Position clamping of optically trapped microscopic non-spherical probes

We investigate the degree of control that can be exercised over an optically trapped microscopic non-spherical force probe. By position clamping translational and rotational modes in different ways, we are able to dramatically improve the position resolution of our probe with no reduction in sensitivity. We also demonstrate control over rotational-translational coupling, and exhibit a mechanism whereby the average centre of rotation of the probe can be displaced away from its centre

PAPPA: Primordial Anisotropy Polarization Pathfinder Array

The Primordial Anisotropy Polarization Pathfinder Array (PAPPA) is a balloon-based instrument to measure the polarization of the cosmic microwave background and search for the signal from gravity waves excited during an inflationary epoch in the early universe. PAPPA will survey a 20 x 20 deg patch at the North Celestial Pole using 32 pixels in 3 passbands centered at 89, 212, and 302 GHz. Each pixel uses MEMS switches in a superconducting microstrip transmission line to combine the phase modulation techniques used in radio astronomy with the sensitivity of transition-edge superconducting bolometers. Each switched circuit modulates the incident polarization on a single detector, allowing nearly instantaneous characterization of the Stokes I, Q, and U parameters. We describe the instrument design and status.Comment: 12 pages, 9 figures. Proceedings of the Fundamental Physics With CMB workshop, UC Irvine, March 23-25, 2006, to be published in New Astronomy Review

Rough Set Approach to Sunspot Classification Problem

Abstract. This paper presents an application of hierarchical learning method based rough set theory to the problem of sunspot classification from satellite images. The Modified Zurich classification scheme [3] is defined by a set of rules containing many complicated and unprecise concepts, which cannot be determined directly from solar images. The idea is to represent the domain knowledge by an ontology of concepts – a treelike structure that describes the relationship between the target concepts, intermediate concepts and attributes. We show that such on-tology can be constructed by a decision tree algorithm and demonstrate the proposed method on the data set containing sunspot extracted from satellite images of solar disk

The Role of Cohabitating Partner and Relationship Characteristics on Physical Activity among Individuals with Osteoarthritis

Background: Most individuals with knee or hip osteoarthritis do not meet recommendations for physical activity. The Social Cognitive Theory suggests that the social environment (e.g., spouses/partners) may influence the physical activity of individuals with osteoarthritis. The purpose of this study was to examine whether the physical activity of insufficiently active, coupled adults with osteoarthritis was associated with received partner support for physical activity, partner’s engagement in physical activity, and relationship satisfaction. Methods: Cross-sectional data from 169 couples were collected. Accelerometers estimated moderate-to-vigorous physical activity and daily steps for participants with osteoarthritis and their partners. Participants with osteoarthritis reported total received partner support for physical activity and relationship satisfaction. Results: Participants with osteoarthritis were on average 65 years old, 65% female, 86% non-Hispanic white, and 47% retired. Receiving total partner support more frequently was associated with more minutes of moderate-to-vigorous physical activity but not with steps. Relationship satisfaction moderated the association of partner’s physical activity on the daily steps of individuals with osteoarthritis such that having a partner who accomplished more daily steps was associated with participants with osteoarthritis accomplishing more daily steps themselves when they reported greater relationship satisfaction. Conclusions: Partners and relationship satisfaction may play an important role in the physical activity of individuals with osteoarthritis. Interventions seeking to increase physical activity in this population may be enhanced by promoting partner support. Additional research is needed to further explain these associations within the context of relationship satisfaction

Row-switched states in two-dimensional underdamped Josephson junction arrays

When magnetic flux moves across layered or granular superconductor structures, the passage of vortices can take place along channels which develop finite voltage, while the rest of the material remains in the zero-voltage state. We present analytical studies of an example of such mixed dynamics: the row-switched (RS) states in underdamped two-dimensional Josephson arrays, driven by a uniform DC current under external magnetic field but neglecting self-fields. The governing equations are cast into a compact differential-algebraic system which describes the dynamics of an assembly of Josephson oscillators coupled through the mesh current. We carry out a formal perturbation expansion, and obtain the DC and AC spatial distributions of the junction phases and induced circulating currents. We also estimate the interval of the driving current in which a given RS state is stable. All these analytical predictions compare well with our numerics. We then combine these results to deduce the parameter region (in the damping coefficient versus magnetic field plane) where RS states can exist.Comment: latex, 48 pages, 15 figs using psfi

