Contraction of broken symmetries via Kac-Moody formalism

I investigate contractions via Kac-Moody formalism. In particular, I show how the symmetry algebra of the standard 2-D Kepler system, which was identified by Daboul and Slodowy as an infinite-dimensional Kac-Moody loop algebra, and was denoted by ${\mathbb H}_2$, gets reduced by the symmetry breaking term, defined by the Hamiltonian $$H(\beta)= \frac 1 {2m} (p_1^2+p_2^2)- \frac \alpha r - \beta r^{-1/2} \cos ((\phi-\gamma)/2).$$ For this $H (\beta)$ I define two symmetry loop algebras ${\mathfrak L}_{i}(\beta), i=1,2$, by choosing the `basic generators' differently. These ${\mathfrak L}_{i}(\beta)$ can be mapped isomorphically onto subalgebras of ${\mathbb H}_2$, of codimension 2 or 3, revealing the reduction of symmetry. Both factor algebras ${\mathfrak L}_i(\beta)/I_i(E,\beta)$, relative to the corresponding energy-dependent ideals $I_i(E,\beta)$, are isomorphic to ${\mathfrak so}(3)$ and ${\mathfrak so}(2,1)$ for $E0$, respectively, just as for the pure Kepler case. However, they yield two different non-standard contractions as $E \to 0$, namely to the Heisenberg-Weyl algebra ${\mathfrak h}_3={\mathfrak w}_1$ or to an abelian Lie algebra, instead of the Euclidean algebra ${\mathfrak e}(2)$ for the pure Kepler case. The above example suggests a general procedure for defining generalized contractions, and also illustrates the {\em `deformation contraction hysteresis'}, where contraction which involve two contraction parameters can yield different contracted algebras, if the limits are carried out in different order.Comment: 21 pages, 1 figur

Fabrication of minority-carrier-limited n-Si/insulator/metal diodes

A photoelectrochemical anodization technique has been used to fabricate n-Si/insulator/metal (MIS) diodes with improved electrical properties. MIS structures fabricated with Au have provided the first experimental observation of a solid-state n-Si surface barrier device whose open circuit voltage Voc is controlled by minority-carrier bulk diffusion/recombination processes. For these diodes, variation of the minority-carrier diffusion length and majority-carrier dopant density produced changes in Voc that were in accord with bulk diffusion/recombination theory. Additionally, the variation in Voc in response to changes in the work function of the metal overlayer indicated that these MIS devices were not subject to the Fermi level pinning restrictions observed for n-Si Schottky structures. X-ray photoelectron spectroscopic characterization of the anodically grown insulator indicated 8.2±0.9 Å of a strained SiO2 layer as the interfacial insulator resulting from the photoanodization process

Sea anemone model has a single Toll-like receptor that can function in pathogen detection, NF-κB signal transduction, and development

In organisms from insects to vertebrates, Toll-like receptors (TLRs) are primary pathogen detectors that activate downstream pathways, specifically those that direct expression of innate immune effector genes. TLRs also have roles in development in many species. The sea anemone Nematostella vectensis is a useful cnidarian model to study the origins of TLR signaling because its genome encodes a single TLR and homologs of many downstream signaling components, including the NF-κB pathway. We have characterized the single N. vectensis TLR (Nv-TLR) and demonstrated that it can activate canonical NF-κB signaling in human cells. Furthermore, we show that the intracellular Toll/IL-1 receptor (TIR) domain of Nv-TLR can interact with the human TLR adapter proteins MAL and MYD88. We demonstrate that the coral pathogen Vibrio coralliilyticus causes a rapidly lethal disease in N. vectensis and that heat-inactivated V. coralliilyticus and bacterial flagellin can activate a reconstituted Nv-TLR–to–NF-κB pathway in human cells. By immunostaining of anemones, we show that Nv-TLR is expressed in a subset of cnidocytes and that many of these Nv-TLR–expressing cells also express Nv-NF-κB. Additionally, the nematosome, which is a Nematostella-specific multicellular structure, expresses Nv-TLR and many innate immune pathway homologs and can engulf V. coralliilyticus. Morpholino knockdown indicates that Nv-TLR also has an essential role during early embryonic development. Our characterization of this primitive TLR and identification of a bacterial pathogen for N. vectensis reveal ancient TLR functions and provide a model for studying the molecular basis of cnidarian disease and immunity.IOS-1354935 - National Science Foundation (NSF); GRFP - National Science Foundation (NSF); GRFP - National Science Foundation (NSF); 1262934 - National Science Foundation (NSF); 2014-BSP - Arnold and Mabel Beckman Foundatio

The Absence of Extra-Tidal Structure in the Sculptor Dwarf Spheroidal Galaxy

The results of a wide-field survey of the Sculptor dwarf spheroidal galaxy are presented. Our aims were to obtain an accurate map of the outer structure of Sculptor, and to determine the level of interaction between this system and the Galaxy. Photometry was obtained in two colours down to the magnitude limits of V=20 and I=19, covering a 3.1 times 3.1 square deg area centred on Sculptor. The resulting colour-magnitude data were used as a mask to select candidate horizontal branch and red giant branch stars for this system. Previous work has shown that the red horizontal branch (HB) stars are more concentrated than the blue HB stars. We have determined the radial distributions of these two populations and show that the overall Sculptor density profile is well described by a two component model based on a combination of these radial distributions. Additionally, spectra of the Ca ii triplet region were obtained for over 700 candidate red giant stars over the 10 square deg region using the 2dF instrument on the Anglo-Australian Telescope. These spectra were used to remove foreground Galactic stars based on radial velocity and Ca ii triplet strength. The final list of Sculptor members contained 148 stars, seven of which are located beyond the nominal tidal radius. Both the photometric and spectroscopic datasets indicate no significant extra-tidal structure. These results support at most a mild level of interaction between this system and the Galaxy, and we have measured an upper mass limit for extra-tidal material to be 2.3 +/- 0.6% of the Sculptor luminous mass. This lack of tidal interaction indicates that previous velocity dispersion measurements (and hence the amount of dark matter detected) in this system are not strongly influenced by the Galactic tidal field.Comment: 53 pages, 23 figures. Accepted for publication in the Astronomical Journal. Some figures are reduced in size, and a full version is available at: ftp://ftp.mso.anu.edu.au/pub/coleman/sculptor.pd

