Isoscaling and the symmetry energy in spectator fragmentation

Isoscaling and its relation to the symmetry energy in the fragmentation of excited residues produced at relativistic energies were studied in two experiments conducted at the GSI laboratory. The INDRA multidetector has been used to detect and identify light particles and fragments with Z <= 5 in collisions of 12C on 112,124Sn at incident energies of 300 and 600 MeV per nucleon. Isoscaling is observed, and the deduced parameters decrease with increasing centrality. Symmetry term coefficients, deduced within the statistical description of isotopic scaling, are near gamma = 25 MeV for peripheral and gamma < 15 MeV for central collisions. In a very recent experiment with the ALADIN spectrometer, the possibility of using secondary beams for reaction studies at relativistic energies has been explored. Beams of 107Sn, 124Sn, 124La, and 197Au were used to investigate the mass and isospin dependence of projectile fragmentation at 600 MeV per nucleon. The decrease of the isoscaling parameters is confirmed and extended over the full fragmentation regime covered in these reactions.Comment: Proceedings of the IWM2005, Catania, Italy, Nov 200

Integrable su(3) spin chain combining different representations

The general expression for the local matrix $t(\theta)$ of a quantum chain with the site space in any representation of su(3) is obtained. This is made by generalizing $t(\theta)$ from the fundamental representation and imposing the fulfillment of the Yang-Baxter equation. Then, a non-homogeneous spin chain combining different representations of su(3) is solved by developing a method inspired in the nested Bethe ansatz. The solution for the eigenvalues of the trace of the monodromy matrix is given as two coupled Bethe equations. A conjecture about the solution of a chain with the site states in different representations of su(n) is presented. The thermodynamic limit of the ground state is calculated.Comment: PlainTex harvmac, 30 pages, 7 figures, to appear in Journal of Physics

A method for solve integrable A2A_2 spin chains combining different representations

A non homogeneous spin chain in the representations $\{3 \}$ and $\{3^*\}$ of $A_2$ is analyzed. We find that the naive nested Bethe ansatz is not applicable to this case. A method inspired in the nested Bethe ansatz, that can be applied to more general cases, is developed for that chain. The solution for the eigenvalues of the trace of the monodromy matrix is given as two coupled Bethe equations different from that for a homogeneous chain. A conjecture about the form of the solutions for more general chains is presented. PACS: 75.10.Jm, 05.50+q 02.20 SvComment: PlainTeX, harvmac, 13 pages, 3 figures, to appear in Phys. Rev.

A DMRG Study of Low-Energy Excitations and Low-Temperature Properties of Alternating Spin Systems

We use the density matrix renormalization group (DMRG) method to study the ground and low-lying excited states of three kinds of uniform and dimerized alternating spin chains. The DMRG procedure is also employed to obtain low-temperature thermodynamic properties of these systems. We consider a 2N site system with spins $s_1$ and $s_2$ alternating from site to site and interacting via a Heisenberg antiferromagnetic exchange. The three systems studied correspond to $(s_1 ,s_2 )$ being equal to $(1,1/2),(3/2,1/2)$ and $(3/2,1)$; all of them have very similar properties. The ground state is found to be ferrimagnetic with total spin $s_G =N(s_1 - s_2)$. We find that there is a gapless excitation to a state with spin $s_G -1$, and a gapped excitation to a state with spin $s_G +1$. Surprisingly, the correlation length in the ground state is found to be very small for this gapless system. The DMRG analysis shows that the chain is susceptible to a conditional spin-Peierls instability. Furthermore, our studies of the magnetization, magnetic susceptibility $\chi$ and specific heat show strong magnetic-field dependences. The product $\chi T$ shows a minimum as a function of temperature T at low magnetic fields; the minimum vanishes at high magnetic fields. This low-field behavior is in agreement with earlier experimental observations. The specific heat shows a maximum as a function of temperature, and the height of the maximum increases sharply at high magnetic fields. Although all the three systems show qualitatively similar behavior, there are some notable quantitative differences between the systems in which the site spin difference, $|s_1 - s_2|$, is large and small respectively.Comment: 16 LaTeX pages, 13 postscript figure

