Elliptical flux vortices in YBa2Cu3O7

The most energetically favorable vortex in YBa2Cu3O7 forms perpendicular to an anisotropic plane. This vortex is elliptical in shape and is distinguished by an effective interchange of London penetration depths from one axis of the ellipse to another. By generalizing qualitatively from the isotropic to the anisotropic case, we suggest that the flux flow resistivity for the vortex that forms perpendicular to an anistropic plane should have a preferred direction. Similar reasoning indicates that the Kosterlitz-Thouless transition temperature for a vortex mediated transition should be lower if the vortex is elliptical in shape

Electronic Transport Spectroscopy of Carbon Nanotubes in a Magnetic Field

We report magnetic field spectroscopy measurements in carbon nanotube quantum dots exhibiting four-fold shell structure in the energy level spectrum. The magnetic field induces a large splitting between the two orbital states of each shell, demonstrating their opposite magnetic moment and determining transitions in the spin and orbital configuration of the quantum dot ground state. We use inelastic cotunneling spectroscopy to accurately resolve the spin and orbital contributions to the magnetic moment. A small coupling is found between orbitals with opposite magnetic moment leading to anticrossing behavior at zero field.Comment: 7 pages, 4 figure

Reduced hypothalamic-pituitary-adrenal axis activity in chronic multi-site musculoskeletal pain : partly masked by depressive and anxiety disorders

Peer reviewedPublisher PD

Electronic excitation spectrum of metallic carbon nanotubes

We have studied the discrete electronic spectrum of closed metallic nanotube quantum dots. At low temperatures, the stability diagrams show a very regular four-fold pattern that allows for the determination of the electron addition and excitation energies. The measured nanotube spectra are in excellent agreement with theoretical predictions based on the nanotube band structure. Our results permit the complete identification of the electron quantum states in nanotube quantum dots.Comment: 4 pages, 3 figure

Role of an intermediate state in homogeneous nucleation

We explore the role of an intermediate state (phase) in homogeneous nucleation phenomenon by examining the decay process through a doubly-humped potential barrier. As a generic model we use the fourth- and sixth-order Landau potentials and analyze the Fokker-Planck equation for the one-dimensional thermal diffusion in the system characterized by a triple-well potential. In the low temperature case we apply the WKB method to the decay process and obtain the decay rate which is accurate for a wide range of depth and curvature of the middle well. In the case of a deep middle well, it reduces to a doubly-humped-barrier counterpart of the Kramers escape rate: the barrier height and the curvature of an initial well in the Kramers rate are replaced by the arithmetic mean of higher(or outer) and lower(or inner) partial barriers and the geometric mean of curvatures of the initial and intermediate wells, respectively. It seems to be a universal formula. In the case of a shallow-enough middle well, Kramers escape rate is alternatively evaluated within the standard framework of the mean-first-passage time problem, which certainly supports the WKB result. The criteria whether or not the existence of an intermediate state can enhance the decay rate are revealed.Comment: 9pages, 11figure

The health potential of neighborhoods:A population-wide study in the Netherlands

Background: While differences in population health across neighborhoods with different socioeconomic characteristics are well documented, health disparities across neighborhoods with similar socioeconomic characteristics are less well understood. We aimed to estimate population health inequalities, both within and between neighborhoods with similar socioeconomic status, and assessed the association of neighborhood characteristics and socioeconomic spillover effects from adjacent neighborhoods. Methods: Based on Dutch whole-population data we determined the percentage of inhabitants with good or very good self-assessed health (SAH) and the percentage of inhabitants with at least one chronic disease (CD) in 11,504 neighborhoods. Neighborhoods were classified by quintiles of a composite neighborhoods socioeconomic status score (NSES). A set of spatial models was estimated accounting for spatial effects in the dependent, independent, and error components of the model. Results: Substantial population health disparities in SAH and CD both within and between neighborhoods NSES quintiles were observed, with the largest SAH variance in the lowest NSES group. Neighborhoods adjacent to higher SES neighborhoods showed a higher SAH and a lower prevalence of CD. Projected impacts from the spatial regressions indicate how modest changes in NSES among the lowest socioeconomic neighborhoods can contribute to population health in both low- and high-SES neighborhoods. Conclusion: Population health differs substantially among neighborhoods with similar socioeconomic characteristics, which can partially be explained by a spatial socio-economic spillover effect

Regional variation in type 2 diabetes:evidence from 137 820 adults on the role of neighbourhood body mass index

Background: Body mass index (BMI) is a key covariate in the study of type 2 diabetes, but can also be theorized as a contextual effect. The purpose of this study was to explore the extent to which variation in individual risk factors and neighbourhood BMI explain the variation in type 2 diabetes prevalence across neighbourhoods and municipalities. Methods: Cross-sectional data were collected from 137 820 adults aged ≥18 years from 3296 neighbourhoods in 296 municipalities in the Northern Netherlands. The odds of type 2 diabetes was assessed using a multilevel model. Median odds ratios were calculated and choropleth maps were created to visually assess neighbourhood variation in type 2 diabetes prevalence. Results: The overall prevalence of type 2 diabetes was 4%, ranging from 0 to ≥10 and 0-7% across neighbourhoods and municipalities, respectively. Of the regional variation, 67.0 and 71.6% is explained through variation of individual risk factors at the neighbourhood and municipality level, respectively. Analysis on the smallest spatial scale, i.e. the neighbourhood, best captured the regional variance. Statistically significant interaction between individual and neighbourhood BMI was found (OR = 1.06; 95% CI = 1.03-1.08, P for interaction < 0.001), adjusted for the individual risk profile. Conclusion: The results suggest a more cautious interpretation of neighbourhood effects in type 2 diabetes is warranted, and reveals the need for further investigation into risk-prone groups to guide the design of community-level interventions to halt the rise in type 2 diabetes prevalence