Quantum gas mixtures in different correlation regimes

We present a many-body description for two-component ultracold bosonic gases when one of the species is in the weakly interacting regime and the other is either weakly or strongly interacting. In the one-dimensional limit the latter case system is a hybrid in which a Tonks-Girardeau gas is immersed in a Bose-Einstein condensate, which is an example of a new class of quantum system involving a tunable, superfluid environment. We describe the process of phase separation microscopically and semiclassically in both situations and show that the quantum correlations are maintained in the separated phase.Comment: 4 pages, 3 figure

Brief review related to the foundations of time-dependent density functional theory

The electron density n(\rb,t), which is the central tool of time-dependent density functional theory, is presently considered to be derivable from a one-body time-dependent potential V(\rb,t), via one-electron wave functions satisfying a time- dependent Schr\"{o}dinger equation. This is here related via a generalized equation of motion to a Dirac density matrix now involving $t$. Linear response theory is then surveyed, with a special emphasis on the question of causality with respect to the density dependence of the potential. Extraction of V(\rb,t) for solvable models is also proposed

Pseudo-Goldstones from Supersymmetric Wilson Lines on 5D Orbifolds

We consider a U(1) gauge theory on the five dimensional orbifold $\mathcal{M}_4\times S^1/Z_2$, where $A_5$ has even $Z_2$ parity. This leads to a light pseudoscalar degree of freedom $W(x)$ in the effective 4D theory below the compactification scale arising from a gauge-invariant brane-to-brane Wilson line. As noted by Arkani-Hamed et al in the non-supersymmetric $S^1$ case the 5D bulk gauge-invariance of the underlying theory together with the non-local nature of the Wilson line field leads to the protection of the 4D theory of $W(x)$ from possible large global-symmetry violating quantum gravitational effects. We study the $S^1/Z_2$ theory in detail, in particular developing the supersymmetric generalization of this construction, involving a pseudoscalar Goldstone field (the `axion') and its scalar and fermion superpartners (`saxion' and `axino'). The global nature of $W(x)$ implies the absence of independent Kaluza-Klein excitations of its component fields. The non-derivative interactions of the (supersymmetric) Wilson line in the effective 4D theory arising from U(1) charged 5D fields $\Phi$ propagating between the boundary branes are studied. We show that, similar to the non-supersymmetric $S^1$ case, these interactions are suppressed by $\exp(-\pi R m_{\Phi})$ where $\pi R$ is the size of the extra dimension.Comment: LaTex, 16 page

Revisiting WebQuests in a Web 2 World. How developments in technology and pedagogy combine to scaffold personal learning

The WebQuest was launched in 1995 to scaffold advanced cognition by integrating the “ill-structured” nature of the World Wide Web with a process that guides novices through decisions and experiences that characterize experts’ behaviors. Recently, the Web has morphed into Web 2.0 with its social networking sites, blogs, wikis and podcasts. Given this richness, revisiting WebQuests is in order. This paper reviews the critical attributes of true WebQuests and reviews recent research in thinking routines and intrinsic motivation to recommend new paths for WebQuests that could scaffold student use of Web 2.0 environments, enabling a shift toward authentic personal learning.The WebQuest was launched in 1995 to scaffold advanced cognition by integrating the “ill-structured” nature of the World Wide Web with a process that guides novices through decisions and experiences that characterize experts’ behaviors. Recently, the Web has morphed into Web 2.0 with its social networking sites, blogs, wikis and podcasts. Given this richness, revisiting WebQuests is in order. This paper reviews the critical attributes of true WebQuests and reviews recent research in thinking routines and intrinsic motivation to recommend new paths for WebQuests that could scaffold student use of Web 2.0 environments, enabling a shift toward authentic personal learning

Revisiting WebQuests in a Web 2 World. How developments in technology and pedagogy combine to scaffold personal learning

