is a key task in the evaluation of mesial temporal lobe epilepsy (mTLE) patients. Several automated algorithms have been proposed although manual segmentation remains the benchmark. Choosing a reliable algorithm is problematic since structural definition pertaining to multiple edges, missing and fuzzy boundaries, and shape changes varies among mTLE subjects.

Theoretical investigation on confinement of ions in a cube-shaped ion trap.

The confinement of ions in a cube-shaped ion trap and the mathematical formalism governing the behavior of ions in the trap is investigated theoretically. Afterwards, the stability regions are computed using the fourth-order Rung-Kutta method. Consequently, the influence of the direction of ions, injected into the trap from its center on the stability region, is numerically discussed.

ZnFe2O4 nanoparticles as radiosensitizers in radiotherapy of human prostate cancer cells.

Nanoparticles of high-Z elements exhibit stronger photoelectric effects than soft tissues under gamma irradiation. Hence, they can be used as effective radiosensitizers for increasing the efficiency of current radiotherapy. In this work, superparamagnetic zinc ferrite spinel (ZnFe2O4) nanoparticles were synthesized by a hydrothermal reaction method and used as radiosensitizers in cancer therapy.

Surface plasmon modes of a nanoegg above a substrate.

An analytical approach describing the surface plasmon modes of a nanoegg (a nanoshell with a nonconcentric core) above a substrate is presented. The bispherical coordinate system is used for mathematical convenience. A general dispersion relation for the coupled modes as function of geometrical characteristics of the system is obtained.

Multipole plasmon excitations of C60 dimers.

We study the multipole plasmon mode frequencies of a pair of C60 molecules by means of the linearized hydrodynamic theory for electronic excitations on the each C60 surface. We apply the two-center spherical coordinate system for mathematical convenience and find an explicit form of the surface plasmon energies. Numerical result shows when approaching the two C60 molecules, the coupling between the bare plasmon modes leads to the appearance of additional modes having energies that are different from those of the isolated C60 molecules.

Inverse RNA folding solution based on multi-objective genetic algorithm and Gibbs sampling method.

In living systems, RNAs play important biological functions. The functional form of an RNA frequently requires a specific tertiary structure. The scaffold for this structure is provided by secondary structural elements that are hydrogen bonds within the molecule.

Ab initio density functional theory investigation of crystalline bundles of polygonized single-walled silicon carbide nanotubes.

By using ab initio density functional theory, the structural characterizations and electronic properties of two large-diameter (13, 13) and (14, 14) armchair silicon carbide nanotube (SiCNT) bundles are investigated. Full structural optimizations show that the cross sections of these large-diameter SiCNTs in the bundles have a nearly hexagonal shape. The effects of inter-tube coupling on the electronic dispersions of large-diameter SiCNT bundles are demonstrated.

Antinociceptive effect of intra-hippocampal CA1 and dentate gyrus injection of MK801 and AP5 in the formalin test in adult male rats.

Previous research has shown that the hippocampus processes pain related-information, probably through hippocampal neurons that respond exclusively to painful stimulation. In the current experiments we tested whether blocking NMDA receptors in the hippocampal CA1 region and dentate gyrus could reduce nociceptive behaviors in rats. The competitive and noncompetitive NMDA receptor antagonists 2-amino-5-phosphonopentanoic acid (AP5; 3.

R parity violation assisted thermal leptogenesis in the seesaw mechanism.

Successful leptogenesis within the simplest type I supersymmetric seesaw mechanism requires the lightest of the three right-handed neutrino supermultiplets to be heavier than approximately 10(9) GeV. Thermal production of such (s)neutrinos requires very high reheating temperatures which result in an overproduction of gravitinos with catastrophic consequences for the evolution of the Universe. In this Letter, we let R parity be violated through a lambda(i)N(i)H(u)H(d) term in the superpotential, where N(i) are right-handed neutrino supermultiplets.

Microinjection of ritanserin into the dorsal hippocampal CA1 and dentate gyrus decrease nociceptive behavior in adult male rat.

