Macroscopic quantum effects generated by the acoustic wave in a molecular magnet

We have shown that the size of the magnetization step due to resonant spin tunneling in a molecular magnet can be strongly affected by sound. The transverse acoustic wave can also generate macroscopic quantum beats of the magnetization during the field sweep.Comment: 4 pages, 6 figure

Rigidity and Circular slices

Let $n, m\ge 2$. Let $\Gamma<\text{SO}^\circ(n+1,1)$ be a Zariski dense convex cocompact subgroup and $\Lambda \subset \mathbb{S}^n$ its limit set. Sullivan proved in 1979 that the $\delta$-dimensional Hausdorff measure satisfies $0<\mathcal{H}^{\delta}(\Lambda)<\infty$ where $\delta$ is the Hausdorff dimension of $\Lambda$. Suppose that the ordinary set $\Omega=\mathbb{S}^n-\Lambda$ has at least two components. For a Zariski dense convex cocompact faithful representation $\rho : \Gamma \to \text{SO}^\circ(m+1,1)$ and its boundary map $f:\Lambda\to \mathbb{S}^{m}$, we present a criterion on when $\rho$ is algebraic (i.e., given by a conjugation by a M\"obius transformation on $\mathbb{S}^n$) in terms of the Hausdorff measure of all circular slices of $\Lambda$ that are mapped into circles, or more generally, into proper spheres of $\mathbb{S}^m$. More precisely, letting \Lambda_f:= \bigcup \left\{ C \cap \Lambda : \begin{matrix} C \subset \mathbb{S}^n \mbox{ is a circle such that} \\ f(C \cap \Lambda) \mbox{ is contained in a proper sphere } \mbox{of $\mathbb{S}^m$} \end{matrix} \right\}, we prove the following dichotomy: $$\text{either}\quad \Lambda_f= \Lambda \quad \text{ or } \quad \mathcal{H}^{\delta}(\Lambda_f) =0,$$ and in the former case, we have $n=m$ and $\rho$ is a conjugation by a M\"obius transformation on $\mathbb{S}^n$. Our proof uses ergodic theory and higher rank conformal measure theory for Anosov subgroups of higher rank semisimple Lie groups.Comment: 15 pages, 2 figures, New title and introductio

Rigidity of Kleinian groups via self-joinings

Let $\Gamma<\text{PSL}_2(\mathbb{C})\simeq \text{Isom}^+(\mathbb{H}^3)$ be a finitely generated non-Fuchsian Kleinian group whose ordinary set $\Omega=\mathbb{S}^2-\Lambda$ has at least two components. Let $\rho : \Gamma \to \text{PSL}_2(\mathbb{C})$ be a faithful discrete non-Fuchsian representation with boundary map $f:\Lambda\to \mathbb{S}^2$ on the limit set. In this paper, we obtain a new rigidity theorem: if $f$ maps every circular slice of $\Lambda$ into a circle, then $\rho$ is a conjugation by some $g\in \text{M\"ob}(\mathbb{S}^2)$ and $f=g|_\Lambda$. Moreover, unless $\rho$ is a conjugation, the set of circles $C\subset \mathbb{S}^2$ such that $f(C\cap \Lambda)$ is contained in a circle has empty interior in the space of all circles meeting $\Lambda$. This answers a question asked by McMullen on the rigidity of maps $\Lambda\to \mathbb{S}^2$ sending vertices of every tetrahedron of zero-volume to vertices of a tetrahedron of zero-volume. The novelty of our proof is a new viewpoint of relating the rigidity of $\Gamma$ with the higher rank dynamics of the self-joining $(\text{id} \times \rho)(\Gamma)<\text{PSL}_2(\mathbb{C})\times \text{PSL}_2(\mathbb{C})$

CULTURAL COMPETENCE LEVEL, ITS IMPORTANCE, AND EDUCATIONAL NEEDS FOR CULTURAL COMPETENCE AMONG NURSES CARING FOR FOREIGNERS IN KOREA