Changes in Body Measurements of Heifers at First Parturition

Author Institution: Department of Dairy Science, Ohio Agricultural Experiment Station, Wooste

Modulation of NF-κB-dependent gene transcription using programmable DNA minor groove binders

Nuclear factor κB (NF-κB) is a transcription factor that regulates various aspects of immune response, cell death, and differentiation as well as cancer. In this study we introduce the Py-Im polyamide 1 that binds preferentially to the sequences 5′-WGGWWW-3′ and 5′GGGWWW-3′. The compound is capable of binding to κB sites and reducing the expression of various NF-κB–driven genes including IL6 and IL8 by qRT-PCR. Chromatin immunoprecipitation experiments demonstrate a reduction of p65 occupancy within the proximal promoters of those genes. Genome-wide expression analysis by RNA-seq compares the DNA-binding polyamide with the well-characterized NF-κB inhibitor PS1145, identifies overlaps and differences in affected gene groups, and shows that both affect comparable numbers of TNF-α–inducible genes. Inhibition of NF-κB DNA binding via direct displacement of the transcription factor is a potential alternative to the existing antagonists

Infinite S-expansion with ideal subtraction and some applications

According to the literature, the S-expansion procedure involving a finite semigroup is valid no matter what the structure of the original Lie (super)algebra is; however, when something about the structure of the starting (super)algebra is known and when certain particular conditions are met, the S-expansion method (with its features of resonance and reduction) is able not only to lead to several kinds of expanded (super)algebras but also to reproduce the effects of the standard as well as the generalized Inönü-Wigner contraction. In the present paper, we propose a new prescription for S-expansion, involving an infinite abelian semigroup S^(∞) and the subtraction of an infinite ideal subalgebra. We show that the subtraction of the infinite ideal subalgebra corresponds to a reduction. Our approach is a generalization of the finite S-expansion procedure presented in the literature, and it offers an alternative view of the generalized Inönü-Wigner contraction. We then show how to write the invariant tensors of the target (super)algebras in terms of those of the starting ones in the infinite S-expansion context presented in this work. We also give some interesting examples of application on algebras and superalgebras

Iwasawa N=8 Attractors

Starting from the symplectic construction of the Lie algebra e_7(7) due to Adams, we consider an Iwasawa parametrization of the coset E_7(7)/SU(8), which is the scalar manifold of N=8, d=4 supergravity. Our approach, and the manifest off-shell symmetry of the resulting symplectic frame, is determined by a non-compact Cartan subalgebra of the maximal subgroup SL(8,R) of E_7(7). In absence of gauging, we utilize the explicit expression of the Lie algebra to study the origin of E_7(7)/SU(8) as scalar configuration of a 1/8-BPS extremal black hole attractor. In such a framework, we highlight the action of a U(1) symmetry spanning the dyonic 1/8-BPS attractors. Within a suitable supersymmetry truncation allowing for the embedding of the Reissner-Nordstrom black hole, this U(1) is interpreted as nothing but the global R-symmetry of pure N=2 supergravity. Moreover, we find that the above mentioned U(1) symmetry is broken down to a discrete subgroup Z_4, implying that all 1/8-BPS Iwasawa attractors are non-dyonic near the origin of the scalar manifold. We can trace this phenomenon back to the fact that the Cartan subalgebra of SL(8,R) used in our construction endows the symplectic frame with a manifest off-shell covariance which is smaller than SL(8,R) itself. Thus, the consistence of the Adams-Iwasawa symplectic basis with the action of the U(1) symmetry gives rise to the observed Z_4 residual non-dyonic symmetry.Comment: 1+26 page

Standardised tobacco packaging:a health policy case study of corporate conflict expansion and adaptation

Objectives: To investigate opposition to standardised tobacco packaging in the UK. To increase understanding of how transnational corporations are adapting to changes in their access to policymakers precipitated by Article 5.3 of the Framework Convention on Tobacco Control (FCTC). Design: Case study web-based documentary analysis, using NVivo V.10. Examination of relationships between opponents of standardised packaging and transnational tobacco companies (TTCs) and of the volume, nature, transparency and timing of their activities. Setting: UK standardised packaging policy debate 2011-2013. Participants: Organisations selected on basis of opposition to, or facilitation thereof, standardised tobacco packaging in the UK; 422 associated documents. Results: Excluding tobacco manufacturing and packaging companies (n=12), 109 organisations were involved in opposing standardised packaging, 82 (75%) of which had a financial relationship with 1 or more TTC. These 82 organisations (43 actively opposing the measure, 39 facilitating opposition) were responsible for 60% of the 404 activities identified, including the majority of public communications and research production. TTCs were directly responsible for 28% of total activities, predominantly direct lobbying, but also financially underwrote third party research, communication, mass recruitment and lobbying. Active organisations rarely reported any financial relationship with TTCs when undertaking opposition activities. Conclusions: The multifaceted opposition to standardised packaging was primarily undertaken by third parties with financial relationships with major tobacco manufacturers. Low levels of transparency regarding these links created a misleading impression of diverse and widespread opposition. Countries should strengthen implementation of Article 5.3 of the FCTC by systematically requiring conflict of interest declarations from all organisations participating in political or media debates on tobacco control