Duality in Graphical Models

Graphical models have proven to be powerful tools for representing high-dimensional systems of random variables. One example of such a model is the undirected graph, in which lack of an edge represents conditional independence between two random variables given the rest. Another example is the bidirected graph, in which absence of edges encodes pairwise marginal independence. Both of these classes of graphical models have been extensively studied, and while they are considered to be dual to one another, except in a few instances this duality has not been thoroughly investigated. In this paper, we demonstrate how duality between undirected and bidirected models can be used to transport results for one class of graphical models to the dual model in a transparent manner. We proceed to apply this technique to extend previously existing results as well as to prove new ones, in three important domains. First, we discuss the pairwise and global Markov properties for undirected and bidirected models, using the pseudographoid and reverse-pseudographoid rules which are weaker conditions than the typically used intersection and composition rules. Second, we investigate these pseudographoid and reverse pseudographoid rules in the context of probability distributions, using the concept of duality in the process. Duality allows us to quickly relate them to the more familiar intersection and composition properties. Third and finally, we apply the dualization method to understand the implications of faithfulness, which in turn leads to a more general form of an existing result

The reaction 13C(alpha,n)16O: a background for the observation of geo-neutrinos

The absolute cross section of the $^{13}$C($\alpha$,n)$^{16}$O reaction has been measured at E$_{\alpha}$ = 0.8 to 8.0 MeV with an overall accuracy of 4%. The precision is needed to subtract reliably a background in the observation of geo-neutrinos, e.g. in the KamLAND detector.Comment: LaTex file, 13 pages including 3 ps figures. Any request to [email protected]. Phys. Rev . C, to appea

Relativistic continuum-continuum coupling in the dissociation of halo nuclei

A relativistic coupled-channels theory for the calculation of dissociation cross sections of halo nuclei is developed. A comparison with non-relativistic models is done for the dissociation of $^{8}$B projectiles. It is shown that neglecting relativistic effects leads to seizable inaccuracies in the extraction of the astrophysical S-factor for the proton+beryllium radiative capture reaction.Comment: 4 pages, 2 figures, version accepted for publication at Physics Review Letter

Theoretical photo-disintegration of 16^{16}O

The photodisintegration of $^{16}$O is predicted to be dominated by $E$2 excitation in the vicinity of the $\alpha$-particle threshold. The reaction rates of $^{12}$C($\alpha$,$\gamma$)$^{16}$O are expected to be determined from this reaction.Comment: 3 pages, 2 figures, Proceedings of Nuclei in the Cosmos (NIC-XIV). 19-24 June 2016, Niigata, Japa

Foods of the Future

Frozen foods will be popular in the homemaker\u27s new kitchen, says Shirley Rolf

Parallel Tracks: Three Case Studies of the Relationship between Street Art and U.S. Museums in the Twenty-First Century

An examination of three case studies involving U.S. museum exhibitions of street and graffiti art in the twenty-first century. This thesis covers the Brooklyn Museum of Art’s “Graffiti” show in 2006, Los Angeles’s Museum of Contemporary Art’s “Art in the Streets” in 2011, and the 2012-2015 activities of the Baton Rouge Museum of Public Art. These events offer a chronological and geographical range to provide a broad scope of investigation into the pitfalls and opportunities of museum’s exhibiting graffiti and street art. The heart of this research is not to prolong the debate about whether museums endanger their authority when they show street artists or whether street artists lose their edge by engaging with institutions, but rather, to accept their long-standing relationship as a fact and historicize the challenges that have faced these parties over many years. In each instance covered here, the museum’s objective was to harness and convey the energy and value of street art to new audience. Each museum setting sought to demonstrate the communicative power of graffiti and other forms of transgressive urban art. At some cost to the institution, their efforts had significant, positive consequences on the art form, whether in the art market or in the public domain. The catalog of the obstacles which faced these organizations, as laid out in this research, will enable museums to mitigate those costs in the future and contribute to a road map which museums can use to better navigate the parallel paths of subversion and compromise they themselves accept when supporting controversial art

Investigation of the anti-migratory properties of GSK-3 inhibitors in glioblastoma

Glioblastoma is the most malignant form of brain cancer. Due to its aggressive nature, extensive research has been performed, but little progress has been made in identifying effective treatment options. Glycogen synthase kinase-3 (GSK-3) is a ubiquitous, multifaceted protein kinase. Previous studies have shown that small molecule inhibitors of GSK-3 block the migration of glioblastoma cells and may prevent spread of tumor in the brain. However, these studies were performed using non-selective GSK-3 inhibitors (LiCl and an indirubin derivative, BIO); thus, it was unclear whether GSK-3 was the most important target. In this study, we used recently generated highly selective GSK-3 inhibitors (CHIR99021, AZD1080, and AZD2858, as well as BIO) to investigate these questions. These were applied to four glioblastoma cell lines: G30, G9, U251, and U1242, in three migration assays: transwell, spheroid, and wound healing (scratch) assay to further assess the suitability of GSK-3 as a target in glioblastoma. We also utilized the ATP Luciferase reporter assay for cell viability to assess the influence of our panel of drugs on cell migration versus viability. In addition, the TOPFlash Luciferase reporter assay was performed as an indicator of the level of GSK-3 inhibition. The TOPFlash assay showed that all GSK-3 inhibitors were able to increase luciferase levels. This indicates that GSK-3 was inhibited in our cells after drug treatment. The transwell assays showed us that the GSK-3 inhibitors were able to block migration significantly in all cell lines tested in a dose-dependent manner. The effectiveness of GSK-3 inhibition in the three-dimensional collagen spheroid assays was cell line-dependent, with the non-selective GSK-3 inhibitor BIO showing the most potent effects. Cell migration was not blocked by any of the three selective GSK-3 inhibitors in the wound healing scratch assay. Thus we have found that the three distinct highly selective inhibitors of GSK-3 block glioblastoma cell migration, but only work consistently in the transwell assay. Therefore, we conclude that GSK-3 might be important in the contraction and morphological changes necessary for glioblastoma cells to migrate through the 8 micron pores in the transwell. Further investigation into this observation is necessary. Though results were variable between assays, we conclude that the inhibition of GSK-3 is a promising potential therapeutic strategy for glioblastoma treatment

Resonances and the thermonuclear reaction rate

We present an approximate analytic expression for thermonuclear reaction rate of charged particles when the cross section contains a single narrow or wide resonance described by a Breit-Wigner shape. The resulting expression is uniformly valid as the effective energy and resonance energy coalesce. We use our expressions to calculate the reaction rate for $^{12}$C(p,$\gamma$)$^{13}$N.Comment: 4 pages, 1 figure, presented at the VIII International Conference on Nucleus-Nucleus in Moscow (Russia) on June 17-21, 200