Strong-correlation effects in Born effective charges

Large values of Born effective charges are generally considered as reliable indicators of the genuine tendency of an insulator towards ferroelectric instability. However, these quantities can be very much influenced by strong electron correlation and metallic behavior, which are not exclusive properties of ferroelectric materials. In this paper we compare the Born effective charges of some prototypical ferroelectrics with those of magnetic, non-ferroelectric compounds using a novel, self-interaction free methodology that improves on the local-density approximation description of the electronic properties. We show that the inclusion of strong-correlation effects systermatically reduces the size of the Born effective charges and the electron localization lengths. Furthermore we give an interpretation of the Born effective charges in terms of band energy structure and orbital occupations which can be used as a guideline to rationalize their values in the general case.Comment: 10 pages, 4 postscript figure

Efgartigimod improved health-related quality of life in generalized myasthenia gravis: results from a randomized, double-blind, placebo-controlled, phase 3 study (ADAPT)

There are substantial disease and health-related quality-of-life (HRQoL) burdens for many patients with myasthenia gravis (MG), especially for those whose disease symptoms are not well controlled. HRQoL measures such as the Myasthenia Gravis Quality of Life 15-item revised (MG-QOL15r) and EuroQoL 5-Dimensions 5-Levels (EQ-5D-5L) are vital for evaluating the clinical benefit of therapeutic interventions in patients with MG, as they assess the burden of disease and the effectiveness of treatment, as perceived by patients. The phase 3 ADAPT study (NCT03669588) demonstrated that efgartigimod-a novel neonatal Fc receptor inhibitor-was well tolerated and that acetylcholine receptor antibody-positive (AChR-Ab+) participants who received efgartigimod had statistically significant improvements in MG-specific clinical scale scores. The ancillary data reported here, which cover an additional treatment cycle, show that these participants had similar significant improvements in HRQoL measures, the MG-QOL15r and EQ-5D-5L utility and visual analog scales, and that these improvements were maintained in the second treatment cycle. Positive effects on HRQoL were rapid, seen as early as the first week of treatment in both treatment cycles, and maintained for up to 4 weeks in the follow-up-only portion of treatment cycles. The pattern of improvements in HRQoL paralleled changes in immunoglobulin G level, and correlational analyses show that improvements were consistent across HRQoL measures and with clinical efficacy measures in the ADAPT study. The substantial and durable improvements in HRQoL end points in this study demonstrate the broader benefit of treatment with efgartigimod beyond relief of immediate signs and symptoms of gMG.Neurological Motor Disorder

A multilevel neo-institutional analysis of infection prevention and control in English hospitals: coerced safety culture change?

Despite committed policy, regulative and professional efforts on healthcare safety, little is known about how such macro-interventions permeate organisations and shape culture over time. Informed by neo-institutional theory, we examined how inter-organisational influences shaped safety practices and inter-subjective meanings following efforts for coerced culture change. We traced macro-influences from 2000 to 2015 in infection prevention and control (IPC). Safety perceptions and meanings were inductively analysed from 130 in-depth qualitative interviews with senior- and middle-level managers from 30 English hospitals. A total of 869 institutional interventions were identified; 69% had a regulative component. In this context of forced implementation of safety practices, staff experienced inherent tensions concerning the scope of safety, their ability to be open and prioritisation of external mandates over local need. These tensions stemmed from conflicts among three co-existing institutional logics prevalent in the NHS. In response to requests for change, staff flexibly drew from a repertoire of cognitive, material and symbolic resources within and outside their organisations. They crafted 'strategies of action', guided by a situated assessment of first-hand practice experiences complementing collective evaluations of interventions such as 'pragmatic', 'sensible' and also 'legitimate'. Macro-institutional forces exerted influence either directly on individuals or indirectly by enriching the organisational cultural repertoire

Two-species percolation and Scaling theory of the metal-insulator transition in two dimensions

Recently, a simple non-interacting-electron model, combining local quantum tunneling via quantum point contacts and global classical percolation, has been introduced in order to describe the observed ``metal-insulator transition'' in two dimensions [1]. Here, based upon that model, a two-species-percolation scaling theory is introduced and compared to the experimental data. The two species in this model are, on one hand, the ``metallic'' point contacts, whose critical energy lies below the Fermi energy, and on the other hand, the insulating quantum point contacts. It is shown that many features of the experiments, such as the exponential dependence of the resistance on temperature on the metallic side, the linear dependence of the exponent on density, the $e^2/h$ scale of the critical resistance, the quenching of the metallic phase by a parallel magnetic field and the non-monotonic dependence of the critical density on a perpendicular magnetic field, can be naturally explained by the model. Moreover, details such as the nonmonotonic dependence of the resistance on temperature or the inflection point of the resistance vs. parallel magnetic are also a natural consequence of the theory. The calculated parallel field dependence of the critical density agrees excellently with experiments, and is used to deduce an experimental value of the confining energy in the vertical direction. It is also shown that the resistance on the ``metallic'' side can decrease with decreasing temperature by an arbitrary factor in the degenerate regime ($T\lesssim E_F$).Comment: 8 pages, 8 figure