Berry phases and zero-modes in toroidal topological insulator

An effective Hamiltonian describing the surface states of a toroidal topological insulator is obtained, and it is shown to support both bound-states and charged zero-modes. Actually, the spin connection induced by the toroidal curvature can be viewed as an position-dependent effective vector potential, which ultimately yields the zero-modes whose wave-functions harmonically oscillate around the toroidal surface. In addition, two distinct Berry phases are predicted to take place by the virtue of the toroidal topology.Comment: New version, accepted for publication in EPJB, 6 pages, 1 figur

On topological spin excitations on a rigid torus

We study Heisenberg model of classical spins lying on the toroidal support, whose internal and external radii are $r$ and $R$, respectively. The isotropic regime is characterized by a fractional soliton solution. Whenever the torus size is very large, $R\to\infty$, its charge equals unity and the soliton effectively lies on an infinite cylinder. However, for R=0 the spherical geometry is recovered and we obtain that configuration and energy of a soliton lying on a sphere. Vortex-like configurations are also supported: in a ring torus ($R>r$) such excitations present no core where energy could blow up. At the limit $R\to\infty$ we are effectively describing it on an infinite cylinder, where the spins appear to be practically parallel to each other, yielding no net energy. On the other hand, in a horn torus ($R=r$) a singular core takes place, while for $R<r$ (spindle torus) two such singularities appear. If $R$ is further diminished until vanish we recover vortex configuration on a sphere.Comment: 11 pages, 9 figure

The Phillips curve and information rigidity in Brazil

This work aims at testing the null hypothesis of no sticky information against the alternative of sticky information using Brazilian data. The rejection of the null hypothesis allows us to derive the expected time between information updates. The median of market participants' predictions collected by Gerin/Bacen is used as a proxy to firms' expectation contained in the sticky information version of the Phillips curve. Our estimates imply that inflation expectations in Brazil are updated about once each five quarters, which in part can be attributed to reduced uncertainty about Brazilian inflation in the period of analysis.O objetivo deste trabalho é testar a hipótese de ausência de rigidez de informação no Brasil. A metodologia permite também derivar a frequência de reajuste informacional via Curva de Phillips sob Rigidez de Informação. Para tanto, a mediana das projeções de mercado divulgadas pela Gerin/Bacen são utilizadas como proxy para as expectativas contidas na curva de Phillips. As estimativas obtidas são consistentes com o modelo e implicam em atualização de informação a cada cinco trimestres. Portanto, o período de atualização de informações estimado para o Brasil é próximo de alguns estimados para países europeus e norte americanos, o que em parte pode ser atribuído à redução nas incertezas inflacionárias brasileiras no período de análise

On multigraded generalizations of Kirillov-Reshetikhin modules

We study the category of Z^l-graded modules with finite-dimensional graded pieces for certain Z+^l-graded Lie algebras. We also consider certain Serre subcategories with finitely many isomorphism classes of simple objects. We construct projective resolutions for the simple modules in these categories and compute the Ext groups between simple modules. We show that the projective covers of the simple modules in these Serre subcategories can be regarded as multigraded generalizations of Kirillov-Reshetikhin modules and give a recursive formula for computing their graded characters

Scattering and Trapping of Nonlinear Schroedinger Solitons in External Potentials

Soliton motion in some external potentials is studied using the nonlinear Schr\"odinger equation. Solitons are scattered by a potential wall. Solitons propagate almost freely or are trapped in a periodic potential. The critical kinetic energy for reflection and trapping is evaluated approximately with a variational method.Comment: 9 pages, 7 figure

Patient-reported financial barriers to adherence to treatment in neurology

OBJECTIVE: Many effective medical therapies are available for treating neurological diseases, but these therapies tend to be expensive and adherence is critical to their effectiveness. We used patient-reported data to examine the frequency and determinants of financial barriers to medication adherence among individuals treated for neurological disorders. PATIENTS AND METHODS: Patients completed cross-sectional surveys on iPads as part of routine outpatient care in a neurology clinic. Survey responses from a 3-month period were collected and merged with administrative sources of demographic and clinical information (eg, insurance type). We explored the association between patient characteristics and patient-reported failure to refill prescription medication due to cost in the previous 12 months, termed here as "nonadherence". RESULTS: The population studied comprised 6075 adults who were presented between July and September 2015 for outpatient neurology appointments. The mean age of participants was 56 (standard deviation: 18) years, and 1613 (54%) were females. The patients who participated in the surveys (2992, 49%) were comparable to nonparticipants with respect to gender and ethnicity but more often identified English as their preferred language (94% vs 6%, p<0.01). Among respondents, 9.8% (n=265) reported nonadherence that varied by condition. These patients were more frequently Hispanic (16.7% vs 9.8% white, p=0.01), living alone (13.9% vs 8.9% cohabitating, p<0.01), and preferred a language other than English (15.3% vs 9.4%, p=0.02). CONCLUSION: Overall, the magnitude of financial barriers to medication adherence appears to vary across neurological conditions and demographic characteristics

Oral Health-Related Quality of Life in Brazilian Patients Wearing Three Types of Lower Dentures: Psychosocial and Clinical Aspects

The purpose of this study was to evaluate the oral health-related Quality of Life (QoL) of patients with edentulous lower jaws rehabilitated with conventional or implant-supported dentures. In the quest for greater QoL, especially among the elderly, it is important to evaluate how the use of dentures impacts physical and emotional well-being. Brazilian health care policy makers should be informed of the advantages of rehabilitation with implant-supported dentures. A cohort of 78 edentulous seniors was divided into three groups of 26 according to denture type: Conventional (CD), Implant-Supported Overdenture (IOD) and Fixed-Implant Prosthesis (FIP). To evaluate QoL, clinical and sociodemographic information was collected and the OHIP-20 questionnaire was administered, using a 5-point frequency scale, including a “don’t know” option. Chewing and pronunciation were less impacted in FIP and IOD than in CD (p=0.013 and p=0.027, respectively), while patients in the CD group reported more adaptation difficulties (p=0.006) and more frequent avoidance of hard-to-chew foods (p=0.032). The majority reported no interference of dentures with appearance and social life, regardless of denture type. Depending on the patient’s biological and financial circumstances, implant-supported dentures is the form of rehabilitation of edentulism providing the greatest improvement in QoL. The reported limitations and difficulties had no significant impact on satisfaction and QoL

Topological insulator particles as optically induced oscillators: towards dynamical force measurements and optical rheology

We report the first experimental study upon the optical trapping and manipulation of topological insulator (TI) particles. By virtue of the unique TI properties, which have a conducting surface and an insulating bulk, the particles present a peculiar behaviour in the presence of a single laser beam optical tweezers: they oscillate in a plane perpendicular to the direction of the laser propagation, as a result of the competition between radiation pressure and gradient forces. In other words, TI particles behave as optically induced oscillators, allowing dynamical measurements with unprecedented simplicity and purely optical control. Actually, optical rheology of soft matter interfaces and biological membranes, as well as dynamical force measurements in macromolecules and biopolymers, may be quoted as feasible possibilities for the near future.Comment: 6 pages, 5 figures. Correspondence and requests for Supplementary Material should be addressed to [email protected]