Prenatal 5HT depletion causes a significant decrease in the level of nociceptive sensitivity during the second phase of the formalin test behavioral response. These experiments were designed to test whether blocking 5HT2A/2c receptors in the CA1 region of the hippocampus and dentate gyrus would decrease nociceptive behaviors induced by a peripheral noxious stimulus formalin as an animal model of unremitting human being. The 5HT2A/2c receptor antagonist ritanserin (2, 4 and 8 microg/0.

Kinesthetic memory in distance reproduction task: importance of initial hand position information.

The role of the initial hand position in planning and implementation of a goal-directed movement is a matter of debate. We designed a non-visually guided repetitive reaching movement task to investigate the role of proprioceptive information of the initial or end hand position in implementation of kinesthetic memory. The experimental design consisted four experiments.

Bursting as an effective relay mode in a minimal thalamic model.

In recent years, accumulating evidence indicates that thalamic bursts are present during wakefulness and participate in information transmission as an effective relay mode with distinctive properties from the tonic activity. Thalamic bursts originate from activation of the low threshold calcium cannels via a local feedback inhibition, exerted by the thalamic reticular neurons upon the relay neurons. This article, examines if this simple mechanism is sufficient to explain the distinctive properties of thalamic bursting as an effective relay mode.

Adaptation to spiral motion: global but not local motion detectors are modulated by attention.

In this study, we investigated the effect of attention on local motion detectors. For this purpose we used logarithmic spirals previously used by Cavanagh and Favreau [Perception, 1980, 9(2), 175-182]. While the adapting stimulus was a rotating logarithmic spiral, the test stimulus was either the same spiral or its mirror image.

Subliminal attentional modulation in crowding condition.

In the crowding phenomenon, recognition of a visual target is impaired by other similar visual stimuli (distracters) presented near the target. This effect may be due largely to insufficient resolution of spatial attention. We showed that attention could subliminally enhance orientation selective adaptation to illusory lines in the crowding condition where target-distractor separation is beyond the limit of spatial resolution of attention.

Static motion aftereffect does not modulate positional representations in early visual areas.

A stationary stimulus is perceived to drift in the opposite direction after adaptation to a moving stimulus (static motion aftereffect (MAE)). It is commonly assumed that positional effects from the static motion aftereffect are mediated by early visual areas. Here we psychophysically showed that these positional effects did not modulate illusory line-tilt aftereffect (TAE).

Orientation-selective adaptation during motion-induced blindness.

When a global moving pattern is superimposed on high-contrast stationary or slowly moving stimuli, the latter occasionally disappear for periods of several seconds (motion-induced blindness, MIB). Here, an adaptation paradigm was used to determine if orientation-selective adaptation still occurs for the stimulus that is no longer visible. Two slowly drifting high-contrast Gabor patches were presented to observers.

Adaptation to apparent motion in crowding condition.

Visual adaptation has been successfully used for studying the neural activity of different cortical areas in response to visual stimuli when observers do not have explicit conscious access to those stimuli. We compared the orientation selective adaptation to apparent motion and its effect on the perception of stimuli with bistable apparent motion in crowded and non-crowded conditions. In the crowding paradigm conscious access to a visual stimulus is severely impaired when it is flanked by other similar stimuli in the peripheral visual field.

Wagon-wheel illusion under steady illumination: real or illusory?

Wheels turning in the movies sometimes appear to rotate backwards. This is called the wagon-wheel illusion (WWI). The mechanism of this illusion is based on the intermittent nature of light in films and other stroboscopic presentations, which renders them as a series of snapshots rather than a continuous visual data stream.

Orientation-selective adaptation to crowded illusory lines.

Visual adaptation has been successfully used as a psychophysical tool for studying the functional organisation of visual awareness. It has been shown that orientation-selective adaptation to a grating pattern occurs in crowded conditions. In such conditions, simultaneous presentation of flanking distractors pushes the target stimulus out of conscious perception and severely impairs orientation discrimination in the periphery of the visual field.