Effect of the momentum dependence of nuclear symmetry potential on the transverse and elliptic flows

In the framework of the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model, effect of the momentum dependence of nuclear symmetry potential on nuclear transverse and elliptic flows in the neutron-rich reaction $^{132}$Sn+$^{124}$Sn at a beam energy of 400 MeV/nucleon is studied. We find that the momentum dependence of nuclear symmetry potential affects the rapidity distribution of the free neutron to proton ratio, the neutron and the proton transverse flows as a function of rapidity. The momentum dependence of nuclear symmetry potential affects the neutron-proton differential transverse flow more evidently than the difference of neutron and proton transverse flows as well as the difference of proton and neutron elliptic flows. It is thus better to probe the symmetry energy by using the difference of neutron and proton flows since the momentum dependence of nuclear symmetry potential is still an open question. And it is better to probe the momentum dependence of nuclear symmetry potential by using the neutron-proton differential transverse flow and the rapidity distribution of the free neutron to proton ratio.Comment: 6 pages, 6 figures, to be published by EPJ

Prospects for Detecting a Neutrino Magnetic Moment with a Tritium Source and Beta-beams

We compare the prospects for detecting a neutrino magnetic moment by the measurement of neutrinos from a tritium source, reactors and low-energy beta-beams. In all cases the neutrinos or antineutrinos are detected by scattering of electrons. We find that a large (20 MCurie) tritium source could improve the limit on the neutrino magnetic moment significantly, down to the level of a few $\times 10^{-12}$ while low-energy beta-beams with sufficiently rapid production of ions could improve the limits to the level of a few $\times 10^{-11}$. The latter would require ion production at the rate of at least $10^{15}$ s$^{-1}$.Comment: 6 pages, 3 figure

Efficient Video Indexing on the Web: A System that Leverages User Interactions with a Video Player

In this paper, we propose a user-based video indexing method, that automatically generates thumbnails of the most important scenes of an online video stream, by analyzing users' interactions with a web video player. As a test bench to verify our idea we have extended the YouTube video player into the VideoSkip system. In addition, VideoSkip uses a web-database (Google Application Engine) to keep a record of some important parameters, such as the timing of basic user actions (play, pause, skip). Moreover, we implemented an algorithm that selects representative thumbnails. Finally, we populated the system with data from an experiment with nine users. We found that the VideoSkip system indexes video content by leveraging implicit users interactions, such as pause and thirty seconds skip. Our early findings point toward improvements of the web video player and its thumbnail generation technique. The VideSkip system could compliment content-based algorithms, in order to achieve efficient video-indexing in difficult videos, such as lectures or sports.Comment: 9 pages, 3 figures, UCMedia 2010: 2nd International ICST Conference on User Centric Medi

Gene transcription analysis during interaction between potato and Ralstonia solanacearum

Bacterial wilt (BW) caused by Ralstonia solanacearum (Rs) is an important quarantine disease that spreads worldwide and infects hundreds of plant species. The BW defense response of potato is a complicated continuous process, which involves transcription of a battery of genes. The molecular mechanisms of potato-Rs interactions are poorly understood. In this study, we combined suppression subtractive hybridization and macroarray hybridization to identify genes that are differentially expressed during the incompatible interaction between Rs and potato. In total, 302 differentially expressed genes were identified and classified into 12 groups according to their putative biological functions. Of 302 genes, 81 were considered as Rs resistance-related genes based on the homology to genes of known function, and they have putative roles in pathogen recognition, signal transduction, transcription factor functioning, hypersensitive response, systemic acquired resistance, and cell rescue and protection. Additionally, 50 out of 302 genes had no match or low similarity in the NCBI databases, and they may represent novel genes. Of seven interesting genes analyzed via RNA gel blot and semi-quantitative RT-PCR, six were induced, one was suppressed, and all had different transcription patterns. The results demonstrate that the response of potato against Rs is rapid and involves the induction of numerous various genes. The genes identified in this study add to our knowledge of potato resistance to Rs

Texture as pixel feature for video object segmentation

As texture represents one of the key perceptual attributes of any object, integrating textural information into existing video object segmentation frameworks affords the potential to achieve semantically improved performance. While object segmentation is fundamentally pixel-based classification, texture is normally defined for the entire image, which raises the question of how best to directly specify and characterise texture as a pixel feature. Introduced is a generic strategy for representing textural information so it can be seamlessly incorporated as a pixel feature into any video object segmentation paradigm. Both numerical and perceptual results upon various test sequences reveal considerable improvement in the object segmentation performance when textural information is embedded

Liouville integrability of a class of integrable spin Calogero-Moser systems and exponents of simple Lie algebras

In previous work, we introduced a class of integrable spin Calogero-Moser systems associated with the classical dynamical r-matrices with spectral parameter, as classified by Etingof and Varchenko for simple Lie algebras. Here the main purpose is to establish the Liouville integrability of these systems by a uniform method

Probabilistic Simulation of Shape Instability Based on the True Microstructure Model

Shape instability belongs to one of significant types of violation for disposable structural elements under high-stress levels. Due to lack of fundamental data on materials, it is quite problematic to consider the shape instability in the design of disposable structural elements. The crystal plastic finite element method is proposed to investigate the dispersion of shape instability life data. It allows these data to be obtained from traditional material parameters. The shape instability behavior is described with the constitutive crystal model of plastic damage accumulation. Then, to improve the accuracy of life prediction, the new method is developed to construct the simulation model of true microstructure. A modeling algorithm based on the image processing technology is provided to reduce the virtual stresses from the transient crystal plastic modeling method. Comparison of experimental and predicted results shows good agreement at high stresses close to the elastic limit of the material.Одним из видов потери устойчивости является формоизменение элементов конструкции одноразового применения при высоких уровнях напряжений. Отсутствие основных данных о материалах не позволяет учесть этот параметр при их проектировании. Предложен метод конечных элементов в пластической постановке для оценки разброса данных о сроке службы элемента при его формоизменении. Для этого могут быть использованы традиционные параметры материала. Характер формоизменения описывается с помощью определяющей модели накопления пластических повреждений на кристалле. Разработан новый метод построения имитационной модели реальной микроструктуры с целью повышения точности прогнозирования срока службы. Моделирующий алгоритм, основанный на технологии обработки изображения, позволяет уменьшить эффект виртуальных напряжений при применении нестационарного метода пластического моделирования на кристалле. Сравнение экспериментальных и расчетных данных демонстрирует их хорошее соответствие при высоких напряжениях, близких к пределу упругости материала

Flux dynamics and vortex phase diagram of the new superconductor MgB2MgB_2

Magnetic critical current density and relaxation rate have been measured on $MgB_2$ bulks from 1.6 K to $T_c$ at magnetic fields up to 8 Tesla. A vortex phase diagram is depicted based on these measurement. Two phase boundaries $H_{irr}^{bulk}(T)$ and $H_{irr}^{g}(T)$ characterizing different irreversible flux motions are found. The $H_{irr}^{bulk}(T)$ is characterized by the appearance of the linear resistivity and is attributed to quantum vortex melting induced by quantum fluctuation of vortices in the rather clean system. The second boundary $H_{irr}^g(T)$ reflects the irreversible flux motion in some local regions due to either very strong pinning or the surface barrier on the tiny grains.Comment: 4 pages, 5 figure