Symmetry Energy from Systematic of Isobaric Analog States

Excitation energies to isobaric states, that are analogs of ground states, are dominated by contributions from the symmetry energy. This opens up a possibility of investigating the symmetry energy on nucleus-by-nucleus basis. Upon correcting energies of measured nuclear levels for shell and pairing effects, we find that the lowest energies for a given isospin rise in proportion to the square of isospin, allowing for an interpretation of the coefficient of proportionality in terms of a symmetry coefficient for a given nucleus. In the (A,Z) regions where there are enough data, we demonstrate a Z-independence of that coefficient. We further concentrate on the A-dependence of the coefficient, in order to learn about the density dependence of symmetry energy in uniform matter, given the changes of the density in the surface region. In parallel to the analysis of data, we carry out an analysis of the coefficient for nuclei calculated within the Skyrme-Hartree-Fock (SHF) approach, with known symmetry energy for uniform matter. While the data from isobaric analog states suggest a simple interpretation for the A-dependent symmetry coefficient, in terms of the surface and volume symmetry coefficients, the SHF results point to a more complicated situation within the isovector sector than in the isoscalar, with much stronger curvature effects in the first. We exploit the SHF results in estimating the curvature contributions to the symmetry coefficient. That assessment is hampered by instabilities of common Skyrme parameterizations of nuclear interactions.Comment: 6 pages, 3 figures; talk given at IX Latin American Symposium on Nuclear Physics and Applications, July 18-22, 2011, Quito, Ecuado

Symmetry Energy in Nuclear Surface

Interplay between the dependence of symmetry energy on density and the variation of nucleonic densities across nuclear surface is discussed. That interplay gives rise to the mass dependence of the symmetry coefficient in an energy formula. Charge symmetry of the nuclear interactions allows to introduce isoscalar and isovector densities that are approximately independent of the magnitude of neutron-proton asymmetry.Comment: 8 pages, 4 figures, contribution to 15th Nuclear Physics Workshop "Marie & Pierre Curie", Kazimierz, Poland, 2008; minor correction

Root Alternation and Verbal Plurality in Ranmo

This paper investigates morphological alternation between so-called extended and restricted roots in Ranmo, leading to a new proposal about the nature of pluractional predicates. Extended roots show properties associated with ‘pluractional’ verbs attested crosslinguistically; in particular, they are associated with both plural participant and iterative interpretations. However, they differ from typical pluractionals in the following two ways: (i) they are not morphologically formed on the basis of their restricted counterparts (which are associated with singular, punctual readings) and (ii) they are compatible with numeric modifiers. I propose that these differences can be understood under the proposal that all pluractionals obligatorily involve two components which are always distinctly represented in the semantics—PL(ural) and DEG(ree). The latter contributes a large quantity (as opposed to a simple plural) reading. However, languages vary with respect to whether these two can form a single syntactic unit (and hence be bundled into a single morpheme). This predicts a simple typology in which only a subset of so-called pluractional verbs yield a necessarily large quantity reading

Self Regulation in College-Level Mathematics Classes

This thesis investigates the need for improvement in mathematics education at the college level in the US regarding equitable practices in instruction. In particular, it focuses on understanding the role self-regulation can play in the classroom dynamics, and how self-regulation can be a way to empower students. Also included is a case study in an introductory linear algebra class at a liberal arts college and is meant to provide a investigation into a way of incorporating self-regulation by using self-paced assessments. Results of this study suggest a possible question to consider in reforming mathematics education for a more equitable environment in postsecondary mathematics classrooms

A Poem and Its Painting

Charles Bukowksi, one of the most controversial poets of the 20th century, loved very few things- alcohol, sex, his typewriter, and classical music. His poetry is considered down-to-earth and easily relatable, but it is still able to maintain a high level of artistic and literary merit. His skill as an artist becomes clear when his poem “Dostoevsky” is juxtaposed with Caravaggio’s famous painting, “The Sacrifice of Isaac.” This painting depicts an angel stopping Abraham from sacrificing his son, Isaac. Although these pieces come from different artistic media, painting versus the written word, their shocking similarities are a testament to the universality of human experience. They have the same characters, as both depict the story of a man struggling against forces he cannot understand. In addition, they have the same setup, with an intervention by a deity that delivers the protagonist to a higher state of existence. Finally, both have generally dark and despairing tones. These similarities show clearly that, thematically, both pieces glorify the idea of salvation by a higher power and are highly reverent of their respective gods