The WebQuest was launched in 1995 to scaffold advanced cognition by integrating the “ill-structured” nature of the World Wide Web with a process that guides novices through decisions and experiences that characterize experts’ behaviors. Recently, the Web has morphed into Web 2.0 with its social networking sites, blogs, wikis and podcasts. Given this richness, revisiting WebQuests is in order. This paper reviews the critical attributes of true WebQuests and reviews recent research in thinking routines and intrinsic motivation to recommend new paths for WebQuests that could scaffold student use of Web 2.0 environments, enabling a shift toward authentic personal learning.The WebQuest was launched in 1995 to scaffold advanced cognition by integrating the “ill-structured” nature of the World Wide Web with a process that guides novices through decisions and experiences that characterize experts’ behaviors. Recently, the Web has morphed into Web 2.0 with its social networking sites, blogs, wikis and podcasts. Given this richness, revisiting WebQuests is in order. This paper reviews the critical attributes of true WebQuests and reviews recent research in thinking routines and intrinsic motivation to recommend new paths for WebQuests that could scaffold student use of Web 2.0 environments, enabling a shift toward authentic personal learning

Warped Axions

We study a number of realizations of axions existing in a multi-`throat' generalization of the warped throat geometry of a Randall-Sundrum slice of $AdS_5$. As argued by previous authors, the problem of generating a suitable, phenomenologically allowed Peccei-Quinn scale is simply and elegantly solved by the warping. In compactifications with two or more throats it is possible to simultaneously solve the Standard Model hierarchy problem by the Randall-Sundrum mechanism while implementing interesting warped axion models. The constructions discussed are related to holographic duals of previously studied models of composite axions arising from strongly coupled four-dimensional dynamics.Comment: 14 pages, 1 figure, references adde

Quenching small quantum gases: Genesis of the orthogonality catastrophe

We study the dynamics of two strongly interacting bosons with an additional impurity atom trapped in a harmonic potential. Using exact numerical diagonalization we are able to fully explore the dynamical evolution when the interaction between the two distinct species is suddenly switched on (quenched). We examine the behavior of the densities, the entanglement, the Loschmidt echo and the spectral function for a large range of inter-species interactions and find that even in such small systems evidence of Anderson's orthogonality catastrophe can be witnessed.Comment: 6 pages, 5 figures, Accepted for publication in Physical Review

Histone deacetylase 2 is phosphorylated, ubiquitinated, and degraded by cigarette smoke

Cigarette smoke (CS)–induced lung inflammation involves the reduction of histone deacetylase 2 (HDAC2) abundance, which is associated with steroid resistance in patients with chronic obstructive pulmonary disease and in individuals with severe asthma who smoke cigarettes. However, the molecular mechanism of CS-mediated reduction of HDAC2 is not clearly known. We hypothesized that HDAC2 is phosphorylated and subsequently degraded by the proteasome in vitro in macrophages (MonoMac6), human bronchial and primary small airway epithelial cells, and in vivo in mouse lungs in response to chronic CS exposure. Cigarette smoke extract (CSE) exposure in MonoMac6 and in bronchial and airway epithelial cells led to phosphorylation of HDAC2 on serine/threonine residues by a protein kinase CK2-mediated mechanism, decreased HDAC2 activity, and increased ubiquitin-proteasome–dependent HDAC2 degradation. CK2 and proteasome inhibitors reversed CSE-mediated HDAC2 degradation, whereas serine/threonine phosphatase inhibitor, okadaic acid, caused phosphorylation and subsequent ubiquitination of HDAC2. CS-induced HDAC2 phosphorylation was detected in mouse lungs from 2 weeks to 4 months of CS exposure, and mice showed significantly lower lung HDAC2 levels. Thus, CS-mediated down-regulation of HDAC2 in human macrophages and lung epithelial cells in vitro and in mouse lung in vivo involves the induction of serine/threonine phosphorylation and proteasomal degradation, which may have implications for steroid resistance and abnormal inflammation caused by cigarette smoke

On the Role of Context and Subjectivity on Scientific Information Systems

The explicit representation of context and subjectivity enables an information system to support multiple interpretations of the data it records. This is a crucial aspect of learning and innovation within scientific information systems. We present an ontology-based framework for context and subjectivity that integrates two lines of research: data provenance and ontological foundations of the Semantic Web. Data provenance provides a set of constructs for representing data history. We extend the definition of these constructs in order to describe multiple viewpoints or interpretations held within a domain. The W7 model, the Toulmin model, and the Proof Markup Language (PML) provide the Interlingua for creating multiple viewpoints of data in a machine-readable and sharable form. Example use cases in space sciences are used to demonstrate the feasibility and value of our approach