Object selection and scaling using multimodal interaction in mixed reality

Mixed Reality (MR) is the next evolution of human interacting with the computer as MR has the ability to combine the physical environment and digital environment and making them coexist with each other. Interaction is still a huge research area in Augmented Reality (AR) but very less in MR, this is due to current advanced MR display techniques still not robust and intuitive enough to let the user to naturally interact with 3D content. New techniques on user interaction have been widely studied, the advanced technique in interaction when the system able to invoke more than one input modalities. Multimodal interaction undertakes to deliver intuitive multiple objects manipulation with gestures. This paper discusses the multimodal interaction technique using gesture and speech which the proposed experimental setup to implement multimodal in the MR interface. The real hand gesture is combined with speech inputs in MR to perform spatial object manipulations. The paper explains the implementation stage that involves interaction using gesture and speech inputs to enhance user experience in MR workspace. After acquiring gesture input and speech commands, spatial manipulation for selection and scaling using multimodal interaction has been invoked, and this paper ends with a discussion

AR-TO-KID: A speech-enabled augmented reality to engage preschool children in pronunciation learning

AR-TO-KID is an application produced for preschool children between ages five to six years old with an Augmented Reality (AR) application. The significant purpose of AR-TO-KID is to improve the pronunciation of the children in English. Hence, this paper discusses an AR application with speech input. The detection of the children speech input when they need to pronounce the words correctly, and they need to have critical thinking to identify the environment suit with the 3D objects that they will utter the word. Educational technology should be interactive and attractive for 5 to 6 years old preschool children learning; however, some at preschool teachers still used the conventional methods in teaching and children are not fully engaged with the method. Therefore, this project is to design and develop an interactive AR tool called AR-TO-KID for preschool children in pronunciation learning and teaching. This paper presents the evaluation and testing for preschool children with non-native English speaking. The article ends with results and discussion

Morphological justification of organ-preserving methods of surgical treatment of patients with liver echinococcosis

The purpose of the research is the study of the morphological structure of echinococcal cysts to assess the possibility of using organ-preserving methods of surgical treatment.Materials and methods. A clinical, instrumental, and morphological fundamental study was performed in the Surgical Clinic of the Botkin Hospital when radiation and morphological data in addition to clinical data were studied for 28 patients who underwent surgical treatment for liver echinococcosis. Excised gross specimens were examined to study the capsule structure, and the penetration of germinal elements of the cysts through membranes of the parasite (64 successively excised primary operated echinococcal cysts).Results and discussion. The fibrous capsule of the echinococcal cyst is a good barrier against Protoscolexes penetrating into the liver tissue. None of the 64 specimens studied in detail was found to have germinal elements of any echinococcal cyst penetrating through its fibrous capsule. The morphological justification of organ-preserving methods in the treatment of patients with liver echinococcosis allows a conclusion that these interventions are safe and radical

Knowledge of modifiable risk factors of heart disease among patients with acute myocardial infarction in Karachi, Pakistan: a cross sectional study

BACKGROUND: Knowledge is an important pre-requisite for implementing both primary as well as secondary preventive strategies for cardiovascular disease (CVD). There are no estimates of the level of knowledge of risk factor of heart disease in patients with CVD. We estimated the level of knowledge of modifiable risk factors and determined the factors associated with good level of knowledge among patients presenting with their first acute myocardial infarction (AMI) in a tertiary care hospital in Karachi, Pakistan. METHODS: A hospital based cross-sectional study was conducted at the National Institute of Cardiovascular Disease, a major tertiary care hospital in Karachi Pakistan. Patients admitted with their first AMI were eligible to participate. Standard questionnaire was used to interview 720 subjects. Knowledge of four modifiable risk factors of heart disease: fatty food consumption, smoking, obesity and exercise were assessed. The participants knowing three out of four risk factors were regarded as having a good level of knowledge. A multiple logistic regression model was constructed to identify the determinants of good level of knowledge. RESULTS: The mean age (SD) was 54 (11.66) years. A mere 42% of our study population had a good level of knowledge. In multiple logistic regression analysis, independent predictors of "good" level of knowledge were (odds ratio [95% confidence interval]) more than ten years of schooling were 2.5 [1.30, 4.80] (verses no schooling at all) and nuclear family system (verses extended family system) 2.54 [1.65, 3.89]. In addition, Sindhi ethnicity OR [3.03], higher level of exercise OR [2.76] and non user of tobacco OR [2.53] were also predictors of good level of knowledge. CONCLUSION: Our findings highlight the lack of good level of knowledge of modifiable risk factors for heart disease among subjects admitted with AMI in Pakistan. There is urgent need for aggressive and targeted educational strategies in the Pakistani population