Acceleration of protons by interplanetary shocks

Acceleration of protons by interplanetary shock

Modular chassis simplifies packaging and interconnecting of circuit boards

A system of modular chassis structures has simplified the design for mounting a number of printed circuit boards. This design is structurally adaptable to computer and industrial control system applications

Treating AIDS-associated cerebral toxoplasmosis – pyrimethamine plus sulfadiazine compared with cotrimoxazole, and outcome with adjunctive glucocorticoids

We conducted a retrospective study of AIDS-associated cerebral toxoplasmosis. Eighteen patients received pyrimethamine plus sulfadiazine and 25 co-trimoxazole, with comparable baseline characteristics. There were no differences in clinical outcomes, but co-trimoxazole was better tolerated (p = 0.066). There was also a trend towards more deaths among patients who received glucocorticoids. South African Medical Journal Vol. 97 (10) 2007: pp. 956-95

HIV-1 CRF 02 AG polymerase genes in Southern Ghana are mosaics of different 02 AG strains and the protease gene cannot infer subtypes

<p>Abstract</p> <p>Background</p> <p>Little is known about the detailed phylogeny relationships of CRF 02_AG HIV-1 polymerase genes in Ghana. The use of the protease gene of HIV-1 for subtyping has shown conflicting results.</p> <p>Methods</p> <p>The partial polymerase gene sequences of 25 HIV-1 strains obtained with Viroseq reagents were aligned with reference subtypes and alignments trimmed to a 300 bp protease, 661 bp and 1005 reverse transcriptase sequence alignments. Phylogenetic relationships of these alignments were determined with the Neighbour-Joining method using 1000 replicates and recombination patterns determined for the sequences with RIP 3.0 in the HIV sequence database.</p> <p>Results</p> <p>Unlike the other alignments, the protease gene had nodes with bootstrap values < 100% for repeat control sequences. Majority of the CRF 02_AG sequences from Ghana were made up of fragments of several strains of CRF 02_AG/AG strains. The protease gene alone is not suitable for phylogenetic analysis.</p> <p>Conclusion</p> <p>The polymerase genes of HIV-1 strains from Ghana are made up of recombinants of several CRF 02_AG strains from Ghana, Senegal and Cameroon, but the clinical implications are unknown. Using the HIV-1 protease gene for subtyping will not infer subtypes correctly.</p

Large Extra Dimension Effects on the Spin Configuration of the Top Quark Pair at e^+ e^- Colliders

Large extra dimension effects on the spin configuration of the top quark pair at the $e^+ e^-\to t\bar{t}$ process are studied. It is shown that the TeV scale quantum gravity effects cause significant deviations from the Standard Model predictions for the spin configuration in the off-diagonal basis: they lead to substantial cross sections of the like-spin states of the top quark pair, which vanish in the SM; they weaken the pure dominance of the processes, the Up-Down (Down-Up) spin states for the left-handed (right-handed) beam. In addition it is shown that the angular cut $-0.5<\cos\theta<0$ is very effective to determine the sign of the quantum gravity corrections.Comment: A discussion on the angular distribution is added with a tabl

Probing Z' gauge boson with the spin configuration of top quark pair production at future e−e+e^- e^+ linear colliders

We explore the effects of extra neutral gauge boson involved in the supersymmetric E6 model on the spin configuration of the top quark pair produced at the polarized e- e+ collider. Generic mixing terms are considered including kinetic mixing terms as well as mass mixing. In the off-diagonal spin basis of the standard model, we show that the cross sections for the suppressed spin configurations can be enhanced with the effects of the Z' boson through the modification of the spin configuration of produced top quark pair enough to be measured in the Linear Colliders, which provides the way to observe the effects of Z' boson and discriminate the pattern of gauge group decomposition. It is pointed out that the kinetic mixing may dilute the effects of mass mixing terms, and we have to perform the combined analysis.Comment: 19 pages including 5 figures, ReVTe

Spin configuration of top quark pair production with large extra dimensions at photon-photon colliders

Top quark pair production at photon-photon colliders is studied in low scale quantum gravity scenario. From the dependence of the cross sections on the spin configuration of the top quark and anti-quark, we introduce a new observable, top spin asymmetry. It is shown that there exists a special top spin basis where with the polarized parent electron beams the top spin asymmetry vanishes in the standard model but retains substantial values with the large extra dimension effects. We also present lower bounds of the quantum gravity scale $M_S$ from total cross sections with various combinations of the laser, electron beam, and top quark pair polarizations. The measurements of the top spin state $(t_\uparrow\bar{t}_\downarrow)$ with unpolarized initial beams are shown to be most effective, enhancing by about 5% the $M_S$ bounds with respect to totally unpolarized case.Comment: 18 pages, 4 figures, ReVTe

The murky distinction between self-concept and self-efficacy: beware of lurking jingle-jangle fallacies

This study extends the classic constructive dialogue/debate between self-concept and self-efficacy researchers (Marsh, Roche, Pajares & Miller, 1997) regarding the distinctions between these two constructs. The study is a substantive-methodological synergy, bringing together new substantive, theoretical and statistical models, and developing new tests of the classic jingle-jangle fallacy. We demonstrate that in a representative sample of 3,350 students from math classes in 43 German schools, generalized math self-efficacy and math outcome expectancies were indistinguishable from math self-concept, but were distinct from test-related and functional measures of self-efficacy. This is consistent with the jingle-jangle fallacies that are proposed. On the basis of pre-test-variables, we demonstrate negative frame-of-reference effects in social (big-fish-little-pond effect) and dimensional (internal/external frame-of-reference effect) comparisons for three self-concept-like constructs in each of the first four years of secondary school. In contrast, none of the frame-of-reference effects were significantly negative for either of the two self-efficacy-like constructs in any of the four years of testing. After controlling for pre-test variables, each of the three self-concept-like constructs (math self-concept, outcome expectancy, and generalized math self-efficacy) in each of the four years of secondary school was more strongly related to post-test outcomes (school grades, test scores, future aspirations) than were the corresponding two self-efficacy-like factors. Extending discussion by Marsh et al. (1997) we clarify distinctions between self-efficacy and self-concept; the role of evaluation, worthiness, and outcome expectancy in self-efficacy measures; and complications in generalized and global measures of self-efficacy

Linear sampling method for identifying cavities in a heat conductor

We consider an inverse problem of identifying the unknown cavities in a heat conductor. Using the Neumann-to-Dirichlet map as an input data, we develop a linear sampling type method for the heat equation. A new feature is that there is a freedom to choose the time variable, which suggests that we have more data than the linear sampling methods for the inverse boundary value problem associated with EIT and inverse scattering problem with near field data