Purpose: This study aimed to identify cultural competency, importance, and educational requirements by analyzing nurses who were experienced in nursing foreigners in secondary hospitals and hospitals all over Korea. Methodology: A cross-sectional survey was conducted with 210 nurses from 39 hospitals in Korea. The collected data were analyzed by t-test, ANOVA, and Scheffe test. Main Findings: Satisfaction with nursing care averaged 2.48 ± 0.45. Perceived level of cultural competence averaged 2.69 ± 0.45. Cultural nursing behavior was at the highest level with 3.05±0.62; otherwise, cultural knowledge was the lowest among the subcategories (2.27±0.55). The level of importance of cultural competency was 3.69 ± 0.53. For the subcategories, cultural nursing behavior was at the highest level (3.77±0.63) and cultural awareness was at the lowest level (3.58±0.62). Training requirements had 6.83 ± 1.32, followed by cultural communication (7.34±1.50), attitudes and skills (7.04±1.50), knowledge of basics (6.83±1.33), knowledge of key concepts (6.73±1.53), and knowledge of theory and research (6.28±1.54). Implications/Applications: We suggest developing educational programs for clinical nurses to provide high-quality care to the subjects from various cultural backgrounds by strengthening cultural competency. In addition, the active support of the medical and health care institutions in improving cultural competency of nursing nurses should be emphasized

Ergodic dichotomy for subspace flows in higher rank

In this paper, we obtain an ergodic dichotomy for {\it directional} flows, more generally, subspace flows, for a class of discrete subgroups of a connected semisimple real algebraic group $G$, called transverse subgroups. The class of transverse subgroups of $G$ includes all discrete subgroups of rank one Lie groups, Anosov subgroups and their relative versions. Let $\Gamma$ be a Zariski dense $\theta$-transverse subgroup for a subset $\theta$ of simple roots. Let $L_\theta=A_\theta S_\theta$ be the Levi subgroup associated with $\theta$ where $A_\theta$ is the central maximal real split torus and $S_\theta$ is the product of a semisimple subgroup and a compact torus. There is a canonical $\Gamma$-invariant subspace $\tilde \Omega_{\theta}$ of $G/S_\theta$ on which $\Gamma$ acts properly discontinuously. Setting $\Omega_\theta=\Gamma \backslash \tilde \Omega_\theta$, we consider the subspace flow given by $A_W=\exp W$ for any linear subspace $W< \frak a_\theta$. Our main theorem is a Hopf-Tsuji-Sullivan type dichotomy for the ergodicity of $(\Omega_\theta, A_W, \mathsf m)$ with respect to a Bowen-Margulis-Sullivan measure $\mathsf m$ satisfying a certain hypothesis. As an application, we obtain the codimension dichotomy for a $\theta$-Anosov subgroup $\Gamma <G$: for any subspace $W<\mathfrak{a}_\theta$ containing a vector $u$ in the interior of the $\theta$-limit cone of $\Gamma$, we have $\operatorname{codim} W \le 2$ if and only if the $A_W$-action on $(\Omega_\theta, \mathsf{m}_u)$ is ergodic where $\mathsf{m}_u$ is the Bowen-Margulis-Sullivan measure associated with $u$.Comment: 48 pages, 1 figur

TOPO3α Influences Antigenic Variation by Monitoring Expression-Site-Associated VSG Switching in Trypanosoma brucei

