363 research outputs found

    Embodied learning at a distance: From sensory-motor experience to constructing and understanding a sine graph

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    Educational technologies develop quickly. Which functions of face-to-face education can be substituted by technology for distance learning? One of the risks of online education is the lack of embodied interactions. We investigate what embodied interactive technologies might offer for teaching trigonometry when learning at a distance. In a multiple case study, we analyze the potential of embodied action-based design for fostering conceptual understanding of a sine graph. It appears that independent learning with tablet-based activities leads to acquiring new sensory-motor coordinations. Some students include these new embodied experiences into mathematical discourse and trigonometry problem solving themselves, while others still need some support from a teacher. However, distantly acquired embodied experiences can be easily recalled in a few days after learning and serve well as a substrate for further conceptualization and problem-solving. The results speak for a clear contribution that embodied design might provide for grounding conceptual understanding in distance learning. However, we expect embodied design to be particularly helpful in a blended learning format

    The stability of decelerating shocks revisited

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    We present a new method for analyzing the global stability of the Sedov-von Neumann-Taylor self-similar solutions, describing the asymptotic behavior of spherical decelerating shock waves, expanding into ideal gas with density \propto r^{-\omega}. Our method allows to overcome the difficulties associated with the non-physical divergences of the solutions at the origin. We show that while the growth rates of global modes derived by previous analyses are accurate in the large wave number (small wavelength) limit, they do not correctly describe the small wave number behavior for small values of the adiabatic index \gamma. Our method furthermore allows to analyze the stability properties of the flow at early times, when the flow deviates significantly from the asymptotic self-similar behavior. We find that at this stage the perturbation growth rates are larger than those obtained for unstable asymptotic solutions at similar [\gamma,\omega]. Our results reduce the discrepancy that exists between theoretical predictions and experimental results.Comment: 10 pages, 9 figures. Accepted to ApJ; Expanded discussion of boundary condition

    Risk of sudden cardiac death in strength training

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    Physical activity is a generally accepted means of primary and secondary prevention of cardiovascular diseases, but in some cases, it can be a risk factor for cardiovascular events, including sudden cardiac death (SCD). Most studies analyze the relationship of cardiovascular events with the volume and general directions of exercise. Besides, a significant part of the guidelines and studies are devoted to the effects of aerobic exercise, while the importance of anaerobic exercise remains controversial. The review analyzes works devoted to the influence of strength training, such as weightlifting, bodybuilding, powerlifting, etc., on the cardiovascular system, as well as their relationship with SCD and other cardiovascular events. The design and contingent of the analyzed papers did not allow them to be systematized correctly. Therefore, the review is largely analytical in nature

    Minimal deformations of the commutative algebra and the linear group GL(n)

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    We consider the relations of generalized commutativity in the algebra of formal series Mq(xi) M_q (x^i ) , which conserve a tensor Iq I_q -grading and depend on parameters q(i,k) q(i,k) . We choose the Iq I_q -preserving version of differential calculus on Mq M_q . A new construction of the symmetrized tensor product for Mq M_q -type algebras and the corresponding definition of minimally deformed linear group QGL(n) QGL(n) and Lie algebra qgl(n) qgl(n) are proposed. We study the connection of QGL(n) QGL(n) and qgl(n) qgl(n) with the special matrix algebra \mbox{Mat} (n,Q) containing matrices with noncommutative elements. A definition of the deformed determinant in the algebra \mbox{Mat} (n,Q) is given. The exponential parametrization in the algebra \mbox{Mat} (n,Q) is considered on the basis of Campbell-Hausdorf formula.Comment: 14 page

    Abstract Argumentation

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    The ansamycin antibiotic, rifamycin SV, inhibits BCL6 transcriptional repression and forms a complex with the BCL6-BTB/POZ domain

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    BCL6 is a transcriptional repressor that is over-expressed due to chromosomal translocations, or other abnormalities, in ~40% of diffuse large B-cell lymphoma. BCL6 interacts with co-repressor, SMRT, and this is essential for its role in lymphomas. Peptide or small molecule inhibitors, which prevent the association of SMRT with BCL6, inhibit transcriptional repression and cause apoptosis of lymphoma cells in vitro and in vivo. In order to discover compounds, which have the potential to be developed into BCL6 inhibitors, we screened a natural product library. The ansamycin antibiotic, rifamycin SV, inhibited BCL6 transcriptional repression and NMR spectroscopy confirmed a direct interaction between rifamycin SV and BCL6. To further determine the characteristics of compounds binding to BCL6-POZ we analyzed four other members of this family and showed that rifabutin, bound most strongly. An X-ray crystal structure of the rifabutin-BCL6 complex revealed that rifabutin occupies a partly non-polar pocket making interactions with tyrosine58, asparagine21 and arginine24 of the BCL6-POZ domain. Importantly these residues are also important for the interaction of BLC6 with SMRT. This work demonstrates a unique approach to developing a structure activity relationship for a compound that will form the basis of a therapeutically useful BCL6 inhibitor
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