Homologous recombination (HR) mediates one of the major mechanisms of trypanosome antigenic variation by placing a different variant surface glycoprotein (VSG) gene under the control of the active expression site (ES). It is believed that the majority of VSG switching events occur by duplicative gene conversion, but only a few DNA repair genes that are central to HR have been assigned a role in this process. Gene conversion events that are associated with crossover are rarely seen in VSG switching, similar to mitotic HR. In other organisms, TOPO3α (Top3 in yeasts), a type IA topoisomerase, is part of a complex that is involved in the suppression of crossovers. We therefore asked whether a related mechanism might suppress VSG recombination. Using a set of reliable recombination and switching assays that could score individual switching mechanisms, we discovered that TOPO3α function is conserved in Trypanosoma brucei and that TOPO3α plays a critical role in antigenic switching. Switching frequency increased 10–40-fold in the absence of TOPO3α and this hyper-switching phenotype required RAD51. Moreover, the preference of 70-bp repeats for VSG recombination was mitigated, while homology regions elsewhere in ES were highly favored, in the absence of TOPO3α. Our data suggest that TOPO3α may remove undesirable recombination intermediates constantly arising between active and silent ESs, thereby balancing ES integrity against VSG recombination

Growth indicators and conformal measures for transverse subgroups

We generalize Sullivan's work (1979) on conformal measures for rank one discrete subgroups to transverse subgroups of semisimple real algebraic groups. More precisely, for any Zariski dense $\theta$-transverse subgroup $\Gamma$ of a connected semisimple real algebraic group $G$, we introduce the $\theta$-growth indicator $\psi_\Gamma^{\theta}$ and prove the following: if $\nu$ is a $(\Gamma, \psi)$-conformal measure on the $\theta$-boundary $\mathcal{F}_\theta$ for a $(\Gamma, \theta)$-proper form $\psi \in \mathfrak{a}_{\theta}^*$, then $\psi\ge \psi_\Gamma^\theta$, and the $\nu$-measure of the conical set $\Lambda^{\mathsf{con}}_{\theta}$ of $\Gamma$ is equal to $1$ or $0$, depending on whether the series $\sum_{\gamma \in \Gamma} e^{-\psi(\mu_{\theta}(\gamma))}$ diverges or not. In the former case, $\psi$ is tangent to $\psi_\Gamma^\theta$ and $\nu$ is the unique $(\Gamma, \psi)$-conformal measure on $\mathcal{F}_\theta$. We also show that $\Gamma$ acts properly discontinuously on $\Lambda_\theta^{(2)}\times \mathfrak{a}_\theta$ and extend the dichotomy to include a criterion on conservativity and ergodicity of the $\mathfrak{a}_\theta$-action on the space $\Gamma \backslash \Lambda_\theta^{(2)}\times \mathfrak{a}_\theta$. This is analogous to the Hopf-Tsuji-Sullivan dichotomy on the conservativity and ergodicity of the geodesic flow for rank one locally symmetric manifolds. We discuss applications of these results as well.Comment: 51 pages, 1 figure, minor corrections are mad

Density functional calculations of the electronic structure and magnetic properties of the hydrocarbon K3picene superconductor near the metal-insulator transition

We have investigated the electronic structures and magnetic properties of of K3picene, which is a first hydrocarbon superconductor with high transition temperature T_c=18K. We have shown that the metal-insulator transition (MIT) is driven in K3picene by 5% volume enhancement with a formation of local magnetic moment. Active bands for superconductivity near the Fermi level E_F are found to have hybridized character of LUMO and LUMO+1 picene molecular orbitals. Fermi surfaces of K3picene manifest neither prominent nesting feature nor marked two-dimensional behavior. By estimating the ratio of the Coulomb interaction U and the band width W of the active bands near E_F, U/W, we have demonstrated that K3picene is located in the vicinity of the Mott transition.Comment: 5 pages, 5 figure

Ensemble averageability in network spectra

The extreme eigenvalues of connectivity matrices govern the influence of the network structure on a number of network dynamical processes. A fundamental open question is whether the eigenvalues of large networks are well represented by ensemble averages. Here we investigate this question explicitly and validate the concept of ensemble averageability in random scale-free networks by showing that the ensemble distributions of extreme eigenvalues converge to peaked distributions as the system size increases. We discuss the significance of this result using synchronization and epidemic spreading as example processes.Comment: 4 pages, 4 figure